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Thread: Why are my Traction Control (ASC/DSC), ABS and Brake lights illuminated?

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    98 540iA (Prd 11/97)

    Why are my Traction Control (ASC/DSC), ABS and Brake lights illuminated?

    Quote Originally Posted by bluebee View Post
    You didn't mention if you had all three yellow lights, ABS/BRAKE/DSC, so, maybe your problem is different, but, by replacing the wheel speed sensor without (presumably) first testing it, you're just throwing money at the problem.
    Here is my standard cut-and-paste response for the ABS/BRAKE/DSC yellow trifecta ...
    (All this information is from teaming up with Bill (540iman[/URL]) and gathering additional details from BlackBMWs, BMW_n00b13, TheStig, Edgy36-39, Max_VQ, PharoE39, freewilly[/URL], BAMF[/URL], and others).
    Three solid yellow ABS/Brake/DSC lights almost always indicates a classic BMW problem:
    1. Go to the first thread in the E39 forums (the VERY best of E39 Links[/URL])
    2. Search for ABS (you'll find this post[/URL])
    3. Click on this canonical summary[/URL] in that post (in addition, see http://www.bimmerfest.com/forums/showpost.php?p=5300549&postcount=1"]Bill's 'logic' of testing ABS sensors[/URL]).
    Note: The lights may come on all at once, or one at a time, and they may be intermittent, and in the beginning they may go out when you restart the car but come back; eventually they become lit solid all the time. It's all the same problem when you have the ABS Brake DSC trifecta!
    Luckily, almost always, resolution is quick, simple, and reasonably inexpensive:
    - Quick: In a half hour with a DMM, you'll know exactly what components failed;
    - Simple: Removal of speed sensors (<$100 each) and/or the ABS control module (<$500 new) is a ten-minute job each;
    - Cheap: My ABS control module rebuild cost me $150 USD, in toto, including tax & shipping (most people report successful rebuilds under $300).
    In summary, the flow-chart procedure to follow (summarized from this thread[/URL]) is:
    a. Open the hood, disconnect the ABS control module harness & check the four wheel speed sensors with a DMM;
    b. If any wheel speed sensor tests bad, doublecheck at the appropriate wheel; replace the bad one with an OE sensor[/URL] (<$100, rarely more than one!);
    c. If all four speed sensors are good, simply send your ABS control module to BBA/MM/ATE (recommended in that order) for a rebuild ($300-$150 in toto);
    d. If the rebuilder can't repair your module (takes about 5 days overall), buy a new module ($480 from Jared at EACTuning) & have the VIN recoded at the stealer (about $120).
    In almost all (if not all) ABS, Brake, & DSC light trifecta situations, it's that simple!
    BTW, while your ABS control module is out of the car (about 5 days), the following anomalies[/URL] may occur:
    - Brake/DSC/ABS trifecta solid yellow lights (on the instrument cluster)
    - Service Engine Soon (SES) solid yellow light lit (on the instrument cluster)
    - No ABS[/URL] (upon hard braking under low-traction conditions)
    - No traction control (DSC or ASC on lateral action)
    - No speedometer (use a portable GPS navigation unit if you're worried about that)
    - No odometer (again, use a portable GPS unit if this bothers you)
    - No tripmeter (use a portable GPS unit if it's a worry to you)
    - No cruise control
    - OBDII diagnostic trouble code DTC P0500, i.e., bad speed sensor (clear by driving or with an OBDII scanner)
    - No possibility of passing (California at least) smog inspections (until you replace the ABS control module & clear the DTC)
    - No speed-sensitive automatic door locks (if enabled at the stealer)
    - No GPS (if you have navigation)
    - No mileage calculations on the instrument cluster
    - No fuel consumption calculations on the instrument cluster
    - No range indications on the instrument cluster
    - No speed-sensitive radio (if equipped)
    - No speed-sensitive wipers (if equipped)
    - Erratic fuel gauge (especially when near empty, so keep the tank at greater than 3/4 at all times)
    - Erratic transmission shifting (if automatic; if it bothers you, switch to manual shifting)
    SUMMARY:
    The problem is usually a single wheel sensor goes bad (wires or the <$100 sensor), or the ABS control module goes bad (a steel resistance-welded wire lifts off its bond pad, Bill kindly ran a full autopsy here[/URL]). Debugging is best done with a DMM; an OBDII scanner can ONLY find "communication errors", i.e., it cannot tell a bad speed or pressure sensor from a bad ABS control module and will often report the wrong problem because it isn't inserted BETWEEN the ABS control module and the various sensors (see extensive reports by 540iman on this[/URL]). The ABS control module costs ~$150 to $300 to rebuild, ~$500 to replace; if you put anything back on other than your original ABS control module, the VIN will need to be recoded[/URL] (15 minutes with a GT-1 or Autologic or similar; impossible otherwise). You'll need to clear your OBDII DTC codes after you fix everything if you plan on passing smog tests that week (ask me how I know[/URL]). If you need to replace a speed sensor, don't go aftermarket; get as close to OE [/URL]as possible.
    Before you send your ABS control module out for rebuilding, please consider opening it up first, post pictures to Bill's ABS autopsy thread[/URL] (the rebuilders say they work on previously opened ABS control modules all the time). If you fix the broken wire, post that to the thread as a success story!
    Quote Originally Posted by bluebee View Post
    Here is my attempt at combining information for our ABS DIY repair writeup in a single post:
    Credit: Extensive leverage from other sources; as new information comes in, I will update this post as long as it will let me.
    Future: Maybe someone can put a copy of this in the DIY section after it's properly reviewed for mistakes.

    CLASSIC ABS FAILURE SYMPTOMS:
    - Most of the time, the problem is the ABS module or one of the 4 wheel speed sensors (& sometimes the brake pressure sensor)
    - In my 2002 BMW E39 DSC, three orange (warning) cluster display lights lit, ABS, Brake, & DSC
    - The 3 warning lights reset when the ignition is turned off, only to repeatedly reappear within minutes of normal driving
    - The fault is often intermittent leading you to falsely believe you've resolved the problem (proper diagnosis is important)
    - Sometimes the fault only appears when the engine is hot; other times only at speeds over 40 mph
    - Carsoft may erroneously show a rear speed sensor failure; but just replacing the speed sensor may make no difference.
    - All the work is in correct diagnosis of the problem[/URL]; parts replacement is trivial (from 1 to six bolts in a few minutes)
    - Hence, this BMW E39 ABS 3-warning light DIY will concentrate on understanding and diagnosis of the problem


    FALSE ALARM SANITY CHECK:
    If you recently drove on ice, a dynamometer, or on another very slippery surface, the car may just think the system has malfunctioned.
    - Driving a few miles on a regular surface should fix the problem.
    - Another fix is to slowly turn the steering wheel from completely left to completely right, then back again.
    - The warning lights will reset whenever you turn the car off (but go back on if the fault persists)
    BMW DESIGN PROBLEM:
    - The E39 ABS module was mounted too close to engine heat causing solder cracks & fried electronics
    - The 4 wheel sensors and wires are exposed to the elements and to shocks/vibration
    - The 3 steering yaw sensors seem pretty well protected from both hazards but they may need recalibration[/URL]
    Note: Apparently newer-model BMWs moved the ABS module further away from engine heat (need confirmation)
    FLOW CHART OF RECOMMENDED ACTIONS:
    0) Watch, for a few days, speedo, odometer, tripmeter, cruise control, transmission, & ABS/BRAKE/DSC light activity
    1) If ABS/BRAKE/DSC constantly comes back, test the 4 wheel sensor circuits from the ABS module connector
    2) If any sensor circuit shows up as bad, test that specific sensor itself at that wheel (otherwise skip to step 5)
    3) If the wheel sensor still shows up as bad, first remove, clean, grease, and re-install that sensor
    4) If it still tests bad, then replace the sensor
    ...
    5) If the sensors are good, test the ABS circuit with the Carsoft or Peake tools (or just assume a bad ABS module)
    6) If the Carsoft or Peake tools indicate a different sensor, test & replace that sensor (e.g., pressure, yaw, acceleration, etc.)
    7) Otherwise, assume your ABS module is the culprit (some say get your ABS module rebuilt anyway as it's going to go eventually)
    ...
    8) If your ABS module is suspected, you have only the following 5 options:
    - OPTION 0: You can do nothing and just not have ABS or DSC (not a good choice for anyone on this message board)
    - OPTION 1: You can attempt a 3-part rebuild yourself (unfortunately we don't have enough information to help you yet)
    - OPTION 2: You can send your module out for a rebuild (about 1/3 to 1/2 can be rebuilt but you'll have no speedo in the interim)
    - OPTION 3: You can buy a rebuilt module (you'll have to add approximately $100 for a VIN recode at the dealer)
    - OPTION 4: You can buy a brand new module (you'll again have to pay for a BMW dealership recoding to your VIN)
    Note: Most people don't deal with testing the other 15 items; they just opt for sending their ABS module out to be rebuilt, which isn't necessarily a bad thing because generally it is the ABS and even if it isn't, some argue it's not a bad idea to rebuild even a working ABS.
    READ THE SHOP MANUAL: ( http://www.bentleypublishers.com/isb...179/index.html )
    - For DSC pinouts, see Volume II, page ELE-15 of ABS/DSC controle module (A65) (2 sensors in the front and 2 in the rear)
    - For ASC pinouts, see Volume II, page ELE-21 of ABS/ASC controle module (A52) (only 1 sensor in the front and 1 in the rear)
    - For ABS/ASC/DSC system operation, see Volume I, page 300-12 (it's not all that useful though)
    - For ABS/ASC/DSC system components, see Volume I, page 340-26 (again, not all that useful if you have this)
    READ BMW MANUALS:
    - Bosch DSC part 1[/URL], Bosch DSC part II[/URL] (kindly supplied[/URL] by Max_VQ[/URL])
    READ THESE ARTICLES:
    - http://www.meeknet.co.uk/E38/ABS/Index.htm
    - http://forums.bimmerforums.com/forum...d.php?t=600452
    - http://forums.bimmerforums.com/forum....php?t=1230488
    - http://cparente.wordpress.com/2008/1...o-abs-problem/
    - http://www.bimmerfest.com/forums/sho...d.php?t=363554
    - http://www.bimmerfest.com/forums/sho...39#post4202239
    etc.
    UNDERSTAND DIGITAL MULTIMETER (DMM) TEST BASICS:
    - http://www.allaboutcircuits.com/vol_3/chpt_3/2.html

    GATHER SEAT-OF-THE-PANTS DATA:
    - Note exactly which warning indicators are lit (e.g., ABS & BRAKE & DSC)
    - Note whether cruise control is working or not (sometimes implicates the passenger-side rear sensor)
    - Note whether the speedometer (hence odometer & tripmeter) is working (sometimes implicates the driver-side rear sensor)
    - Note "free play", "dead spots", & "centering" of the steering wheel (sometimes implicates steering column sensors)
    - Note if normal ABS pulsation (ABS working) or skidding (ABS not working) when hard braking on sandy shoulders at 15 mph
    - Note if violent shudder[/URL] (ABS working) or screech (ABS not working) when firm braking on top of speed bumps at 5mph
    Note: It's not always just the sensor when the speedometer is also out with the 3 lights (the key is diagnosis)
    ACKNOWLEDGE ALL POSSIBLE (20) & MOST LIKELY (2) CULPRITS:
    • 1 BOSCH DC III Control Module 83 Pin (combined with the hydraulic unit in my E39, DSC III Bosch 5.7) <==COMMON CULPRIT!
    • 1 Hydraulic Unit (combined with the control module in my E39, DSC III Bosch 5.7)
    • Hydraulic Unit contains: 2 pre-charge solenoid valves
    • Hydraulic Unit contains: 2 changeover solenoid valves
    • Hydraulic Unit contains: 4 intake solenoid valves
    • Hydraulic Unit contains: 4 outlet solenoid valves
    • Hydraulic Unit contains: 1 return pump
    • 2 Front Wheel Speed Sensors (Active Hall Effect) in the steering knuckles, secured with two 4 mm allen bolts <==COMMON CULPRIT!
    • 2 Rear Wheel Speed Sensors (Active Hall Effect) in the rear wheel bearing carriers, secured with one 4 mm allen bolt <==COMMON CULPRIT!
    • 1 Hydraulic Pressure Sensor (attached to the front-brake hydraulic unit in my E39, DSC III Bosch 5.7) <==MY PROBLEM!
    • 1 Steering Angle Sensor (located in the bottom of the steering column, near the flexible coupling)
    • 1 Rotation Rate, aka Yaw Sensor (combined with the lateral-acceleration sensor in my E39, DSC III Bosch 5.7)
    • 1 Lateral Acceleration Sensor (combined with the yaw sensor in my E39, DSC III Bosch 5.7)
    • 1 DSC Switch (located below the radio in the cockpit)
    • 1 Hand Brake Switch (located on the hand brake assembly)
    • 1 Brake Switch (located on the brake-pedal assembly)
    • 1 Pre-Charging Pump
    • 1 Charging Piston (750iL only)
    PHOTOGRAPH OF THE MOST LIKELY CULPRITS:

    GATHER DESIRED TOOLS:
    - Print this DIY out, bring a pencil to mark down your readings, and a drink
    - Digital multi meter (DMM) with a diode-test capability & long, very narrow probes
    - About six inches of 20 AWG stiff wire (to attach to your DMM probes and to the female ABS connector)
    - A small piece of white or yellow tape so that you can label the positive stiff wire (to avoid confusion with the negative probe)
    - T20 six-point Torx bit in a 1/4" socket with a 6" extension for removing the ABS control module
    - 4mm allen wrench for removing the front wheel sensors
    - Torque wrench (see torque tables below) for replacing components
    - For rear sensors, a 10 mm socket, 8 mm socket, flat-head screwdriver, and needle-nose pliers might be required to remove trim.
    - 1/4-inch wide 6-inch long standard flathead screwdriver for removing ABS harness connector clip
    - CRC cleaner (or equivalent brake cleaner)
    - Staburags NBU 12/K or equivalent grease (for speed sensors and connections in the housings)

    GATHER OPTIONAL TOOLS:
    - (maybe) 10mm socket for removing air filter box (easier access for some E39 models)
    - Carsoft 6.5 or Peake Research or equivalent OBDII diagnostic scanner
    - Oscilloscope (look for millivolt square waves coming from powered sensors as the wheel turns)
    - Note: Carsoft 6.5 can't perform encoding, activation, or steering adjustments.
    - Note: Bad ABS modules often report erroneous indications of a bad RR sensor in the OBD scanner reports
    - Note: You must use new bolts for the ABS Control Module (according to the Bentleys)

    PRICE OEM PARTS:
    - Repair kit, control unit DSC, $1,120 + $112 (~10% tax) = $1,232 (often colloquially referred to as the "ABS control unit")
    - Wheel sensors, front, $134 x 2 = $268 + $27 (~10% tax) = $295 total (some suggested EAC tuning for wheel sensors)
    - Wheel sensors rear, $201 x 2 = = $402 + $40 (~10% tax) = $442 total (some suggested AutoHauz for wheel sensors)
    - Front brake pressure sensor, $111 + 10% tax = ~$125 (measures 0-250bars of front-brake pressure, outputs 0-5 volts)
    - Steering angle (yaw) sensors (in the steering wheel column or under driver's seat) ~$250 each (almost never needed)
    - Hydro unit, DSC, $2,003 x 1 + $200 (~10% tax) = $2,013 (this "hydro unit" behind the ABS control unit is almost never at fault)
    Note: If you replace the ABS module, you'll also need a $100 dealership recoding to your VIN & steering angles calibrated (apparently)
    PRICE REBUILDING OF YOUR ABS MODULE:
    - Module Masters ($105) http://www.modulemaster.com/en/abs/ate_bmw_asc.php
    - BBA Remanufacturing (8 days, $225) http://www.bba-reman.com
    - Auto & Truck Electronics ($105) EBAY seller's ID ATE1234, lifetime warranty, free shipping, quick turnaround
    - Note: A rebuild of your ABS unit won't require VIN coding, activation, or steering angle calibration
    PRICE A REBUILT ABS MODULE FROM ANOTHER VEHICLE:
    - For a rebuilt part, most suggest oembimmerparts.com[/URL], one of our sponsors[/URL], at about $450 + $45 tax = $500
    - Note: A rebuilt ABS unit from another vehicle requires a $100 dealership VIN recoding effort
    QUESTION: What happens if you don't code the VIN & check steering angles ... (does the car blow up?)
    CONSIDER FIXING IT YOURSELF (we need much more details to make this option viable):
    - Open up the module & look for broken solder joints which can be sucked and resoldered (take pictures)
    - Add point-to-point wiring where needed (we need more information to make this actionable)
    - Replace diodes and any other weak parts with more robust parts (again, not very useful unless we know exactly what)
    - Post before and after pictures so each of us can learn from the rest
    CHECK BMW ERROR CODES:
    - Locate the OBDII port, by law, in the cockpit, within 3 feet of the driver (above the driver's left knee in American BMWs)
    - Hook up Carsoft[/URL] or Peake diagnostic tools[/URL] to the OBDII port to determine any error codes
    - Cross reference Carsoft error codes[/URL] with the list of Bosch 5.7 error codes listed bellow (kindly supplied by Max_VQ[/URL])
    Note: Some say this check is of dubious value because a bad ABS module may show up as a bad rear sensor[/URL]; always test the sensor itself!
    BMW ABS/ASC Bosch[/URL] 5.7 Table of error codes:[/URL]
    5 Right Rear Wheel Speed Sensor
    6 Right Front Wheel Speed Sensor
    7 Front Left Wheel Speed Sensor
    14 Solenoid Valve Relay (check fuses 17 & 33)
    15 Pressure Sensor/Pump Error
    21 Module Memory Failure - ABS/ASC module is faulty
    23 Incorrect Coding - ABS/ASC module is faulty
    24 Wrong Impulse
    30 Left Rear Wheel Speed Sensor
    31 Open Right Rear Wheel Speed Sensor
    32 Open Right Front Wheel Speed Sensor
    33 Open Left Front Wheel Speed Sensor
    50 Right Front Outlet Valve - ABS/ASC module is faulty
    51 Left Rear Outlet Valve - ABS/ASC module is faulty
    54 Left Front Inlet Valve - ABS/ASC module is faulty
    55 ASC Intake Valve - ABS/ASC module is faulty
    58 Gear Box Control Unit (CAN bus error)
    59 DMER1 (CAN bus error)
    61 Steering Angle Sensor Identification
    66 Speed Sensor Voltage Supply
    67 Intermittent Interference
    75 Engine Speed Fault from DME
    81 Pressure Sensor
    82 Open Yaw Rate Sensor
    86 ASC Cut-off Valve Rear Axle
    88 Precharge Pump
    89 Low Voltage
    90 Temporary System Deactivation
    94 DDE Fault/Yaw rate sensor
    97 Steering Angle Sensor
    10 Brake Light Switch
    108 SN Control
    112 Open CAN to Instrument Cluster
    114 Pressure Sensor Offset
    117 Brake Light Switch Failure
    118 DME Status-Internal Error
    REMOVE ABS-MODULE CONNECTOR:
    - Facing the engine, slide the plastic retaining clip to the right with a 1/4 inch flathead screwdriver.
    - It is a plastic retaining clip, so do be careful not to break it; it slides over about 1 1/4 inches or so.
    - Once the clip is fully to the right, lift the electrical connector up
    - Notice the female (blue) connector with 42 holes (and very tiny lettering)
    - DO NOT STICK YOUR TEST LEAD INTO THE SQUARE HOLES!
    (Only put test leads into the larger rectangular holes next to the square holes.)

    NOTE ABS-MODULE PINOUT: (notice the test lead holes)
    - Each wheel sensor circuit has a set of two wires in the ABS connector (pinout[/URL] kindly supplied by 540iman[/URL])
    - ABS-connector pins 13,29 = Left rear wheel sensor (also affects speedometer & odometer & tripmeter)
    - ABS-connector pins 30,31 = Right rear wheel sensor (also affects cruise control)
    - ABS-connector pins 28,12 = Left front wheel sensor (some say it also acts as a steering angle sensor[/URL])
    - ABS-connector pins 15,16 = Right front wheel sensor (tells gearbox electronics how fast you're going[/URL])
    Note: These pinouts are in the same order of the diode action of each sensor (do not reverse these numbers)
    Note: Don't confuse with the brake pad wear sensor, which is only located on the front left & rear right wheel & which uses a black connector.
    Note: ASC cars have only two sensors, one on the front right and the other on the rear left wheel.
    UNDERSTAND WHEEL SPEED SENSORS:
    Note: The wheel speed sensors are two-wire hall effect transducers which send a digital square wave signal with a low of .75 volts and a high of 2.5 volts to the DSC control unit. Each sensor receives a well-regulated 8 volt power supply from the control module through one wire. The ground path for the sensor is through the second wire back to the control module. The signal is generated by a pulse wheel affecting the voltage flow through the hall element in the sensor. The pulse wheel is integrated into the wheel bearing assembly, behind the seal. This protects the trigger wheel from foreign substances which may affect the wheel speed signal.

    TEST WHEEL SENSOR CIRCUIT FROM THE ABS CONNECTOR (also checks wiring circuit):
    OPTIONAL: Jack car up (so that all four wheels can be spun to test voltage & resistance fluctuations of the hall-effect sensors)
    - Turn the car off and remove the key from the ignition.
    - TEST 1: Switch the DMM into the diode test position
    - Wrap a stiff 20AWG wire onto the ends of your DMM probe for sticking into ABS-connector pins
    - Label the positive 20AWG wire with white tape so that you won't get confused as you switch back and forth
    - Stick the ends of the wire into the appropriate female holes of the ABS connector (13-29, 30-31, 28-12, 15-16)
    - In one direction, you should see 1.7 to 1.8 volts (note the pinouts mentioned are in order, positive to negative)
    - In the other direction, you should see OL or some other infinite reading (open circuit)
    - TEST 2: Switch the DMM into resistance checking mode (optional)
    - You should see around 3.3 Mega ohms in one direction & approximately twice that in the other direction (but some say more[/URL])
    - TEST 3: If desired spin the wheel at about 1 revolution per second[/URL], by hand (the resistance should fluctuate as the wheel spins[/URL])
    - TEST 4: Switch the DMM into millivolt mode (optional) & again spin the tire & wheel assembly by hand (test-lead polarity won't matter)
    - You should read between 1 and 5 mV when you spin the hub[/URL] (no voltage implicate the sensor or circuit)
    - OPTIONAL TESTS BELOW REQUIRE FLYING LEADS WITH THE IGNITION SYSTEM ABS SYSTEM CONNECTED & POWERED UP:
    - TEST 5: Swith the DMM into the 10v and attach flying leads to the sensors with the power on
    - You should see the voltage going to the sensor and the return signal[/URL]
    - Expect a baseline voltage of about +5 to +12 volts depending on the ABS system (does anyone know this value?)
    - Expect that baseline voltage to the sensor to change (by how much?) as you spin the wheels
    - TEST 6: Hook an oscilloscope with "flying leads" to the ABS sensors (notice that the ABS system must be powered)
    - You should see nice clean square waves generated as you hand spin the wheels[/URL] at about 1 revolution per second.
    Note: The oscilliscope can detect problems [/URL]that can't easily be found with a DMM (A scope pattern for a wheel speed sensor should show a classic sine wave alternating current pattern that changes both in frequency and amplitude with wheel speed. As the wheel is turned faster, signal frequency and amplitude should both increase. Damaged or missing teeth on the sensor ring will show up as flat spots or gaps in the sine wave pattern. A bent axle or hub will produce an undulating pattern that changes as the strength of the sensor signal changes with every revolution. If the scope pattern produced by the sensor is flattened (diminished amplitude) or is erratic, it usually indicates a weak signal caused by an excessively wide air gap between the tip of the sensor and its ring, or a buildup of metallic debris on the end of the sensor. A weak signal can also be caused by internal resistance in the sensor or its wiring circuit, or loose or corroded wiring connectors.)

    INTERPRET DIODE-TEST RESULTS:
    - If the DMM, in diode mode, reads infinity ("OL") in both directions, you've got a bad sensor or circuit
    - If the DMM, in resistance mode, reads much greater than 7Mohms, you've got a bad sensor or circuit
    - If all 4 sensors read OK, it's most likely the ABS control unit.
    - If you think you found two bad sensors, you probably messed up.
    - Rarely is the cause due to bad steering angle (yaw/lew) sensors
    - Rarely is the cause due to a bad hydro unit
    - The problem is almost always a wheel rotation sensor or the ABS control unit
    ACTUAL RESULTS ON MY 2002 E39 THIS MEMORIAL DAY WEEKEND:

    DOUBLECHECK WHEEL SENSORS AT THE WHEEL:
    Note: You can run this test w/o removing the wheel but access to the sensor connector is easier with the wheels off the E39
    - If one or more sensor circuits test bad in any of the three tests above ... then ...
    - Locate the sensor blue connector in the rear of each front wheel well by turning the front wheels
    - Easiest to first locate the sensor (bolted on the wheel carrier near the hub) and trace its wire back to a black plastic hinged box housing
    - Open the locked hinged plastic rectangular black box with a small flathead screwdriver
    - Locate the blue wheel sensor connector (next to a black brake wear sensor connector)
    - Pull the blue wheel sensor connector out of the box and disconnect the two sides
    - Re-check the sensor there with the diode function of the DMM

    CHECK WHEEL SENSORS OFF THE VEHICLE:
    - If any sensor still checks bad, pull the sensor off the vehicle for a closer inspection
    - Chock wheels and jack E39 BMW and jack stand at the 4 jack pad locations
    - Remove 4mm allen head bolts to sensor retention screw (two retaining bolts for fronts, 1 bolt for the rears)
    - Pull wheel sensor out of hub assembly, straight up.
    - Clean with CRC electronic cleaner
    - Check with DMM diode-test meter as before
    - Grease with Staburags NBU 12/K or equivalent grease
    - Replace sensor back into hub assembly, snug tighten to 6 foot pounds
    - Replace rear wheel, tighten to 82 to 96 foot pounds
    Note: You might wish to swap sensors on the same axle when replacing so as to obtain further diagnostic information should an anomaly occur.
    Note: Here is a picture of a dirty and cleaned sensor (magnetic particle buildup[/URL])

    TEST BRAKE PRESSURE SENSOR (aka HYDRAULIC UNIT PRESSURE SENSOR):
    - This test procedure kindly suggested by Max_VQ:
    - Given 250 bar = 3,626 psi, and given 0-5 volts linear proportional output, 3,626 psi/ 5v = 725.2 psi/volt or 1.3 mV per psi.
    - With the ignition on, measure the voltage on the pressure sensor while someone is pressing hard on the brake pedal
    - My guess is that should create about 3,000 psi of force and should show around 4.13 volts.
    - At rest it should show very close to 0 volts
    Note: The front-brake pressure sensor provides a 0-5 volt linear voltage signal to the DSC III control module which is proportionate to how hard the driver is pressing on the brake pedal, from zero to 250 bars (3,626 psi), spanning (a) no braking, to (b) partial braking, and to (c) near-ABS-regulation state braking. This brake pressure sensor has three pins (a) power, (b) ground and (c) the 0-5 volt proportionate signal.
    Note: By way of comparison, the Corvette also has a brake pressure sensor to indicate how hard the brakes are being applied; it monitors pressure from 0 to 2000psi generating a corresponding signal of 0.20 volts to 4.80 volts[/URL].
    LOCATION OF FRONT-BRAKE PRESSURE SENSOR:
    • DSC III 5.3 (740i/iL and 540i) - The brake pressure sensor is located in the charge pump assembly.
    • DSC III 5.3 (750iL) - The sensor is located on the charge piston unit.
    • DSC III 5.7 (ALL) - The sensor is located on the hydraulic unit on my 2002 E39.

    TEST ROTATION RATE & LATERAL ACCELERATION SENSOR:
    - We do not yet have a test for this sensor; a description of operation is all we have at the moment (please suggest a test procedure so all benefit)
    - On Bosch DSC III (Bosch 5.7) the Rotation Rate sensor (yaw) and the Lateral Acceleration sensor have been combined into one unit located under the drivers seat under the carpet
    - The degree of rotation rate (yaw) transducer outputs a reference signal of 2.5 volts and a linear voltage of 0.7 to 4.3 volts
    - The lateral acceleration output signal should be 1.7 volts while the car is sitting still on a flat surface corresponding to 0 G side forces.
    - The lateral acceleration transducer outputs a linear voltage of 0.5 to 4.5 volts corresponding to a G-Force range of -1.5 to +3.5 G side forces depending on the motion of a fixed capacitor plate relative to a floating capacitor plate.

    TEST STEERING ANGLE SENSOR:
    - We don't yet know how to test the steering-angle sensor (please advise)
    Note: The steering angle sensor, mounted at the bottom of the steering column near the flexible coupling, utilizes two potentiometers to determine the steering angle and the rate of steering angle change, which are are the two raw signals the CAN bus microprocessor utilizes to create the steering angle signal for broadcast over the CAN bus. The DSC III logic compares the stored plausibility of the steering angle sensor against other DSC III inputs (front wheel speeds, rotation rate and lateral acceleration sensors).
    STEERING ANGLE SENSOR:


    REMOVE ABS MODULE:
    - Remove the six T20 Torx screws holding the ABS module to the hydro unit
    - Pull the ABS module straight out towards the passenger side headlight.
    - Cover the hydro unit with aluminum foil to protect it from the elements
    - You can drive the car but you won't have a speedometer or odometer
    - Use a portable GPS unit with a speed display as your temporary speedometer
    - You may not have cruise control (need to test this)
    - Of course, you won't have ABS either but you didn't have that anyway

    HINTS TO HELP OTHERS:
    - Consider taking apart your ABS module and posting before rebuild and after rebuild pictures
    - Consider paying rebuilders the extra $10 to return ABS modules that failed[/URL] (so you can take it apart & post pictures)
    - Consider selling your old module to the rebuilders if you buy a new or rebuilt ABS module from another vehicle
    - A portable GPS unit doubles as a speedometer in the interim while your ABS module is being rebuilt
    REINSTALL ABS MODULE:
    - Note: There is a gasket attached to the new unit.
    - Carefully place the new module over the control actuators.
    - Loosely replace the six new T20 Torx screws included with the new module.
    - Tighten snug tight, and then a little more to seat the gasket.
    - Reposition the ABS electrical connector
    - Press down on the ABS connector while pushing the retaining clip to the left
    - Reassemble the Air Filter box & MAF (if it was disassembled for Torx access).

    INITIALIZE ABS MODULES:
    - Note: This step is only necessary if you installed an ABS module that wasn't originally in the car in the first place
    - Take the E39 to an Indy to encode the VIN (I'm not sure what happens if you don't do this)
    - Take the E39 to an Indy to check and adjust the steering angle (I'm not sure why)
    - Some say the steering angle sensor may have to be recalibrated when you put on a remanufactured or new ABS module.
    TORQUE TABLE:
    - 4mm wheel sensor bolts (two each for the front sensors, 1 each for the rear sensors) = 6 foot pounds
    - Combination lateral acceleration/rotational rate sensor (under driver seat) = 6 foot pounds
    - DSC bolts to the hydraulic unit (new bolts only) = 26 inch pounds
    - Hydraulic unit to body = 6 foot pounds
    - Hydraulic unit mounting bracket = 6 foot pounds
    - Brake lines to hydraulic unit = 13 foot pounds
    - Wheel lug nuts = 82 to 96 foot pounds
    DIAGRAM OF THE 2002 E39 DSC III BOSCH 5.7 SYSTEM:

    USE THIS CHART TO DETERMINE WHICH ABS SYSTEM YOU HAVE:

    Note: This ABS repair thread was compiled from scores of sources; special credit goes to many people, especially 540iman[/URL], BlackBMWs[/URL], Max_VQ[/URL], Edgy36-39[/URL], and others.
    Quote Originally Posted by bimmerfiver View Post
    I wasn't able to take photographs. However I want to share the success of a new ABS Module from Jared of EAC Tuning http://eactuning.com/.

    My 2003 525 had the misfortune of encountering a bad ABS Module. Symptoms? The dummy lights come on your instrument cluster, the triangle with the arrow around it, the brake light and ABS light...they all came on (in yellow color) and stayed that way.

    My speedometer and cruise control worked fine, so it wasn't one of the rear sensors. The hope was that one of the front wheel sensors was at fault. I bought a new sensor for the front, tried it in either side and nope, that didn't work. My local indy's scanner read that it was a charge pump for the ABS system...

    At the dealership, the scanner told us that it was the ABS Module. My tech there offered, "Ninety-nine percent of the time, it's the ABS Module." New, the ABS Module can cost around $1000.00 so I spoke with Jared and his price is fantastic (see http://eactuning.com/).

    Jared shipped it on time and today was D-Day. I prayed to all 6' hot German supermodels and to the Gods of the Autobahn too. My dealership installed the new module (it's easy but does require one's attention) and coded it...for those that don't know, your car's computer needs to have an instant message sent to it, letting it know, "Here's a new ABS Module." Our modules have codes, a combination of numbers that have to be unlocked via software.

    It took one hour total. The tech came back from a test drive and said it was fine. I did jumping jacks in the parking lot and then I drove it. Sure enough it works 100%! I pulled out of the parking lot, floored it on the sand/ice and the traction control kicked in. I then pulled over, put her in park, hit my DSC button and turned the traction control off. I did this several times and all is well.

    Look men, Tiger Woods is coming back in April, Lance Armstrong is back already, Britney is on the treadmill, working out, dancing while wearing underwear this time and President Obama is almost on the job, why not get your E39's ABS system on the comeback trail?

    EAC Tuning's price is # 1 for the ABS Module, it's new, not refurbed and I should be fine for quite a while.

    http://eactuning.com/

    http://www.youtube.com/watch?v=R34dXi_44Qg
    .
    Last edited by jamesdc4; 07-15-2013 at 02:01 PM.

  2. #2
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    This should be stickied or added to the FAQ. Great info as always, thanks!

    Going into my TENTH YEAR of providing high quality reproduction BMW fabrics!

    PRICE CUT on ALL FABRICS
    Offering the best prices on the best quality reproduction fabrics!

  3. #3
    Join Date
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    Quote Originally Posted by blackxs View Post
    This should be stickied or added to the FAQ. Great info as always, thanks!
    No problem. It's already in the FAQ. This is just an update to include a comprehensive thread on the subject.
    Last edited by jamesdc4; 01-22-2010 at 11:23 PM.

  4. #4
    Join Date
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    2000 BMW 528i Sedan

    Unhappy ABS trifecta - and ... brake pad lights(?)

    my cruise control stopped working, my abs, dsc, and brake lights are on, but my brake pads light is on too. I have a 2000 (528i) E39. I replace the speed sensor, but it looks like the brake wear sensor is bad too - does this make sense? my trifecta and pads lights didn't go off after i replace the right rear speed sensor this morning. And I have had my back brakes and one rotor replaced (the one with the burnt out brake wear sensor) (right rear) But now my cruise control works. IS it too soon for the engine to have reset? we unplugged the battery while we replaced the sensor wheel/speed sensor. My speedometer is and always has been just fine. Could it be a different sensor? I think I had all of them tested previously (those lights were on for a while and were diagnosed by someone who seemed less than sure) THANKS!!! ALSO - my hand brake isn't too stable. I have to park the car and then put it in gear to keep the car from moving. My question - Do I need an abs rebuild to make those lights go off, or am i overlooking something. my cruise control works fine now...

  5. #5
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    That's a lot going on, the cruise control issue sounds like it may be an ignition switch. search the forum for symptoms.

  6. #6
    Join Date
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    District Heights, MD
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    2000 BMW 528i Sedan

    Red face

    THANKS! that was what i have been looking for, and everyone has symptoms similar but not quite the same as mine. THEN, it always differs by something that looks small, but is quite significant. Is it possible that I have several things wrong? Maybe I should fix the ignition switch first and THEN the ABS lights will go out? It's just that I need to pass an emissions test and so I have to fix the trifecta lights issue because it is causing me to fail.

    QUESTION - Does anyone know if i remove my ABS module if the lights will go out? OH WAIT - they (the MVA) would know I didn't have a speedometer or something right? SIGH... I just need more time and money ...
    Last edited by tsalleypfc; 11-25-2011 at 03:42 PM.

  7. #7
    Join Date
    Jan 2007
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    West Michigan
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    98 540iA (Prd 11/97)
    Quote Originally Posted by Bcbp14 View Post
    That's a lot going on, the cruise control issue sounds like it may be an ignition switch. search the forum for symptoms.
    He can try the visor test to try to confirm a bad/failing Ignition Switch.
    What are the symptoms of a failing Ignition Switch?
    Quote Originally Posted by tsalleypfc View Post
    But now my cruise control works. my cruise control works fine now...
    Quote Originally Posted by tsalleypfc View Post
    QUESTION - Does anyone know if i remove my ABS module if the lights will go out? OH WAIT - they (the MVA) would know I didn't have a speedometer or something right? SIGH... I just need more time and money ...
    Just removing your ABS module will not get rid of the trifecta. As a matter of fact, Blubee lists all the things that might happen if you remove the module and run without it...

    BTW, while your ABS control module is out of the car (about 5 days), the following anomalies may occur:
    - Brake/DSC/ABS trifecta solid yellow lights (on the instrument cluster)
    - Service Engine Soon (SES) solid yellow light lit (on the instrument cluster)
    - No ABS[/URL] (upon hard braking under low-traction conditions)
    - No traction control (DSC or ASC on lateral action)
    - No speedometer (use a portable GPS navigation unit if you're worried about that)
    - No odometer (again, use a portable GPS unit if this bothers you)
    - No tripmeter (use a portable GPS unit if it's a worry to you)
    - No cruise control
    - OBDII diagnostic trouble code DTC P0500, i.e., bad speed sensor (clear by driving or with an OBDII scanner)
    - No possibility of passing (California at least) smog inspections (until you replace the ABS control module & clear the DTC)
    - No speed-sensitive automatic door locks (if enabled at the stealer)
    - No GPS (if you have navigation)
    - No mileage calculations on the instrument cluster
    - No fuel consumption calculations on the instrument cluster
    - No range indications on the instrument cluster
    - No speed-sensitive radio (if equipped)
    - No speed-sensitive wipers (if equipped)
    - Erratic fuel gauge (especially when near empty, so keep the tank at greater than 3/4 at all times)
    - Erratic transmission shifting (if automatic; if it bothers you, switch to manual shifting)

    Also, I don't believe the Ignition Switch has anything to do with your ABS/DSC/Brake problem. The CC problem may have been unrelated.
    Unless I'm missing something, the usual suspects are (in this order)...

    Luckily, almost always, resolution is quick, simple, and reasonably inexpensive:
    - Quick:
    In a half hour with a DMM, you'll know exactly what components failed;
    - Simple: Removal of speed sensors (<$100 each) and/or the ABS control module (<$500 new) is a ten-minute job each;
    - Cheap: My ABS control module rebuild cost me $150 USD, in toto, including tax & shipping (most people report successful rebuilds under $300).
    In summary, the flow-chart procedure to follow (summarized from this thread[/URL]) is:
    a. Open the hood, disconnect the ABS control module harness & check the four wheel speed sensors with a DMM;
    b. If any wheel speed sensor tests bad, doublecheck at the appropriate wheel; replace the bad one with an
    OE sensor[/URL] (<$100, rarely more than one!);
    c. If all four speed sensors are good, simply send your ABS control module to BBA/MM/ATE (recommended in that order) for a rebuild ($300-$150 in toto);
    d. If the rebuilder can't repair your module (takes about 5 days overall), buy a new module ($480 from Jared at EACTuning) & have the VIN recoded at the stealer (about $120).
    In almost all (if not all) ABS, Brake, & DSC light trifecta situations, it's that simple!
    Last edited by jamesdc4; 11-25-2011 at 05:10 PM.

  8. #8
    Join Date
    Nov 2011
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    LOL!!!! simple, thanks! *gulp* I will print this out and start hacking away at it immediately!

  9. #9
    Join Date
    Sep 2011
    Location
    Orlando, fl
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    4
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    2006 550i
    Hello, I have a 1999 540i and had the same three lights. Took it for service and the mechanic said no error codes stored. Maybe something between the computer and cluster. He wants to charge $100/hour to perform troubleshooting. Has anyone ever had this problem?

  10. #10
    Join Date
    Oct 2008
    Location
    N.W. Indiana
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    '02 540i
    My opinion for those who know me and my efforts to resolve this issue many times is that you have two totally seperate issues going on unrelated, but maybe coincidence on timing. Brake pad sensor- check your pads. If they are good and you are willing to keep an eye on them is just disconnect pad sensors-LF then RF until light goes away. Tuck them up outta the way and keep an eye on your pad wear the "old fashioned way".

    Trifecta you can diagnose yourself. Sometimes people read some of BlueBee's posts and they are so lengthy (but I support them 100%) they may scare some away. I can give you the down and dirty way to test sensors and go from there. Get a decent (not Menards $9.99 job) but spend a few bucks on a Fluke 86 or similar meter as you will have for life. Needs a diode check feature. All good meters will have this. Not essential, but helps.rather than give $100 to your mechanic-you CAN do this. When you have the meter, look up your pin numbers for each sensor. Disconnect large connector from ABS module itself breaking the connecting between ABS and all else. They with a paperclip cleaned of all clear sealer (very important) you are going to check each speed sensor one at a time. Take a paper clip and soak it is gas or scrap both ends with a pocket knife. Most all clear paper clips have a clear coating on them which will not let electricity pass. make sure you connect meter across two paper clips and that they conduct perfectly. Come back to me or PM me whan you are ready to move on. neither code is dangerous-just your traction and stability control won't function like the good old days.
    Save you money, and diagnose yourself. You are not getting a really critical error.
    Bill
    Old, contrary, and out-of-touch,
    but still learning sumpin' every day
    NOTORIOUSLY long-winded :-(

  11. #11
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    Bothell, WA USA
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    2000 BMW M5
    I have been having the same issue for a couple months now, and it started in the middle of a long road trip. My DSC, ABS, and Brake lights come on. The Speedo shows 0 MPH, and the Odo stops too. The Cruise Control works fine. This is INTERMITTENT, but comes on just about every single day.

    I've read through the posts here, and just have a single question: does the intermittent nature of my indicate it is more likely a ABS control module, or a speed sensor?

    Thanks,
    John Kirkland

  12. #12
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    Apr 2009
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    2001/2002 530i 1999 528i
    Quote Originally Posted by jkirkland75 View Post
    I have been having the same issue for a couple months now, and it started in the middle of a long road trip. My DSC, ABS, and Brake lights come on. The Speedo shows 0 MPH, and the Odo stops too. The Cruise Control works fine. This is INTERMITTENT, but comes on just about every single day.

    I've read through the posts here, and just have a single question: does the intermittent nature of my indicate it is more likely a ABS control module, or a speed sensor?

    Thanks,
    John Kirkland
    My 99 ABS Module solder joints failed this same way at higher temps and got progressively worse -auto tranny went into limp mode

  13. #13
    Join Date
    Sep 2012
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    Owasso, OK.
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    2000 BMW 540i/6 M-Sport
    I thought I might have had this problem, but it doesn't seem that I do anymore. The BRAKE light is on and red, not yellow, and the ABS light is not on except for the few seconds once you key-on, and the traction control light stays on. Car is a 2000 540i 6spd. Any help would be appreciated

    And there's no codes, but my displays says "check brake xxxxx" idk what the last word is. Might say linings, might say lines, I can't tell, haha its irritating.
    Last edited by moss500berg; 09-15-2012 at 07:37 PM.

  14. #14
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    Apr 2009
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    New Hyde Park NY
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    2001/2002 530i 1999 528i
    Quote Originally Posted by moss500berg View Post
    I thought I might have had this problem, but it doesn't seem that I do anymore. The BRAKE light is on and red, not yellow, and the ABS light is not on except for the few seconds once you key-on, and the traction control light stays on. Car is a 2000 540i 6spd. Any help would be appreciated

    And there's no codes, but my displays says "check brake xxxxx" idk what the last word is. Might say linings, might say lines, I can't tell, haha its irritating.
    Is your handbrake fully down and handbrake switch functioning properly?
    How about Blade fluid level? If they all check out, then I suspect that you are seeing 2 of the three (Tri-fecta) classic ABS Module symptoms.

    I read elsewhere that 1999 and 2000 MY ABS modules are more prone to failure and my vehicle experiences support that - my 2001 with over 146K miles has not had this issue but the 1999 did at just over 100K

  15. #15
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    2000 BMW 540i/6 M-Sport
    Quote Originally Posted by mahmoudh View Post
    Is your handbrake fully down and handbrake switch functioning properly?
    How about Blade fluid level? If they all check out, then I suspect that you are seeing 2 of the three (Tri-fecta) classic ABS Module symptoms.

    I read elsewhere that 1999 and 2000 MY ABS modules are more prone to failure and my vehicle experiences support that - my 2001 with over 146K miles has not had this issue but the 1999 did at just over 100K
    Yes the handbrake is all the way down, and I'm sure the switch is functioning properly. I did have a message that came up that told me to check the brake fluid, and it was indeed low,

    I'm starting to think it says linings, and that would explain the brake light, but not the traction control.

  16. #16
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    This is a Great write up,, I did the speed wheel sensor test today. Everything checked out ok,, I think its the ABS module, But just for grins im going to replace my front tires because they are so badly cupped that it could be throwing a front wheel sensor,,Yea that bad,,


  17. #17
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    This is a Great write up,, I did the speed wheel sensor test today. Everything checked out ok,, I think its the ABS module, But just for grins im going to replace my front tires because they are so badly cupped that it could be throwing a front wheel sensor,,Yea that bad,,


  18. #18
    Join Date
    Aug 2012
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    97 E39 540/6
    Is it normal for the lights to go off intermittently? Yesterday morning when I start the car the DCS/ABS lights were on. I left the drive way and the lights went off for about 10 minutes before coming back on for the rest of the day. Today- the lights were on when I started the car but stayed off for the rest of the day- ? I'm really hoping its just a sensor or something. Did anyone elses do this?

    "Life is a numbers game. Increase the numbers, win the game"

  19. #19
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    Quote Originally Posted by Only1Balto View Post
    - Is it normal for the lights to go off intermittently?
    - Did anyone elses do this?
    Yes and yes. But only if the system is starting to fail. I know that's probably not what you wanted to read, but I believe that's what you're looking at. Start troubleshooting by checking your wheel speed sensors first. Hopefully that will be your problem. Is your CEL illuminated?



    5284me,

    Why did you delete your post? The problems above aren't DSC specific. They apply to ASC as well. If you're having the problem you posted, you can probably get help with it here on the boards.
    Last edited by jamesdc4; 02-02-2013 at 04:53 PM.

  20. #20
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    My same lights intermittently went on and off (and my speedo stopped working). When I replaced the Drivers Rear wheel sensor, it took care of it and has never returned.

  21. #21
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    Quote Originally Posted by 5284me View Post
    My same lights intermittently went on and off (and my speedo stopped working). When I replaced the Drivers Rear wheel sensor, it took care of it and has never returned.
    Thanks for the response. Another reason I asked is because posting your issue and solution adds to the collective. It's not unusual to get members posting problems but never posting back when and if the issue is resolved. Thanks again for your contribution and congrats on the fix.

  22. #22
    Join Date
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    5284me,

    Why did you delete your post? The problems above aren't DSC specific. They apply to ASC as well. If you're having the problem you posted, you can probably get help with it here on the boards.
    Hey there,

    As I re-read my post, it "kind of duplicated" what symptoms others have had / and that were posted in the thread. (and... I noticed that I could have been a little more clear in the way I described it). After reading it a few times, I thought it looked a little confusing and it didn't really add too much to the thread so I was going to delete it and clarify then re-post but never did. I thought it would kind of look redundant.

    I 100% agree with you. It's soooooo nice when someone posts back as to what the fix was, as opposed to just letting the thread die. That's why I wanted continue to follow the thread and to post (that in my case), the Drivers side rear sensor did take care of the intermittent problem as described above.
    Last edited by 5284me; 02-02-2013 at 11:06 PM.

  23. #23
    Join Date
    Jun 2013
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    California
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    2001 BMW 740i M Sport
    Hi all,

    This information has been very useful. I used the information you all provided and took it an extra step.

    I FOUND THE CAUSE OF THE PROBLEM
    that turns the Trifecta Amber lights combination ABS, Brake, and Traction Control warning lights. Although I failed in my attempt to fix it so hopefully someone else has a good solution.

    Root Cause of the problem:
    Inside of the ABS module, there are several soldered wire joints (silver) that appear to become brittle over time and break. These connections are very small (smaller than your average soldered connections in the back of an instrument cluster) and with very limited space it is tough to work on these. IMPORTANT: Next to these small silver connections, there are A LOT OF tiny-thin ANGEL HAIR type GOLDEN CONNECTIONS THAT ARE VERY DIFFICULT TO SEE EVEN WITH A MAGNIFYING GLASS, you can see them by playing with the angle of vision so that light reflects back on them. How small? Approximately 1/10 the thickness of a blonde's hair.

    The break in the wire, as I was able to notice them, can only be seen with a magnifying glass (I have 20/20 vision) and was not able to see the break without the magnifying glass. In order to confirm the break I used tweezers and small scrapers to test the connection and I found 3 broken silver wires (these wire are very flexible and become brittle on the connecting part, it is possible I may have broken one of these connections while testing them; however one of these was already broken for sure). I may have also smashed together or broken 1 or 2 golden wires but they are so small I cannot even test for that.

    This video shows the failure that occurs; it was the same failure in mine. The ABS module in the video I believe is one model older than mine (Mine is the Bosch 5.7) but the problem is the same, video link:

    These were my steps:

    My control module is the following:
    ABS Control Module - BMW 5.7
    PN: 0265 950 002
    Vehicle: 2001 BMW 740i

    My steps were as follows:


    • I first confirmed the problem to be the ABS Module and not either of the other possible combinations that could cause the light problems. Note that fixing, repairing, rebuilding or remanufacturing the ABS module will not fix the trifecta lights if the root cause of the problem is not the module.

    1- Remove ABS control unit from vehicle - 0265 950 002
    2- Remove sealed plastic cap (cap next to plug connection and sitting 90degrees as compared to plug)
    3 - Very carefully, using a magnifying glass and with very small pick tools, identify the broken connections (3 broken connections identified)
    THE FOLLOWING STEPS WERE DONE ONLY TO THE BAD CONNECTIONS
    4- Remove protective silicon layer over the bad connections
    5- Prepare for soldering
    5a - Clean connections with Print Kote Solvent
    5b - Remove pre-applied solder
    6- ---- At this point, when I attepmted to solder the bad connections I was not able to do it. After about an hour of not being able to do it, I went to ebay and found your Repair SErvice.
    7 - I re-sealed the cap and re-installed on the 2001 BMW 740i
    8 - Vehicle drives as before, same lights on (amber Traction Control, ABS, Brake).
    9 – New created issue with new broken connections or possibly breaking or joining the angel hair gold connections.

    • Intermittent problem: Speedometer not working, which in turn causes the following problems when the speedometer is not working and set at ZERO:
      • Fuel gauge needle fluctuation, (just like driving let’s say Honda civic or Toyota camry), it works but you can see it fluctuate due to curves, angles, etc
      • Proximity sensors: both the front and rear proximity sensors remain ACTIVATED and ON while driving the car, therefore when driving lets say at 55mph and a car gets within range from my car the sensors start beeping.
      • FUEL RANGE: the fuel range seems to be a bit on the crazy side ranging up and down constantly. Drives you nuts when the fuel level is below Ό of a tank.



    I’m skilled to a certain level with PCBs but I couldn’t fix this one. Who can fix my ABS unit?
    Please see attached pictures. The debris seen in the pictures is from cutting the sealed cap open.

    Best Regards,

    iKarz

    ikarz.com
    Instrument Cluster Repairs

  24. #24
    Join Date
    Feb 2011
    Location
    Manchester, CT
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    2000 BMW 540iA
    I think the problem you will have at this point is that none of the ABS unit re-builders will not touch a unit that has been previously opened by the owner. I expect that at this point you will need to probably buy a new unit and have it coded to the car. New ABS/DSC control units are usually in the $450-600 range online.

  25. #25
    Join Date
    Jul 2007
    Location
    Los Angeles, CA
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    01 525i
    Also as a heads up, if anyone is in socal needing a module rebuilt I found a place in Van Nuys that will do it while you wait (took about 2 hours to fix mine) and it was $150 with a lifetime warranty.

    http://www.shop.modulerepairpro.com/
    Apparently my sig was too sexy for bf.c
    Click for teh sexiness...

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