E39 Wheel Speed Sensor Replacement

[Teuobk]

Hi guys. I just got done replacing one of my ABS/DSC wheel speed sensors on my 540i and thought I'd write about it. I've had two sensors fail over the past two years, and I was able to use the concepts below both times. The actual sensor replacement is trivial; the tricky part is figuring out which sensor failed. I hope that this can help somebody!

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Replacement of Wheel Speed Sensor
E39 BMW

Synopsis: A malfunctioning wheel speed sensor can cause the anti-lock braking and traction control systems to become disabled, among other things.

Symptoms: Three lights appear simultaneously on the dashboard: ABS, an amber BRAKE, and the triangular "traction lost" icon. Traction control is not operational, nor is antilock braking. One or more of the speedometer, odometer, or cruise control might also be inoperable.

Tools required: Multimeter capable of testing diodes. 5 mm Allen wrench. Long, very narrow probes for multimeter, or equivalent. For rear sensors, a 10 mm socket, 8 mm socket, flat-head screwdriver, and needle-nose pliers might be required to remove trim.

Difficulty: Easy

Diagnosis: A BMW service computer can isolate the source of the problem; standard OBDII code readers cannot pull the requisite information. The Peake Research code reader seems to be capable of reporting whether or not a problem exists, but there do not appear to be any codes that reveal the location of the faulty sensor. If a wheel speed sensor is suspected, and no computer is available, the identification process is one of trial and error. Jack up you car and support appropriately. Access to the sensor is considerably easier with the wheel removed, so pick a corner and remove the wheel.

It is worth noting that certain failure modes are associated with particular corners of the car. If the speedometer and odometer do not work, the driver's side rear sensor is probably bad. If the speedometer works but the cruise control does not, then the passenger side rear senor is probably bad.

Locate the sensor (mounted on the wheel carrier near the hub) and trace its wire back to a blue connector. The connector might be housed in a black plastic box. Open the hinged box if it is present. There might be a second connector next to the blue speed sensor connector; that's for the brake pad wear sensor. Pull the blue speed sensor connector out of the box and disconnect the two sides.

Deep inside the sensor side of the connector, there are two metal prongs. Now comes the tricky part. Turn the mutimeter on and to its diode testing setting (it looks like an arrow with a line in front of it). Connect one probe to one of the prongs, and the other probe to the other prong. The meter should read ~1.4-1.8 V or indicate an "open" condition (e.g., "OL"). Reverse the probes. Once again, the meter should indicate either an open condition or a 1.4-1.8 V drop, but the result should be whichever one you didn't see the first time. If you see any other result, such as 600 mV in each direction or 0.0 V in either direction, you've probably found the bad sensor; congratulations! Note that a 0.0 V drop is possibly indicative of a poor test setup; verify that you are not shorting the multimeter probes. If the sensor tests out okay, try again at a different wheel. Of course, it's always possible that one of your speed sensors has failed in a way that wouldn't present itself in this test. In the worst case, you'd have to go to the dealer anyway for the diagnosis.

You might want to try another wheel even if you think you found the bad sensor in order to confirm that your technique is good. It's sometimes a bit tricky to get a good connection to those prongs. If you think you found two bad sensors, you probably messed up.

Be sure to reconnect all of the sensors that you believe are good. Once you have identified the faulty sensor, obtain a replacement BMW part. One sensor on my 540i was $120; I've read reports of them retailing for as little as $70.

Other possible causes: Reports indicate that the cause of the sensor failure might be a frayed wheel-speed sensor wire in the wheel well; inspect the entire visible run of the cable carefully to confirm the lack of frayed or pinched wires. If frayed wires are found, attempt repair using common wire-repair techniques. Other reports indicate that a bad ABS controller might cause similar symptoms.

Replacement: With the wheel off at the corner with the broken sensor, and the sensor cable disconnected, unsnap the sensor wire from the two mount points on the steering knuckle. Follow the cable to the point where it ends at the sensor. The sensor is attached to the car with one or two small bolts. A 5mm Allen wrench is required to remove the bolts. You might have to do this blind, but it's not that hard. After the bolts are removed, gently pull the sensor straight out of its hole. Put the new sensor where the old one was, and reverse the removal process. There were two bolts holding my old front sensor, but the new front sensor included only one mounting hole. Due to the sensor construction, I don't believe it is a problem to use only one bolt. Be sure to hook the new sensor back to the other connector, and don't forget to snap the cable into the cable brackets.

Commentary: I have had two speed sensors fail on my 1999 540i. The first time, a front sensor failed. The DSC, ABS, and brake warning lights were be off when the car was first started but would turn on after driving a couple hundred feet. A year later, a rear sensor failed. The same three lights shone at startup and never reset. The Peake reader indicated code 0F 78. I was able to use the above procedure both times to successfully locate the failed sensor.

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Jeff

[Hotswimmer]

Hey Jeff,

Thank you very much for taking the time to post this. Could I suggest that you also post it to the E39 FAQ thread in this forum so it's easier for people to locate and it doesn't just disappear in a few days?

Thanks again.

[ataie]

so were is the sensor itself? left or right rear? thanks

[masurati]

so if rear wheel sensor is unpluged odometer stops counting miles?

[ataie]

ok, I had the ABS, DSC, brake, and check engine lights on. All amber.

check engine code was 500, which is wheel speed sensor. My mechanic replaced the sensor and cleared the engine code. The ABS, DSC and brake light still remained on. after driving for about 25 miles the check engine light came back on. code 500 - wheel speed sensor. so what next? do I need to change the front one now? what else can I check? thanks

[ataie]

can git rid of the light....

I've changed both rear and one front sensor (one at the time to save money), and after 20 miles or so the 'check engine' light comes on with code P0500 which is speed sensor.

the ABS, DSC, & 'brake' lights remain on in amber. some mornings when the car is started there is no light on, then about 2-3 miles they come back on.

what next???

[ataie]

now ALL 4 wheel sensors have been changed- 3 lights remain on along with 'CEL' reading code P0500. would a faulty ABS module case all these lights to come on?

[KOLYAtheDJ]

what if my DSC light is on, and both speedometer and cruise control are working?
DSC light comes on every time i pass 17.5 mph when i start the car and stays on until i turn the car off.
any thoughts

[fuddyduddy121]

now ALL 4 wheel sensors have been changed- 3 lights remain on along with 'CEL' reading code P0500. would a faulty ABS module case all these lights to come on?

I'm wondering where the main speed sensor really is - is it on the driveshaft or one of the wheels?

[ataie]

anyone know how to reset the DSC??? dealer what's to charge one hour labor to do it.

new ABS module as well as 4 new wheel speed sensors. ABS, DSC, brake lights are on. Peake reader gives me error on this car, and OBDII doesn't see any code. I just need to reset it.

[Dan]

Hey Jeff,

Thank you very much for taking the time to post this. Could I suggest that you also post it to the E39 FAQ thread in this forum so it's easier for people to locate and it doesn't just disappear in a few days?

Thanks again.
i sent him an email about this... good call Randy! good write-up's like this is what the FAQ needs.

[biyiojones]

Thanks a lot for the procedure it realy help, it worked with mine. it saved me a lot of money , i was able to fix the abs sensor by just doing some wire repair.

[Weboddity]

My 528i has all of the symptoms described. The speedometer, odometer and cruise control were working every morning for my ~7 mile trip to work, where I turn the car off for about ten minutes. When I start the vehicle again none of those things work and pretty much won't work for the rest of the day, though occasionally they kick back on. I start my car again at least 3 more times from that point to the end of the day. I had the sensors swapped from left to right in the rear and now it doesn't work at all.

I am going to replace the rear sensors and post an update. Thank you for this post.

[bimmerfiver]

Good post man. :buttrock

Here is my BMW Peake Scanner Model R2D2. He works my codes:

[mefff]

Good post...just a little additional info.... No matter how careful you are and after the sensor breaks at the hub housing like both mine did... don't sweat the small stuff. Just give it a real good spray around the outside with wd40 or Liquid Wrench or whatever you prefer. Then gently tap behind the broken part all the way round with a small punch to loosen it. After about 10 minutes firmly pull on the remaining broken part. If it rips off at the wires like mine both did.... simply use a 1/8 drill and drill into the remaining piece about 1 inch... now screw a metal screw a little larger than 1/8th firmly into the drilled hole. Next put a pair of long nose pliers below the neck of the screw sticking out and pry from behind on the pliers with a small bar or screwdriver. It'll come strait out with a bit of work. After its removed, take your garden hose and firmly spray into the sensor hole to remove any mud or gravel from the sensor. Mine were both full of crap. A little wd40 on the new one and she slides right in.
Regards Mefff

[Weboddity]

I am going to replace the rear sensors and post an update. Thank you for this post.

I replaced the rear sensors, which has not corrected my problem (see my previous post). The speedometer has gone back to intermittently (but usually not at all) working.

I spoke to someone I know that works on BMWs for a dealership, who said that the problem is most commonly a result of a bad DSC module. He said that the modules going bad is a common problem, and that it is the most likely and hence should be my starting point. He then said that if that failed, it could be because of what BMW calls the Komvi, which from what it sounds like a lot of things report to and is also responsible for the display of the mileage.

He said that the dealership has often replaced the Komvi unit if the display of mileage has a bad pixel as a "good will" fix, and seemed to indicate that they kind of did it because the mileage has to be properly displayed (legally?); he is unsure of whether or not the dealership would replace the Komvi if it is bad but has a proper display of pixels.

I think my smartest next step would be to pay a business to diagnose the problem via a computer. That way I don't drop even more money without being absolutely certain that the problem will go away.

[FP5241]

bump... :shifty

[JShare]

I was working on my 740iL so it should be the same for the E39 I imagine. First, thanks for the original post. Checking these things is a bit of a pain so some details may save you some time. I have checked all my wheel sensors and this is what I came up with.

Front: If you are not inclined to pull the wheels you do not need to. If you are checking the left front then turn the wheel to the right and get at the conection box from the rear side of the wheel and vs versa for the right. The box hinges forward. A flathead help with getting it open. Once I had it open I tried using two aligator clips. This is too big. I successfully used one aligator and one wire. Eventually I went to using two wires. The way I did it was cut about a 3 inch piece of wire and strip one side. I then took the probe of my multmeter and de-virginized the non-stripped end so it slide over the pin a little easier. I then took each wire and slide the non-stripped end over each pin in the wheel sensor connector, so you end up two wires with the stripped end hanging out, ready to be tested. The values I got on my fluke were about a 1.97-1.99 v Drop for all four. I after I checked each with the multimeter I cranked the wheel back the other way and pulled the sensor and visually checked it. I ended up bending one of the pins slightly and just bend it back with my pinky.

Rear: On the first one I jacked it and pulled the wheel. On the second one I didn't pull the wheel. Of course you can't crank the wheel so it's a bit more painfull, but it was still quicker than jacking and removing the wheel. Depending on how much space you have in your wheel well and how big your forearms are it may not be an option.

Varsity move: If you don't feel you need to check the sensor visually or even if you do, why not check them from the ABS module. This would not only identify an open wheel speed sensor it would identify bad wiring between the ABS module and the sensor. The catch is you need to know which pins go to the wheel speed sensors. I have a Bosch 5.7 on the 740. I pulled the electrical conector off the control module and started checking between the pin holes with two wire and the multimeter. I found that I got a 1.97-1.99v drop and they passed the test as a diode between pins 12-28, 13-29, 30-31, 15-16. I did not spend the time figuring out which sensor goes to which pin.

Unfortunately or fortunately all my sensors checked good. This means my ASC light is probably the module itself. I am still working it.

[scushkadee]

hi. just wondering if you figured out if it was the module??

[luyckxj]

On a E39 the Electronic Control Module Connectors are:
pin 12 / pin 28 : Left Front Speed Sensor
pin 13 / pin 29 : Left Rear Speed Sensor
pin 15 / pin 16 : Right Front Speed Sensor
pin 30 / pin 31 : Right Rear Speed Sensor

See also
pag. ELE-15 of ABS/DSC controle module (A65)
or
pag. ELE-21 of ABS/ASC controle module (A52)

both in the Volume II of the
"BMW 5 Series - Service Manual" of the "Bentley Publishers"
(by the way, recommendable)
See: http://www.bentleypublishers.com/product.htm?code=B502

[Mark540i]

It is advised that during installation to apply a thin coat of Staburags NBU 12/K to speed sensor and housing.

What else can we use to grease this sucker?

[dnifong]

OK, I had all three lights. "Brake ABS and DSC." I took the car to the dealer. they told me it was the module. I sent mine to bba reman. they stated mine was not repairable, so purchased a remanufactured unit from them. 650 bucks. the new module cleared the "brake and abs lights", but not the DSC light. so I carried it back to the dealer. they said it is the steering angle sensor. WTH? can I trouble shoot this sensor before I purchase it?

thanks for your help. I have spent to much money and time to let them fix it now. dale

[jnyost]

Damn dude. I sell them for $450.

[robotz991]

I need a DSC controller for a 2001 525 built in 9/00 already replaced the fault reported, front right sensor.. nothing changed except my bank account balance..

The shop and I are confident it's the controller and not the sensor.. i need to make sure he doesnt thow that one away!!

lets talk

[jnyost]

PM replied.

[JuanK20]

just replaced the driver's side rear speed sensor. speedo still doesnt work. crap. im gonna try replacing the passenger side now

[M3 Euro LTW]

simply use a 1/8 drill and drill into the remaining piece about 1 inch... now screw a metal screw a little larger than 1/8th firmly into the drilled hole. Next put a pair of long nose pliers below the neck of the screw sticking out and pry from behind on the pliers with a small bar or screwdriver.

This is a great tip....

I have an INPA that will tell you what wheel sensor is bad, that helps take out the guesswork. Didn't try my snap-on MT2500, but these are getting cheaper and cheaper on ebay, and probably would identify which sensor it is, along of course with doing many other diagnostic jobs.

My mechanic told me to drill it out, through and through, and use picks and needle nose pliers to pull out the bits... I started the drilling, got tired, and just left it up on the lift. But THIS tip is great, and I'm going to thread in the screw next... great idea.

Love BFC for little tid-bits like this.

(Just swapped out the PS pump, man.... I never knew the steering could ber as good as it is now...must have been bad since day one I bought it used!)

BTW, on that subject, I was shocked at how affordable a reman PS pump was at the local autozone. $152..... Dealer list was $960 Course, that was for a new one. But even there.... a new ZF from Vines was all of $375. Maybe the dealers are forced to buy via Germany?

That sensor was a B)(*^ to get out.....

I couldn't drill out any more pieces, and was completely frustrated at some point, and just gave up last night.

Good thing too.... when I re-started today, I took off the calliper, and rotor, and loosened the P-brake pads just enough to allow access tothe dust sheild,and pull out the 4 bolts to that. This allowed a better view "down the hole" and better angles. Still couldn't figure out what was left in there.

At that point...(and I wish I had done this sooner), I looked at the sensor location with a strong flashlight from behind the axle...ie axle view. Originally there had been so much grime in their,that my first view at it, before starting the job gave me the impression I couldn't see the sensor at all, and it was completely contained within aluminum.... not the case. When I looked this am, all the parts HAD been chipped out, drilled out or whatever, and were lying on the bottom of the hub assembly.... Sheesh. I had scored the edges with the drill bit, but clearly, was actually done already. Few shots of brake cleaner to blast out all the crap...a few shots of PBblaster in the hole, some scraping with a pick, and I pushed in the new one.

I really, really wished I had seen better what was going on from that angle.

Oh well, live and learn. This did restore the ABS/ASC fully too....

[crossfire M3]

PM replied.


I am interested of buying the abs sensors for a 528i e39 1997..

How many sensor does it uses?

In the front, are both the same for left and Right? are they are the same?

In the Rear, are they are the same in each corner?


I would like to know how much it would cost with you guys, Ill be waiting for a response.

[jnyost]

I am interested of buying the abs sensors for a 528i e39 1997..

How many sensor does it uses?

In the front, are both the same for left and Right? are they are the same?

In the Rear, are they are the same in each corner?


I would like to know how much it would cost with you guys, Ill be waiting for a response.

Replied...

[patrickswain]

Hi, My dsc light is on but I dont have any other noticable problems, the cruise control, speedometer and odometer all work perfectly and on top of that there are no other lights that are currently turned on on the car. So im kind of stuck on trying to decide where to start my search for the problem at.

[junkycosmos]

2003 530i / E39
125K MI

Had been doing great till few weeks ago when we received a solid ABS and Traction light that come on immediately after startup before putting car into reverse or drive. Rest of electronics, braking and such all appear fine although ABS and traction control non functional as expected from system fault.


*fluid level (checked,ok)
*fuses (checked,ok)
*speedometer, odometer and cruise control all still work
*wheel sensor tests done today found the following with Ohm meter
(two readings from swapping + & - direction)
left front: 6.49 & 4.17
right front: 6.47 & 4.13
left rear: 6.57 & 4.13
right rear: 6.64 & 4.19

Is there a relay I should check ? If so any idea where ?

Could this be the abs pump itself ? Anyone know if the pump does a self test at startup (should it run at all when the car is 1st started ?)

Are we looking at an abs module rebuild ?

Suggested next steps ?

Thanks for any input.

[e39vinay]

hiii guys...

My speedometer also does not work and strangely...i don't have any light on, on my cluster...i have tested the cluster, all lights work, all wipers work. But my speedometer and MPG calculator does not work. I have disconnected the ABS sensor but only one light comes on, that is the ABS light, the other two remains off. I was told that previous owner of my car has changed my engine from 525d to 525tds and along lots of wirings. I want to know how do i check which wires are wrongly placed cause when we connect the car to check for faults the system does not detect the car...can anyone help me repair m speedometer...can i take a direct connection from speed sensor to my cluster?? please help guysssss...

[junkycosmos]

Just to follow-up on my posting here. My issue turned out to be a bad wire going into the connector which plugged into the driver side front wheel sensor. Translation was that unplugging and checking all sensors passed fine however testing from the ABS plug under the hood to sensor failed.

Many thanks to others who posted reply and also in separate form here. I suggest anyone looking at ABS/Brake Lights do the test from the ABS plug as noted here. Its a lot easier and also tests the wiring harness.

http://www.bimmerfest.com/forums/showpost.php?p=4205801&postcount=48

e39vinay: might test form the ABS plug to rear sensors as noted here since those failures are often a rear sensor.

[e39vinay]

Thanks a lot Junkycosmos, yesterday i tried again disconnecting the ABS module wirings and found their is two lights on; ABS light and the triangle light. But when i connect them again, they goes off. But still no speedometer or MPG wiper working. Upon looking at the ABS Connector i found it different from those one doing test upon, the pins on mine are much thicker while those in the test are thin and of blue colour??... Is it possible that an ABS Module to be incompatible with Cluster and causing no speedometer??...please help guyssss

[gorgio1]

junkycosmos.... so it was the wire going from the wheel speed sensor to your module correct? .... if it was how did you replace it ,,, i think that is whats wrong with mine i dont know yet..
thanks


Just to follow-up on my posting here. My issue turned out to be a bad wire going into the connector which plugged into the driver side front wheel sensor. Translation was that unplugging and checking all sensors passed fine however testing from the ABS plug under the hood to sensor failed.

Many thanks to others who posted reply and also in separate form here. I suggest anyone looking at ABS/Brake Lights do the test from the ABS plug as noted here. Its a lot easier and also tests the wiring harness.

http://www.bimmerfest.com/forums/showpost.php?p=4205801&postcount=48

e39vinay: might test form the ABS plug to rear sensors as noted here since those failures are often a rear sensor.

[junkycosmos]

I lucked out. Apparently the dealer had previously replaced the plug on harness at the wheel side. The key were was unplugging the sensor and then testing from the module side of the sensor plug to the large module plug itself. When I checked I had one wire completely non-conductive / open.

Then I recalled the dealer records prior to our ownership where they had "worked" on this same sensor. When I started following the the harness from the sensor side I found were about 9" up it had been poorly taped and poorly connected with a crimp connector. Removed both, soldered and used a little heat srink tube then taped it backup.

Suggest that you do the testing of the harness by checking OHMS between the large module plug and the individual sensor plug. (using the pin outs noted in the DYI above) Should be near zero resistance.

[gorgio1]

well i would but i dont think the manual above is the same connections for my module because i have the bosch 5.0 module pictured below.

[bagodonuts68]

what if you're not getting any reading on the multimeter. in the diode setting i get a "1" in both directions (swapping red/black). the same happened whether i was taking a reading at the multiconnector by the CPU or at the sensor in the wheel well.

I am guessing it is because the control module is not in the vehicle as it has been sent out to BBA for rebuilding. Does anyone know if you need the control module plugged in to test the wheel speed sensors using a multimeter??

[jnyost]

The reading has nothing to do with the module. You're testing just the sensor. Test another sensor to make sure the test is working properly.

[junkycosmos]

agreed on suggestion of testing another sensor to confirm your test steps and meter are functional

Also keep in mind that testing on the ABS wiring harness plug with when you also have the wheel sensor unplugged too will read as 'open, fault, no loop'. (You need the sensor plugged in to loop back your test.) Sorry if that is too obvious to mention however its an easy miss for first timers on the multi meter.

Another approach would be first to test on the plug of the actual wheel sensor itself (take off wheel and unplug sensor). IF that passes then plug it back into the harness and then retest at the abs module plug. Results should be the same otherwise you have a wire harness issue.

Hope this helps

[bagodonuts68]

to triple check... we are talking about using the setting on the multimeter that looks like an arrow with part of a "+" sign sticking out of it (like
this: >+ ...sort of), right? The meter beeps when i touch the two leads together but only reads "1" when i test any of the speed sensors at the multiconnector. With the sensor plugged in in the wheelwell I have tried both the small square holes (with wires of various gauges, paper clips, etc...) and the slightly larger rectangular holes with one lead in, say, #12 and the other in #28 (or 13/29..., following guidelines by luyckjx). I have tried in the wheel well as well after unplugging the blue connector in the little box and still get a reading of 1.
:help

My traction control and abs went out (lights on dash and much fish tailing but speedo and tach worked fine). I sent the module out and a few days later the check engine light came on. my Peake code reader indicated a speed sensor problem. i have not yet received my module back but i when i do should i hold off on installing it until i am sure the sensors are ok?

i checked my meter on a working diode to determine if its working. got a reading of 1 then switched and got like 1765. I returned again to my silver touring e39 with black interior and tried getting readings at the multiconnector (switched to diode setting) that plugs in to the absent module and reinserted 20 gauge wires in the holes mentioned by luyckxj and got nothing but "1" at both "polarities(?)" (switching black and red leads) for all wheel speed sensors. Maybe a bad idea but i started plugging the wires in other holes off to the other side of the blue multiconnector (toward the higher numbers along rows of holes) and did get some readings for whatever thing those wires went to.

Is it possible that my speed sensors are wired to different holes of the multiconnector? mine is a 2000 e39.

My wires go in about 1/4 inch before hitting a wall of sorts. i have used different gauge wire and tried hard to search for a connection in those holes. suggestions?

This is emasculating... Luckily i was just able to fix a nonopening tailgate AND tailgate window on my wagon or might not have gotten it up last night.

[codeba]

My 528i started acting up with speedometer, traction control, and ABS not working. After reading the posts on this forum, I replaced the left rear speed sensor and that solved the problem. Thanks to the experiences shared through this forum, I probably saved hundred of dollars by DIY!:)

[TribleB]

Hi guys. I just got done replacing one of my ABS/DSC wheel speed sensors on my 540i and thought I'd write about it. I've had two sensors fail over the past two years, and I was able to use the concepts below both times. The actual sensor replacement is trivial; the tricky part is figuring out which sensor failed. I hope that this can help somebody!

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Replacement of Wheel Speed Sensor
E39 BMW

Synopsis: A malfunctioning wheel speed sensor can cause the anti-lock braking and traction control systems to become disabled, among other things.

Symptoms: Three lights appear simultaneously on the dashboard: ABS, an amber BRAKE, and the triangular "traction lost" icon. Traction control is not operational, nor is antilock braking. One or more of the speedometer, odometer, or cruise control might also be inoperable.

Tools required: Multimeter capable of testing diodes. 5 mm Allen wrench. Long, very narrow probes for multimeter, or equivalent. For rear sensors, a 10 mm socket, 8 mm socket, flat-head screwdriver, and needle-nose pliers might be required to remove trim.

Difficulty: Easy

Diagnosis: A BMW service computer can isolate the source of the problem; standard OBDII code readers cannot pull the requisite information. The Peake Research code reader seems to be capable of reporting whether or not a problem exists, but there do not appear to be any codes that reveal the location of the faulty sensor. If a wheel speed sensor is suspected, and no computer is available, the identification process is one of trial and error. Jack up you car and support appropriately. Access to the sensor is considerably easier with the wheel removed, so pick a corner and remove the wheel.

It is worth noting that certain failure modes are associated with particular corners of the car. If the speedometer and odometer do not work, the driver's side rear sensor is probably bad. If the speedometer works but the cruise control does not, then the passenger side rear senor is probably bad.

Locate the sensor (mounted on the wheel carrier near the hub) and trace its wire back to a blue connector. The connector might be housed in a black plastic box. Open the hinged box if it is present. There might be a second connector next to the blue speed sensor connector; that's for the brake pad wear sensor. Pull the blue speed sensor connector out of the box and disconnect the two sides.

Deep inside the sensor side of the connector, there are two metal prongs. Now comes the tricky part. Turn the mutimeter on and to its diode testing setting (it looks like an arrow with a line in front of it). Connect one probe to one of the prongs, and the other probe to the other prong. The meter should read ~1.4-1.8 V or indicate an "open" condition (e.g., "OL"). Reverse the probes. Once again, the meter should indicate either an open condition or a 1.4-1.8 V drop, but the result should be whichever one you didn't see the first time. If you see any other result, such as 600 mV in each direction or 0.0 V in either direction, you've probably found the bad sensor; congratulations! Note that a 0.0 V drop is possibly indicative of a poor test setup; verify that you are not shorting the multimeter probes. If the sensor tests out okay, try again at a different wheel. Of course, it's always possible that one of your speed sensors has failed in a way that wouldn't present itself in this test. In the worst case, you'd have to go to the dealer anyway for the diagnosis.

You might want to try another wheel even if you think you found the bad sensor in order to confirm that your technique is good. It's sometimes a bit tricky to get a good connection to those prongs. If you think you found two bad sensors, you probably messed up.

Be sure to reconnect all of the sensors that you believe are good. Once you have identified the faulty sensor, obtain a replacement BMW part. One sensor on my 540i was $120; I've read reports of them retailing for as little as $70.

Other possible causes: Reports indicate that the cause of the sensor failure might be a frayed wheel-speed sensor wire in the wheel well; inspect the entire visible run of the cable carefully to confirm the lack of frayed or pinched wires. If frayed wires are found, attempt repair using common wire-repair techniques. Other reports indicate that a bad ABS controller might cause similar symptoms.

Replacement: With the wheel off at the corner with the broken sensor, and the sensor cable disconnected, unsnap the sensor wire from the two mount points on the steering knuckle. Follow the cable to the point where it ends at the sensor. The sensor is attached to the car with one or two small bolts. A 5mm Allen wrench is required to remove the bolts. You might have to do this blind, but it's not that hard. After the bolts are removed, gently pull the sensor straight out of its hole. Put the new sensor where the old one was, and reverse the removal process. There were two bolts holding my old front sensor, but the new front sensor included only one mounting hole. Due to the sensor construction, I don't believe it is a problem to use only one bolt. Be sure to hook the new sensor back to the other connector, and don't forget to snap the cable into the cable brackets.

Commentary: I have had two speed sensors fail on my 1999 540i. The first time, a front sensor failed. The DSC, ABS, and brake warning lights were be off when the car was first started but would turn on after driving a couple hundred feet. A year later, a rear sensor failed. The same three lights shone at startup and never reset. The Peake reader indicated code 0F 78. I was able to use the above procedure both times to successfully locate the failed sensor.

---

Jeff

SO my 2001 540 has the three lights on the bake, abs and dsc for a while now so i decide to try and diagnose the problem today my speedometer works but I don't believe my cruise control is working so based on all the previous posting I decided to start at the rear passenger wheel sensor I took out the sensor out of the hub housing and it looked pretty dirty so I cleaned it with electronic cleaner and soft cloth put it back in. I then move up to the blue connector in the box and unplug it to do my diode test this is where I am not so sure my multimeter is set to the stated setting the arrow with line in front but my black wire is in with Com port and my red wire is in the V ohm sign Ma port their is a third port label 10ADC that I tried with the red probe but I didn't get any reading so the reading I got was 918 does this means the sensor is bad when I switch position of the probe I don't get a reading but I was worried that I didn't get ol or open or the 600 reading that was mention above.

[z28forlife]

Are theses speed sensors a common thing that goes out on the e39's? I have a 540i with 170k, I'm starting to debate just to get rid of it before it needs thousands in repair. I'm not sure.

[jamesdc4]

Are theses speed sensors a common thing that goes out on the e39's? I have a 540i with 170k, I'm starting to debate just to get rid of it before it needs thousands in repair. I'm not sure.
Yes. I just replaced all four of mine.
Pics of offending sensor wires...

http://i13.photobucket.com/albums/a282/jamesdc4/IMG-20110728-00076.jpg

http://i13.photobucket.com/albums/a282/jamesdc4/IMG-20110728-00077.jpg

[TribleB]

Can anyone help me decide with my previous post question should I spend between $78-$120 or clean and do a diode test before I start replacing the sensor the wire look to be in ok condition no fraying?

[z28forlife]

I'd clean and test 1st, its free and if it works then your all set. Don't spend the $ unless you have to.

[TribleB]

I also wanted to know if people usually see the lights goes off after replacing or cleaning immediately or do you have to drive the car a few mile to reset it or is there a reset method. ie disconnect the battery.

[TribleB]

So I had some indication today that my sensor might be acting up due to dirt just a guess. I hadn't driven the car since I cleaned the rear passenger side. So I had to make a run from Connecticut to JFK i notice about 8 minutes into my trip the abs and brake lights went off an did so for my entire trip to JFK airport the rest of my morning was a bit more chaotic I almost got tow for leaving the vehicle UN-attended my dad who is 80 and walking with a Kane I had to help to the curbside (not the inside) checkin of Jetblue so I ran back to my car and the tow truck driver lifted my car and would drop it unitl I pay a fee of $55. anyways enough of that the lights came back and stayed on for my entire trip back home my question is I didn't have this grease staburags NBU 12K/ or the equivalent (anyone know the equivalent) I am getting ready to take out the sensor again and use some compress air to blow out some of the dirt and lint I saw is this a good idea all suggestion is greatly appreciated.

[copracr]

My 528i started acting up with speedometer, traction control, and ABS not working. After reading the posts on this forum, I replaced the left rear speed sensor and that solved the problem. Thanks to the experiences shared through this forum, I probably saved hundred of dollars by DIY!:)

I had the same issue on my 99 540i. tested the rear left sensor and it was bad. replaced with a $30 ebay part and has been fine since. about 6 months now.


I also wanted to know if people usually see the lights goes off after replacing or cleaning immediately or do you have to drive the car a few mile to reset it or is there a reset method. ie disconnect the battery.

lights went out by themselves

[Frankie]

....I am getting ready to take out the sensor again and use some compress air to blow out some of the dirt and lint I saw is this a good idea...

In my experience, you're wasting your time.

Unless there's something obviously wrong with the wiring (frayed, torn insulation, etc.), I would suspect your ABS module. Speed sensors are very durable and are not affected by a little dirt.

Go straight to your dealer or indy and get your ABS fault codes diagnosed. I bet the result is: RR wheel speed. You can replace that sensor if you want - I would avoid cheap eBay vendors - but I doubt it'll solve your problem. More likely the module is just not reading that signal due to internal faults. This is what happened to me. And if you're going to attempt sensor replacement first, do not let this happen to you: link (http://forums.bimmerforums.com/forum/showthread.php?t=1694999)

And yes, the lights go off by themselves.

Good Luck!

[cer54467]

Related Query, I have a 2001 M5 and I was wondering if the trie pressure sensors are the same or are they in the wheels? I do nt have any in my car and i would like to get this system working.

[aldbmw]

ataie What ended up being the issue with your service engine light, abs, dsc, and break light all being on? I noticed you replaced all the wheel sensors but at what point did the service engine light go off? I am having the same issue but my goal is to just get that service engine light off first and foremost. Any help would be awesome!!! Thanks

[Hershey]

Okay, I'm still a little confused...
I have a 97 528i with the same issues (trifecta of lights, econometer, speedometer and cruise control not working, ect...) I wanted to check my speed sensors at the ABS plug but mine is so different from the one that I saw in the write-up. Does anyone know what pins to check in my case?

Nevermind....
I found what I was looking for. Unfortunately, it was on another board. However, not wanting others to suffer as I have... If you have an older model e39 (12/95 to 9/98), you can get the pin out for the ABS module here:

http://www.bimmerfest.com/forums/showthread.php?t=487975

This was VERY helpful! Unfortunately, I don't know how to put up pictures on here otherwise I would!

[95m3ltw]

This is a great tip....


My mechanic told me to drill it out, through and through, and use picks and needle nose pliers to pull out the bits... I started the drilling, got tired, and just left it up on the lift. But THIS tip is great, and I'm going to thread in the screw next... great idea.





BTW, on that subject, I was shocked at how affordable a reman PS pump was at the local autozone. $152..... Dealer list was $960 Course, that was for a new one. But even there.... a new ZF from Vines was all of $375. Maybe the dealers are forced to buy via Germany?



Good thing too.... when I re-started today, I took off the calliper, and rotor, and loosened the P-brake pads just enough to allow access tothe dust sheild,and pull out the 4 bolts to that. This allowed a better view "down the hole" and better angles. Still couldn't figure out what was left in there.



This is a good tip for those doing this in the future. If you can't pull the sensor out by hand, I would suggest removing the dust shield first as it will make it MUCH EASIER to see the sensor, drill it and try the screw method. IME, when a sensor is stubborn then the plastic is brittle and there is little hope to remove it except for drilling/picking etc. I changed the RR sensor on our new to us touring last night and the drill/screw method did very little. So I keep increasing the size of the drill bit and then used a pick/small flat blade screw driver to knock the bits out.

I would also add, after doing this till 1 am I should spent about 10 mins trying to get it out with the screw method then moved on to just chipping the sensor out which took less than 30 mins. Be extra careful with the bolt for the sensor and the heat shield bolts, aluminum threads are delicate.

[schtozo]

Got trifecta like 10 days ago, this was after coilovers install and uninstall in a two day period! All three lights turn on after a while of driving, when i turn car off they will go away until i drive a while again. I checked 3 of my sensors by the multimeter so far and they all report 1.4xx, 1.5xx, 1.7xx and such in a direction but the other direction the multimeter doesnt do anything, it just stays at 1. Im testing the sensor side of the plug btw. I still have to test rr sensor. Code 2a appeared which indicates vehicle speed input signal, and today two weeks later, tire control inactive popped up on cluster. Any tips would be great. Thanks

[ninetyseven1]

In my experience, you're wasting your time.

Unless there's something obviously wrong with the wiring (frayed, torn insulation, etc.), I would suspect your ABS module. Speed sensors are very durable and are not affected by a little dirt.

Go straight to your dealer or indy and get your ABS fault codes diagnosed. I bet the result is: RR wheel speed. You can replace that sensor if you want - I would avoid cheap eBay vendors - but I doubt it'll solve your problem. More likely the module is just not reading that signal due to internal faults. This is what happened to me. And if you're going to attempt sensor replacement first, do not let this happen to you: link (http://forums.bimmerforums.com/forum/showthread.php?t=1694999)

And yes, the lights go off by themselves.

Good Luck!

Question for you. I have had a CEL for a while now Speed sensor P0500. I had no speedometer so I replaced rear left sensor and now speedo works, but I have a CEL again, P0500 and a deeper scans reveals front left ABS sensor. Ok, so I replaced it and no more code for that one, but still have a CEL P0500 Speed sensor A ,a deeper scan also reveals rear right ABS sensor ,but my cruise control works fine. is this a bad ASC module?

[Wojtek79]

So I just read the entire thread. I too had the ABS light show up, ASC light lit up, then after coming to a stop at a streetlight and beginning to drive again I noticed that my car was stuck in 2nd gear. Shut if off, looked under the hood for anything odd with no luck. I was able to figure out that as I began driving, if I put the car in 3 and then pushed the stick to D, the trans would shift to next higher gear. Repeating the process I was able to get home as it allowed me to get the trans to operate through all the gears. Car is parked until I can get to take a look at the sensors this weekend. I am just out of theories how the trans shifting may be related to this. Car is a 1997 528i with auto trans and 187k miles.

[ninetyseven1]

So I just read the entire thread. I too had the ABS light show up, ASC light lit up, then after coming to a stop at a streetlight and beginning to drive again I noticed that my car was stuck in 2nd gear. Shut if off, looked under the hood for anything odd with no luck. I was able to figure out that as I began driving, if I put the car in 3 and then pushed the stick to D, the trans would shift to next higher gear. Repeating the process I was able to get home as it allowed me to get the trans to operate through all the gears. Car is parked until I can get to take a look at the sensors this weekend. I am just out of theories how the trans shifting may be related to this. Car is a 1997 528i with auto trans and 187k miles.

Scan the car or get it scanned. Sounds like what happened to my car last summer, Not sure about being stuck in 2nd gear but I couldnt go over 30 mph, I disconnected the cable from the ASC throttle actuator that goes to my throttle body and the problem went away. I suspect a bad ASC module. The ASC module in my 97 540i will close the throttle when it get a message about the wheels losing traction, and my ASC module must have been acting up and it was thinking I was losing traction.

[Wojtek79]

Does anyone have a part number for these ABS/Speed sensors? I dug through REALOEM under transmission, brakes, electrical and I must be going blind.

[Flounderasu]

Does anyone have a part number for these ABS/Speed sensors? I dug through REALOEM under transmission, brakes, electrical and I must be going blind.

It's under the Front and rear axle assy's

http://www.realoem.com/bmw/showparts.do?model=DN53&mospid=47588&btnr=31_0255&hg=31&fg=10
http://www.realoem.com/bmw/showparts.do?model=DN53&mospid=47588&btnr=33_0519&hg=33&fg=30

[ninetyseven1]

Im going to replace the rear right speed sensor and hopefully the light goes away! If not it has to be an ASC module gone bad. I also, have a traction control light stuck on.

[Wojtek79]

It's under the Front and rear axle assy's

http://www.realoem.com/bmw/showparts.do?model=DN53&mospid=47588&btnr=31_0255&hg=31&fg=10
http://www.realoem.com/bmw/showparts.do?model=DN53&mospid=47588&btnr=33_0519&hg=33&fg=30

Thank you a million. I just wanted to confirm if this was an E39 specific part or can I grab one from an E38. I would much rather get a used OEM part compared to a new aftermarket. I will post an update once I dig into this. Hopefully tomorrow

[flyingfed]

My 1997 528i is doing exactly what yours did. ASC and ABS lights only came on. Everything works, speedo, cruise control, etc. Only thing wrong is having to shift gears from 2nd to third to fourth manually in sport mode. What was your solution?

[Wojtek79]

Just to put an update to my post... I replaced the sensors with a set pulled from a salvage car. No problems since.

[mfan225]

If you prefer it in video format, I found this:

http://youtu.be/uw8NKDOupnk

[flyingfed]

Thanks Wojtek79, did you replace all 4?

[Wojtek79]

Definately the front two and i think one in rear. I do not remember. Its been a while

[Jasbaby5]

Im having the same problem on my e39 ASC And ABS lights are on , i changed all fout speed sensors , now my speedometer stopped working .. WTF ? What could it be ? Help please

[mfan225]

Im having the same problem on my e39 ASC And ABS lights are on , i changed all fout speed sensors , now my speedometer stopped working .. WTF ? What could it be ? Help please

Abs module more than likely. Needs to be rebuilt.

[BMW540san]

- - - Updated - - -


Im having the same problem on my e39 ASC And ABS lights are on , i changed all fout speed sensors , now my speedometer stopped working .. WTF ? What could it be ? Help please
Yes, it's old thread revived, but anyway:
If you replace all 4 sensors and speedometer stops working right after install, it probably means you installed cheap aftermarket sensors and they're the cause, not the module.
OEM BMW or VDO Siemens sensors, anything else and you just might regret it.
I put VDO Siemens on both of my 5's and no issues.

[joshs540i]

I just want to share my experience with aftermarket sensors, to hopefully save someone the same trouble I had. I ended up with two DOA sensor before I found a working one. part #34521182159 for 98 540i front wheel.
The two DOA sensors i received seemed to be identical (packaging and all) although they were from different sellers and one from Amazon (Performance Parts Network) and one from eBay(prime_auto). they both metered out open but I installed them to be sure. no go.
The good part i purchased from eBay seller SanlongParts 574166 The easiest way to identify the working sensor is by the square second rib on the connect (circled in the attached photos).574167
Maybe I was unlucky with the first two or lucky with the third, but hopefully this will save somebody some trouble who wants to save $100+ per sensor vs oem.

[Pargac880]

I've replaced all my speed sensors and my abs and brake lights are on and sometimes my speedometer works. What else can it be? I have 2001 BMW 530i

[Mcdiver]

I've replaced all my speed sensors and my abs and brake lights are on and sometimes my speedometer works. What else can it be? I have 2001 BMW 530i
Did you replace them with BMW sensors? If not, you may have gotten bad sensor or two.

[SadE39]

I am appreciative. I will be checking the wiring and either repairing if ordering a front right wheel speed sensor. You were tremendously helpful.

- - - Updated - - -

I've read about the ABS control unit dying. Which sounds pretty obnoxious. Some have said that produces false wheel speed sensor errors and intermittent symptoms. Here is a detailed write up: http://www.bimmerfest.com/forums/showpost.php?p=4205801&postcount=48

- - - Updated - - -

I will look closely at sensor pics when ordering. Thank you.

[platinum911]

Hi guys. I just got done replacing one of my ABS/DSC wheel speed sensors on my 540i and thought I'd write about it. I've had two sensors fail over the past two years, and I was able to use the concepts below both times. The actual sensor replacement is trivial; the tricky part is figuring out which sensor failed. I hope that this can help somebody!

----

Replacement of Wheel Speed Sensor
E39 BMW

Synopsis: A malfunctioning wheel speed sensor can cause the anti-lock braking and traction control systems to become disabled, among other things.

Symptoms: Three lights appear simultaneously on the dashboard: ABS, an amber BRAKE, and the triangular "traction lost" icon. Traction control is not operational, nor is antilock braking. One or more of the speedometer, odometer, or cruise control might also be inoperable.

Tools required: Multimeter capable of testing diodes. 5 mm Allen wrench. Long, very narrow probes for multimeter, or equivalent. For rear sensors, a 10 mm socket, 8 mm socket, flat-head screwdriver, and needle-nose pliers might be required to remove trim.

Difficulty: Easy

Diagnosis: A BMW service computer can isolate the source of the problem; standard OBDII code readers cannot pull the requisite information. The Peake Research code reader seems to be capable of reporting whether or not a problem exists, but there do not appear to be any codes that reveal the location of the faulty sensor. If a wheel speed sensor is suspected, and no computer is available, the identification process is one of trial and error. Jack up you car and support appropriately. Access to the sensor is considerably easier with the wheel removed, so pick a corner and remove the wheel.

It is worth noting that certain failure modes are associated with particular corners of the car. If the speedometer and odometer do not work, the driver's side rear sensor is probably bad. If the speedometer works but the cruise control does not, then the passenger side rear senor is probably bad.

Locate the sensor (mounted on the wheel carrier near the hub) and trace its wire back to a blue connector. The connector might be housed in a black plastic box. Open the hinged box if it is present. There might be a second connector next to the blue speed sensor connector; that's for the brake pad wear sensor. Pull the blue speed sensor connector out of the box and disconnect the two sides.

Deep inside the sensor side of the connector, there are two metal prongs. Now comes the tricky part. Turn the mutimeter on and to its diode testing setting (it looks like an arrow with a line in front of it). Connect one probe to one of the prongs, and the other probe to the other prong. The meter should read ~1.4-1.8 V or indicate an "open" condition (e.g., "OL"). Reverse the probes. Once again, the meter should indicate either an open condition or a 1.4-1.8 V drop, but the result should be whichever one you didn't see the first time. If you see any other result, such as 600 mV in each direction or 0.0 V in either direction, you've probably found the bad sensor; congratulations! Note that a 0.0 V drop is possibly indicative of a poor test setup; verify that you are not shorting the multimeter probes. If the sensor tests out okay, try again at a different wheel. Of course, it's always possible that one of your speed sensors has failed in a way that wouldn't present itself in this test. In the worst case, you'd have to go to the dealer anyway for the diagnosis.

You might want to try another wheel even if you think you found the bad sensor in order to confirm that your technique is good. It's sometimes a bit tricky to get a good connection to those prongs. If you think you found two bad sensors, you probably messed up.

Be sure to reconnect all of the sensors that you believe are good. Once you have identified the faulty sensor, obtain a replacement BMW part. One sensor on my 540i was $120; I've read reports of them retailing for as little as $70.

Other possible causes: Reports indicate that the cause of the sensor failure might be a frayed wheel-speed sensor wire in the wheel well; inspect the entire visible run of the cable carefully to confirm the lack of frayed or pinched wires. If frayed wires are found, attempt repair using common wire-repair techniques. Other reports indicate that a bad ABS controller might cause similar symptoms.

Replacement: With the wheel off at the corner with the broken sensor, and the sensor cable disconnected, unsnap the sensor wire from the two mount points on the steering knuckle. Follow the cable to the point where it ends at the sensor. The sensor is attached to the car with one or two small bolts. A 5mm Allen wrench is required to remove the bolts. You might have to do this blind, but it's not that hard. After the bolts are removed, gently pull the sensor straight out of its hole. Put the new sensor where the old one was, and reverse the removal process. There were two bolts holding my old front sensor, but the new front sensor included only one mounting hole. Due to the sensor construction, I don't believe it is a problem to use only one bolt. Be sure to hook the new sensor back to the other connector, and don't forget to snap the cable into the cable brackets.

Commentary: I have had two speed sensors fail on my 1999 540i. The first time, a front sensor failed. The DSC, ABS, and brake warning lights were be off when the car was first started but would turn on after driving a couple hundred feet. A year later, a rear sensor failed. The same three lights shone at startup and never reset. The Peake reader indicated code 0F 78. I was able to use the above procedure both times to successfully locate the failed sensor.

---

Jeff


I know this thread is ancient, but having an issue with abs and traction control light going off. Basically shifting manually right now. Hooked up INPA stated front right sensor. I opened it up and a wire from the sensor was broken.

I ordered a new sensor and did the diode test, and the meter shows 1824 for a split second than back to zero. Flipping the connection doesn't show anything.

With new sensor the abs and traction control light come back when going over 5mph.

Connection from the car harness shows roughly 680 regardless of how you flip the connection on the meter.

Question is, is the meter suppose to stay at 1824 or only show it on initial contact than back to zero, or is this sensor not working properly?

[mfan225]

What brand sensor did you buy? I don't have my E39 right now otherwise I'd definitely take a look for you...


Sent from my iPhone using Tapatalk

[platinum911]

It's a cheap one I purchased, not OEM or Bosch. Just want to know if it is behaving correctly

[Wojtek79]

It's a cheap one I purchased, not OEM or Bosch. Just want to know if it is behaving correctly

I recall reading the same problems about generic sensors.

[jp5Touring]

I had the trifecta on my winter wagon. I read the generic sensors suck so I purchased a oem one through FCPEuro. Half hour later all my codes were gone.
$60. done

[JackGrimSinn]

I've had a lot of abs problems with my car and I want to remove it. I already drive with the wire to the abs module disconnected,
Can anyone tell me what to do to completely rid my BMW of abs,
I seen on google that fuse F30 goes to the abs, if I take that Fuse off, will it stop my car from activating any abs at all?
I also read in the owners Manuel that the abs is integrated with the wheel bearing, but if I rip off or remove the wire to the abs behind the wheel will that also ensure it from NOT working?
My speedometer gave out one day too and even though I'm removing abs is it possible to keep the speedometer working or will I have to convert it somehow or find a different metthod of hacking it????
Please help, I don't know much about cars but I've been learning with my E39- Brakes, Rotors, Hand Brake, projector lights, water pump, belts, oil housing gasket, transmition replacing, starter, fuel pump, head gasket, spark plugs, ignition, the list goes on and YouTube doesn't have a video for everything either :(
I can get the tools from my uncle but he doesn't have enough time to help me learn about my car, and I don't have enough money to be buying parts and lessons from him :(

[Eurus39]

2000 e39 540i abs comes on low speed. Drivers side front . NO codes or indicators. Changed wheel speed sensor , no improvement...........read a couple of threads around, one suggested corrosion under the sensor. sounded like BS to me , removed sensor plugged the sensor hole so no debris could enter . Used 80 grit to clean around under mounting area. I also filed down the flanges on the sensor so the sensor would protrude a lil further towards the reluctor wheel. This seems to have done the trick ,no more abs pulsing at low speed or any speeds......................Tom