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Teuobk
02-28-2007, 10:19 PM
Hi guys. I posted this write-up in a separate thread, and several people suggested that I replicate it here. Between the time I first posted it (9/06) and now, I've used the procedure yet again to locate a failed speed sensor. For those keeping score, that means I've replaced three of the four sensors on my 540i in the past two years.

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 three 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. A few months after that, I had another rear sensor fail. I was able to use the above procedure all three times to successfully locate the failed sensor.

---

Jeff
____________________________
Edit: Here is a DIY with pics from M5board.com.
http://www.m5board.com/vbulletin/e39...front-diy.html

jamesdc4

herc97
04-26-2008, 11:41 PM
i have that triangler light come on when i first start my car up . then i drive to work, park and then come down stairs and start it back up and the light goes off i think this is helpful i will check these sensors!

koko164
05-04-2008, 07:41 AM
Does anyone know where I can obtain the male end of the blue connector on the Wheel Speed Sensor cable?:help Mine have all started to crumble away and i note they are easy to remove but can't find anywhere that I can obtain new ones.

wintersm
08-18-2008, 06:10 PM
Jeff,

Thanks for the post. It sounds like you've replaced enough of these to know what you're doing. Maybe you know what I'm doing wrong? When I test the sensor with diode test on my multi-meter, I get either a steady "1" or if I reverse the direction I get a jump to just under 2000, then back down to 1 (very fast). If I test the resistance in either direction I get the same value of 160,000 Ohms (give or take). This happens for all 4 sensors and I still get the standard BRAKE, ABS, and DSC indicators illuminated after a few miles of driving.

Any suggestions?

gtxragtop
08-18-2008, 08:46 PM
The sensors I suspect are hall effect sensors. They generate a voltage pulse when the wheel is spun. Hence you want to measure millivolts not ohms. The faster you spin the wheel, the more voltage it will generate. Ideally, you look at the pulses with an oscilloscope since this will give a very accurate look at what the sensor is doing.




Jeff,

Thanks for the post. It sounds like you've replaced enough of these to know what you're doing. Maybe you know what I'm doing wrong? When I test the sensor with diode test on my multi-meter, I get either a steady "1" or if I reverse the direction I get a jump to just under 2000, then back down to 1 (very fast). If I test the resistance in either direction I get the same value of 160,000 Ohms (give or take). This happens for all 4 sensors and I still get the standard BRAKE, ABS, and DSC indicators illuminated after a few miles of driving.

Any suggestions?

knux11
08-19-2008, 11:57 AM
old thread, but should help me in the near future. thanks!!

VasceBimmer
09-07-2008, 12:45 PM
I need some assistance here. The dealer showed me the code printouts. It says front left speed sensor. Now... The tech told me to change the speed sensor and the ASC module because the faulty sensors generally cause the modules to fail also. I'm not sure if I'm buying that advice. I want to change the speed sensor. Will I need to reset the fault or will it correct itself after the replacement? I would like to know because I do not have a computer.

knux11
09-07-2008, 01:46 PM
it will resolve itself. just change the sensor, it's real easy and it's an 80 dollar part. More thru stealer. but replacing the asc module is a waste of money at this point.

VasceBimmer
09-08-2008, 03:25 PM
Awesome! Thanks. Let's see how it goes.

blackraven15205
03-04-2010, 10:13 PM
Thank you again as many have for this. You saved me lots of time and tons of money. My speedometer was out in my '01 530i and needed it to pass inspection, $23! on Ebay for a brand new direct fit OEM aftermarket sensor. Followed the details, and worked perfect!

mikejbmw
03-07-2010, 04:56 PM
Early '97 540i

Anyone else try the cheap ABS sensors? I assume this is a Chinese part, do they work, any longevity here?

tru350z
04-20-2010, 01:30 PM
Thank you very much for useful information.

I have tried to take the rear sensor out but plastic peice broke.
Is it ok to drill out the hole? Is it open end from the hub?

gjp111
06-24-2010, 10:32 AM
Please provide any information that may help.
My speedometer and vacum gagues as well as my odometer are intermittent. If the car sits for a day or so thay will work fine for about 5 or 10 minutes then out for the rest of the day. The ABS & DSC lights never light not even when I first turn on the key any check all other lights. I believe the wheel sensors are ok but not sure because of the intermittent problem. Does anyone have any suggestions for me? Is it possible the sensor box in the console is bad? Or the abs unit? I would think either would produce a constant ABS DSC light but I have no lights ever.

jregier
07-26-2010, 11:33 AM
Hey Guys... My DSC light comes on only when i turn right at speed. When i'm going slow and making right hand turns in town, nothing happens but when i am on the hiway and take an off ramp or slightly more aggressive right hand curve the light comes on, the engine cuts power and the cruise cuts out. After i straighten up the light goes off and i'm able to accelerate again. this must be a speed sensor but any clues to narrow it down?

thanks

Teleplayer
07-26-2010, 01:22 PM
Hey Guys... My DSC light comes on only when i turn right at speed. When i'm going slow and making right hand turns in town, nothing happens but when i am on the hiway and take an off ramp or slightly more aggressive right hand curve the light comes on, the engine cuts power and the cruise cuts out. After i straighten up the light goes off and i'm able to accelerate again. this must be a speed sensor but any clues to narrow it down?

thanks
If cruise control turns off, I think you may want to check the passenger side rear sensor:

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.
Mine's a 98 528i, and all but one sensor was bad. It was obvious, too.. once I looked under the car. If you jack it up and remove the tire, you should be able to follow it from the sensor to the connector... it's possible that you will see that it is frayed, but you may need to use a multimeter to make sure.

Steve

anacondatcu
07-30-2010, 04:12 PM
Hey Guys... My DSC light comes on only when i turn right at speed. When i'm going slow and making right hand turns in town, nothing happens but when i am on the hiway and take an off ramp or slightly more aggressive right hand curve the light comes on, the engine cuts power and the cruise cuts out. After i straighten up the light goes off and i'm able to accelerate again. this must be a speed sensor but any clues to narrow it down?

thanks

i'm experiencing a similar cut in power but it happens sometimes trying to accelerate normally, turning on the DSC light until i release the gas for a few seconds, it also turns off the cruise until i restart the car. Please let me know if you do anything to further diagnose the wheel speed sensors

postkent
08-05-2010, 09:55 PM
my windshield wiper dont work when i pull the handle in ,one speed work but i have to hold it

oh its a 1999 528i

kopka
08-29-2010, 12:09 PM
Hi guys. I posted this write-up in a separate thread, and several people suggested that I replicate it here. Between the time I first posted it (9/06) and now, I've used the procedure yet again to locate a failed speed sensor. For those keeping score, that means I've replaced three of the four sensors on my 540i in the past two years.

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 three 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. A few months after that, I had another rear sensor fail. I was able to use the above procedure all three times to successfully locate the failed sensor.

---

Jeff
____________________________
Edit: Here is a DIY with pics from M5board.com.
http://www.m5board.com/vbulletin/e39...front-diy.html

jamesdc4


Jeff,
This helped me on my 1987 325. Left front wheel speed sensor wires were broke (inside insulation) at the strain relief (bracket on shock). Stirpped wires, soldered & covered with heat strink tubing. Good as new. Thanks for the tips.

Jeff

dinot71
08-30-2010, 10:07 AM
Can someone please tell me how many Speed sensors a E39 5-Series has? Is there one in each corner or just where the pas wearing sensors are located?

email: dinot71@gmail.com

dinot71
08-31-2010, 12:36 PM
How many ABS speed sensors does the E39 have? 4? 2?

repandpresent
08-31-2010, 01:06 PM
4

dinot71
12-15-2010, 03:06 PM
Are there any tricks on removing the rear ABS sensor, I can see its easy to remove it from the caliper but how about the other end? It looks like is wedged up in there.

bagodonuts68
02-15-2011, 01:04 PM
thanks to jeff for the original post outlining the steps to diagnose wheel speed sensor issues in the e39. Following his directions my multimeter in the diode setting reads 1 regardless of polarity and regardless of where i check (at multiconnector under the hood or at the sensor in the wheel well....hmph).

does the control module need to be present to check wheel speed sensors? My module is out to get fixed at BBA. i want to make sure the sensors are good before i plug the rebuilt module back in. I am thinking it needs to be plugged in to get a reading. if so, am i at risk of damaging the module again by installing it into the car with a bad wheel speed sensor??

Longshot512
11-18-2011, 02:17 AM
Thanks for the write up! I have that exact issue and was trying to figure out where to start troubleshooting. For anyone else out there that has those lights poppin' up and wants to replace the sensor: check out the link I added, pretty cheap prices on there.

http://www.usedpartslive.com/catalog/?N=4294964619&Nr=OR%28AND%28make:BMW,model:525i,year:2001%29,AND %28universal:1%29%29&Vi=9732+4294963742+1580&y=2001&mk=BMW&md=525i

MKpoto
11-18-2011, 02:44 PM
great write up, I have this same issue but never really minded it

tystick999
12-13-2012, 07:34 AM
I have a 1999 528i, and my symptoms were as follows:
When cold, I would start and drive the car, and usually within 5 minutes, the ABS Yellow Warning Triangle would appear on the dash, followed shortly thereafter by the odometer/mpg guages not working. I jacked up the drivers side rear of my 528, removed the wheel, and just inside the brake housing tword the front of the car is where the Wheel Speed Sensor attaches to the brake assembly. I removed the allen head bolt holding it in place, and gently pulled the business end of the sensor out. IT WAS CAKED WITH DIRT, GRIME, AND DUST. I simply cleaned the end with Carb Cleaner, and reinstalled. IT LITERALLY TOOK ME 10 MINUTES. I got in this morning, drove for 10 miles, and NO MORE WARNING LIGHTS and my Odometer works like a Champ-Pee-On. The end of the Wheel Speed Sensor is a magnetic device, and interference was created when it was caked with crud. BEFORE YOU BUY A PART, try it. EASY, EASY, EASY.

David X5
12-19-2013, 09:17 PM
I'm having similar trouble with the warning lights E53 X5 (2001 4.4). The speedo still works, but the traction control and DSC lights come on after I drive a short distance. I found wires broken off at the car-side of the connector of the front left sensor. The plastic connectors are available from the dealer and the parts guy gave me a tip that you can buy the sockets that fit inside (they are seperate) pre-crimped with 18" lengths of wire. So, getting the socket is easy.
I even bought a replacement black plastic box to protect the connector in the future.

I have a question about the sensor - it is the 2-wire front sensor. The existing wires broke off at the connector so I have no visual clues to help with polarity to connect the replacement - does the polarity matter? How can I figure out which wire goes where?

Thanks,

David

francischris
12-20-2013, 10:01 PM
I just bought a 1998 540i with 11000 and am wondering if the timing chain needs changing?

dellthecomputer
03-28-2014, 04:36 PM
way l would do it if the car is old and with miles, just cut to the chase
and replace them all then see what happens. it is nice to know that
you can check them all, one at a time to see which one is bad but why
chase the mouse when you can hammer'im over the head with just one
blow-- replace them all with an elderly car. lf the car was new, l can
see just checking to see which one is bad...... just a thought




I need some assistance here. The dealer showed me the code printouts. It says front left speed sensor. Now... The tech told me to change the speed sensor and the ASC module because the faulty sensors generally cause the modules to fail also. I'm not sure if I'm buying that advice. I want to change the speed sensor. Will I need to reset the fault or will it correct itself after the replacement? I would like to know because I do not have a computer.

EURO E39
03-31-2014, 03:50 AM
Does a bad speed sensor trick the MAF/transmisison into staying in low gear up to 3k before shifting?
I have a roaring sound up front , like bad hub bearings when I turn left/right....impacting the hall sensors?
Read somewhere this was realted to low voltage on battery maybe even.
Appreciate your assistance. Thankyou! bimmermtg@yahoo.com

easymoney
04-09-2014, 11:41 PM
I would say yes because my E39 sedan will not shift (I would manually shift to S3 then back to D) but after replacing the front sensors just yesterday it's shifting normally now.

ovanegas
05-04-2014, 01:36 AM
I would say yes because my E39 sedan will not shift (I would manually shift to S3 then back to D) but after replacing the front sensors just yesterday it's shifting normally now.
My 97 e39 is shifting ok after replacing the front speed sensor but the lights are still on
what do I need to do?

hockeyplayer
09-12-2014, 06:31 PM
Can I drive my 2000 323ci while the Speed Sensors are removed? I am going to try cleaning them up good =before ordering new ones! ALSO... whats the best way to clean them? Ive tried searching this with no luck. but also I have just joined this forum so im new. THANSK TO ANY HELP!!! and I know this thread is dead since 2011 but any help is much appreciated!!!

bmxben14
09-15-2014, 06:06 PM
Ok this is getting annoying.. Got my codes scanned. Codes that came up..

FR sensor implasable
RR sensor fail
Error to communicate with egs

So I replaced FR.
RR sensor is good(tests good and works on the other wheel) but noticed my abs ring the wheel bearing had a rust hole. So I replaced the wheel bearing hoping that was the issue. Nope, still get codes for RR sensor failure. ?? Wires all look and perform fine.

And the egs(gearbox). What's up with that? I have a manual.

Anyone have a familiar issue??

Black540Msport
10-06-2014, 10:59 AM
Here's my writeup with pics. Should go nicely with your technical side of the issue writeup. http://forums.bimmerforums.com/forum/showthread.php?1812637-DIY-ABS-Brake-DSC-Speedo-not-working-gas-gauge-wacky-MPG-not-working

Cracker
11-14-2014, 09:32 PM
Just go to the dealer and be done. I tried the cheap ebay $40 sensor and did not work. You can see the hall sensor was not set perfectly centered vs. the OE on the bottom. After backing down the driveway and about 100 feet the lights went out and car shifted perfectly.

http://i14.photobucket.com/albums/a317/jasonrj217/1998%20BMW%20528i/IMG_0011_zpseada3d07.jpg

f10_M550i
01-06-2015, 05:11 PM
Hi guys. I posted this write-up in a separate thread, and several people suggested that I replicate it here. Between the time I first posted it (9/06) and now, I've used the procedure yet again to locate a failed speed sensor. For those keeping score, that means I've replaced three of the four sensors on my 540i in the past two years.

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 three 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. A few months after that, I had another rear sensor fail. I was able to use the above procedure all three times to successfully locate the failed sensor.

---

Jeff
____________________________
Edit: Here is a DIY with pics from M5board.com.
http://www.m5board.com/vbulletin/e39...front-diy.html

jamesdc4

I would just add that as part of the procedure by the OP, to spray Brake cleaner inside the holes where the sensor's plug-in, whilst turning the wheel several turns with your hand. Spray it really good! The sensor reads metal splines has they pass by the sensor. The splines get filled with brake-pad dust (partly due to magnetism) which leads to the sensor failing to properly read the wheel speed and contributes to the failure.

busyphil365
03-16-2015, 05:40 PM
hey guys need some help please. 1997 528i automatic. I recently replaced the drivers rear wheel bearing & sensor. now speedometer no longer works. Car shifts and drives fine, no limp mode or anything of that nature. My first thought was that the elcheapo wheel bearing I used wasn't working with the sensor to send signal to the speedometer so tried swapping the sensor back to the old sensor that was on the car before, still no speedometer.... So fine that's what I get for trying to go the cheap route, I ordered and installed another new (OEM fag) wheel bearing and still no speedometer. tried swapping the sensors around from the old to the new one, then another new one ect.. still no speedometer.. What am I missing here.. shouldn't be this difficult... Thanks

busyphil365
03-20-2015, 06:28 PM
hey guys need some help please. 1997 528i automatic. I recently replaced the drivers rear wheel bearing & sensor. now speedometer no longer works. Car shifts and drives fine, no limp mode or anything of that nature. My first thought was that the elcheapo wheel bearing I used wasn't working with the sensor to send signal to the speedometer so tried swapping the sensor back to the old sensor that was on the car before, still no speedometer.... So fine that's what I get for trying to go the cheap route, I ordered and installed another new (OEM fag) wheel bearing and still no speedometer. tried swapping the sensors around from the old to the new one, then another new one ect.. still no speedometer.. What am I missing here.. shouldn't be this difficult... Thanks


Anyone have any thots on this?

Cracker
03-20-2015, 08:11 PM
Anyone have any thots on this?
Sounds like you should swing into your mechanic and ask them to hook up the laptop and see what the speed sensors are doing.

busyphil365
03-22-2015, 06:19 AM
I've got a diagnostics reader that I use. Problem is somehow between the wheel bearing and the abs sensor on the back drivers wheel isn't sending or creating the signal. . Why it's not is the problem. Worked fine before the wheel bearing was changed. Then didn't with the cheap wheel bearing. Replaced bearing again with ( fag ) bearing and have tried 3 different abs sensors to no avail...

dlucke17
05-05-2015, 12:14 PM
Guys,

tried to fix this on my dad's 98 528i. My question is, should I need to go have the codes cleared after replacing the sensor or should this change work on the fly? I replaced the F drivers sensor (usual issues, ASC / ABS lights on, tranny does not shift) yesterday but the car still acts as if it is faulty. The male part of the clip broke while I was removing it from the old sensor but I was able to fit it back into the new clip. I am searching for that part number now, but if anyone has it handy, that would help.

Other thoughts?

Simon528i
05-07-2015, 04:36 PM
Guys,

tried to fix this on my dad's 98 528i. My question is, should I need to go have the codes cleared after replacing the sensor or should this change work on the fly? I replaced the F drivers sensor (usual issues, ASC / ABS lights on, tranny does not shift) yesterday but the car still acts as if it is faulty. The male part of the clip broke while I was removing it from the old sensor but I was able to fit it back into the new clip. I am searching for that part number now, but if anyone has it handy, that would help.

Other thoughts?
I have this exact problem on my 98 with the abs and acs light, tranny wont shift, how do i fix this?

busyphil365
05-15-2015, 08:32 AM
I'm not sure either. I still haven't been able to resolve this issue yet. I've got a creator c310 scanner that pulls the info for all the systems for the diagnostics no codes stored for trans or abs but still no speedometer... I don't get it.

Black Magic
05-15-2015, 05:44 PM
The trans won't shift properly if it does not get a signal from the wheel speed sensors that is plausible. Trans needs to know how fast the wheels are spinning. You'll have to find the bad sensor or replace them all. I went through this 2 years ago and ended up with all 4 new sensors and now they are acting up again. Have no trouble unless its rainy and we drive on wet roads. Water must get in somewhere and mess with the speed sensor signals. 2 years ago my sensors were disintegrating and bare wires exposed. Now these are quite new so I do not know why they would fail. Car is a '97 528i. I get the triangle light, the ABS light and the trans won't shift properly but I can get it to shift by manually going to 3 then back to D.

b2ke
05-16-2015, 02:18 PM
How do I get out a speed sensor that has rusted into the wheel well and is broken? Long drill?

300kplus
08-01-2016, 11:42 AM
Hi Jeff, great write up from some years ago. I just replaced the driver's side rear wheel speed sensor after being told some time ago it was throwing a code by my then mechanic. Unfortunately, I could not pull it apart at the connector end which should have beed a simple (maybe) pull out, snap in the new one and wala!--somebody had used some kind of sealant and it needed to be cut and spliced...
This brings up a few questions and concerns; Is that going to affect it's performance? Will it even work if spliced?
Also how many miles or how fast, (or a combination of what things do I need to do before I know if it works or not? Does the trifecta disappear immediately? Over time? Please give the series of events that has to happen before I have to start all over again please.
Thanks.

Cora540
08-01-2016, 02:54 PM
Hi Jeff, great write up from some years ago. I just replaced the driver's side rear wheel speed sensor after being told some time ago it was throwing a code by my then mechanic. Unfortunately, I could not pull it apart at the connector end which should have beed a simple (maybe) pull out, snap in the new one and wala!--somebody had used some kind of sealant and it needed to be cut and spliced...
This brings up a few questions and concerns; Is that going to affect it's performance? Will it even work if spliced?
Also how many miles or how fast, (or a combination of what things do I need to do before I know if it works or not? Does the trifecta disappear immediately? Over time? Please give the series of events that has to happen before I have to start all over again please.
Thanks.
The speed sensors should have 0 effect on performance, if your car isn't performing like it should than its not the speed sensors. The trifecta will disappear if it is indeed the speed sensors that needed to be replaced. From what i've read, you need to replace them with OEM sensors. The ebay ones do not work...odds are if it doesnt fix your trifecta than you need to have your ABS module replaced/repaired which can be done by sending your ABS unit to get repaired or buying a new one (which will cost much more)

300kplus
08-02-2016, 02:47 PM
The speed sensors should have 0 effect on performance, if your car isn't performing like it should than its not the speed sensors. The trifecta will disappear if it is indeed the speed sensors that needed to be replaced. From what i've read, you need to replace them with OEM sensors. The ebay ones do not work...odds are if it doesnt fix your trifecta than you need to have your ABS module replaced/repaired which can be done by sending your ABS unit to get repaired or buying a new one (which will cost much more)

Thanks for this, but, in performance I meant by splicing the wheel speed sensor will it still work? Has anybody ever done this?
I've heard conflicting stories about whether to use OEM or not-some people have apparently had luck with aftermarket but I'll cross that bridge when I get to it. Right now I just need to figure out if it's going to work or should have worked already. Given that spliced it...

Cora540
08-02-2016, 03:39 PM
Thanks for this, but, in performance I meant by splicing the wheel speed sensor will it still work? Has anybody ever done this?
I've heard conflicting stories about whether to use OEM or not-some people have apparently had luck with aftermarket but I'll cross that bridge when I get to it. Right now I just need to figure out if it's going to work or should have worked already. Given that spliced it...
Are all of your gauges in your cluster working? What about cruise control?

300kplus
08-05-2016, 10:00 AM
Are all of your gauges in your cluster working? What about cruise control?

No. Are they (excluding cruise control) suppose to turn off right away?

300kplus
08-06-2016, 01:46 PM
No. Are they (excluding cruise control) suppose to turn off right away?

Anyone??

inggalaxia
09-07-2016, 10:11 PM
i have a question what about the front sensors can those be faulty and what the usage of it because i hear about rear but not front mine is a 1999 528i

RAE 1
08-28-2017, 08:50 AM
Good day all, I'm new on the form and I own my 1st BMW and it just happens to be a E39 523T I love the car but I seem to have that same 3 finger salute, only thing is yes my speedo does not work and I have the 3 lights on but early morning with start up the speedo does work and the car runs with no problems, I then travel 20KM to work with no problems, as soon as I hit traffic the car goes into limp mode and I'm left with only 3rd gear. I'm a sales rep so I'm on the road most of the time in the city the car stays in limp mode but as soon as I'm on a open road and I'm doing a constant speed the speedo comes back into play when this happens I stop the car switch of and remove the key I wait 10 seconds and when I start up I have normal drive again and no more limp mode up until I have to slow down again. Could this be a dirty speed sensor or a faulty one? I'm in South Africa and parts are crazy expensive here. Please help! Thanks.

Black Magic
08-28-2017, 03:18 PM
Could this be a dirty speed sensor or a faulty one?

The answer is yes it could be a dirty or faulty speed sensor. Take the wheels off and look at the sensor wires and if any of the insulation is cracked or bare wire exposed replace the sensors. These are very sensitive to aging and they all fail eventually. If yours have never been done just replace all 4 of them. I had trouble buying a recognized German brand and they did not work in the rear. Had to replace them with BMW parts at more than twice the price. The funny thing is that the replacements appeared exactly the same as the original ones yet they would not work. You can save some cash by purchasing them in the US from FCPeuro.com. They offer lifetime warranty as well. Good luck.

RAE 1
09-04-2017, 02:41 AM
Thanks, I will remove the wheels this week and check all the wires. I will keep you all up to date with the progress. Happy miles to all!

Rumzdizzle
09-05-2017, 02:24 PM
Great write up! You guys seem to know your stuff on this forum and glad it is so active.

I purchased a 2000 528i (Dark green, sport package, 180k) from my father who kept it in pretty good condition.

Mine has the ABS, brake (amber) and traction control lights on. It recently has started having intermittent spedometer failure (sometime will work when car is started and other times won't work at all) and cruise control failure. I will follow this procedure and try to figure out which sensors are out. I have a mechanic buddy who works in a ford shop and has some of his own stuff (non-bmw specific) at his house for dx. Also have another former e36 M3 owner who did a lot of his own work so I feel b/w the three of us we can tackle these issues.

Any other thoughts on the speedo/cruise control issues or is this probably the underlying issue?

Also which brand do you guys suggest? Is it ok to go non-OEM for half the price or better to pony up for OEM BMW parts?

Black Magic
09-05-2017, 07:52 PM
I can relay my experience. I purchased PEX brand rear wheel speed sensors and the only improvement was that the speedometer started working again. I still had transmission shifting issues and various ABS lights on. I brought my E39 to a BMW dealer who evaluated it and found that the rear wheel speed sensors were not reporting. I solved the problem by returning the PEX sensors and replaced them with Siemens. Issue resolved. Siemens cost $80 more per sensor than the PEX. The time frame on that was 3/13 and who knows, PEX could have solved their problems by now.

Rumzdizzle
09-06-2017, 10:09 AM
I can relay my experience. I purchased PEX brand rear wheel speed sensors and the only improvement was that the speedometer started working again. I still had transmission shifting issues and various ABS lights on. I brought my E39 to a BMW dealer who evaluated it and found that the rear wheel speed sensors were not reporting. I solved the problem by returning the PEX sensors and replaced them with Siemens. Issue resolved. Siemens cost $80 more per sensor than the PEX. The time frame on that was 3/13 and who knows, PEX could have solved their problems by now.

Thank you fellow Kansan! Will prob go with the Siemens, nice middle ground sensor as far as cost is concerned.