ABS/ESP/Service Brake Fault problem, Help, please!
03-27-2021, 05:08 PM
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2006 E320 CDI
ABS/ESP/Service Brake Fault problem, Help, please!
Very strange happenings I today, need some help. Has anyone seen this? Here's the pertinent info.
2006 W211 E320 CDI
Last night and today I did some work on the car .
1. Replaced right front wheel bearing
2. Replaced left and right front brake pads. To do this I disconnected the SBC nodule under the hood. During the process I started the car to turn the wheel left and right for access. During which the dash was all red with warnings about a brake system failure. Normal and expected, no big deal, I never touched the brake pedal.
3. During all of this I took off the winters snow tires rims and put on the summer. Same sizes, nothing unusual there.
4. Changed the fuel filter.
So everything is back together and reconnected the SBC module. She starts right up. I notice a check engine light, hit it with the scanner to find P0720 (I think that's what it was) for a fault related to powertrain sensor. Strange because the car hadn't moved or even taken out of park. I cleared out the code and carried on.
I go to drive and check the brakes, everything starts out fine, then three warnings show up on the dash:
ABS faultESP fault
Brake fault - Service brake
I think by service brake they mean parking brake, but not sure.
I'm stumped. Maybe stressed the wheel speed sensor front right when I changed the bearing, but only if I hit it with a tool or something, it never got disconnected. Everything looks ok under there.
Any ideas?
Thanks,
Pete
2006 W211 E320 CDI
Last night and today I did some work on the car .
1. Replaced right front wheel bearing
2. Replaced left and right front brake pads. To do this I disconnected the SBC nodule under the hood. During the process I started the car to turn the wheel left and right for access. During which the dash was all red with warnings about a brake system failure. Normal and expected, no big deal, I never touched the brake pedal.
3. During all of this I took off the winters snow tires rims and put on the summer. Same sizes, nothing unusual there.
4. Changed the fuel filter.
So everything is back together and reconnected the SBC module. She starts right up. I notice a check engine light, hit it with the scanner to find P0720 (I think that's what it was) for a fault related to powertrain sensor. Strange because the car hadn't moved or even taken out of park. I cleared out the code and carried on.
I go to drive and check the brakes, everything starts out fine, then three warnings show up on the dash:
ABS faultESP fault
Brake fault - Service brake
I think by service brake they mean parking brake, but not sure.
I'm stumped. Maybe stressed the wheel speed sensor front right when I changed the bearing, but only if I hit it with a tool or something, it never got disconnected. Everything looks ok under there.
Any ideas?
Thanks,
Pete
03-27-2021, 05:32 PM
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'71 Pinto
See if following attached instructions inclusive of activation process clears fault messages if not, you may need MB diagnostics.
03-28-2021, 03:16 PM
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2006 E320 CDI
Solved!
Ok, did a lot of research last night and learned how the wheel speed sensors on these cars work.
In this case, the magnetic ring that the wheel speed sensor reads is contained within the rubber portion of the bearing seal. Somehow I had a large glob of grease on top of the wheel speed sensor and that was enough it seems to block the signal.
All back together and all the codes are gone.
I've only had this car 2 months, but I've owed one in the past, glad to have it back. Just learned though doing the brakes that someone working on it in the past liked to loctite all the bolts. Ugh. Broke off the one that holds the brake wear sensor and had to drill and tap a larger bolt in there.
In this case, the magnetic ring that the wheel speed sensor reads is contained within the rubber portion of the bearing seal. Somehow I had a large glob of grease on top of the wheel speed sensor and that was enough it seems to block the signal.
All back together and all the codes are gone.
I've only had this car 2 months, but I've owed one in the past, glad to have it back. Just learned though doing the brakes that someone working on it in the past liked to loctite all the bolts. Ugh. Broke off the one that holds the brake wear sensor and had to drill and tap a larger bolt in there.
