Esp/Abs problem
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Esp/Abs problem
The post will be long because I've been struggling with the problem for quite a long time. I have simply run out of ideas. I kindly ask for advice, maybe one of you will be able to guide me.
Mercedes w251 R class 2011 3.0 cdi 265 HP
The car is going to the workshop for:
- regeneration of the transfer case - a new chain and two sprockets with seals are installed
- replacement of two front shock absorbers (pneumatic)
- replacement of the rack - the old one is leaking - a new Lizarte replacement is installed
- replacement of two rigid rear brake lines
The effect?
After picking up the car from the workshop, when turning right, the car turns on the ESP and brakes the wheels. When driving straight ahead everything is ok.
What was checked replaced
- 4 new hubs
- 4 new ABS sensors
- overload sensor b25/15
Rig test done after everything
No errors on SD, wheel speeds perfectly equal, brake lines not swapped, system bled, machine under pressure, hard brake. Steering angle sensor at zero. Geometry has been set.
I am slowly losing hope. Maybe one of you will be able to lead me to the cause of such car behavior.
I will be grateful for any hint,
Marcin
Mercedes w251 R class 2011 3.0 cdi 265 HP
The car is going to the workshop for:
- regeneration of the transfer case - a new chain and two sprockets with seals are installed
- replacement of two front shock absorbers (pneumatic)
- replacement of the rack - the old one is leaking - a new Lizarte replacement is installed
- replacement of two rigid rear brake lines
The effect?
After picking up the car from the workshop, when turning right, the car turns on the ESP and brakes the wheels. When driving straight ahead everything is ok.
What was checked replaced
- 4 new hubs
- 4 new ABS sensors
- overload sensor b25/15
Rig test done after everything
No errors on SD, wheel speeds perfectly equal, brake lines not swapped, system bled, machine under pressure, hard brake. Steering angle sensor at zero. Geometry has been set.
I am slowly losing hope. Maybe one of you will be able to lead me to the cause of such car behavior.
I will be grateful for any hint,
Marcin
Out Of Control!!
Joined: Apr 2019
Posts: 11,823
Likes: 6,707
From: Silicon Valley
W212 MY'14 M276-3.5NA @75kMi
Troublesome ESP....
The post will be long because I've been struggling with the problem for quite a long time. I have simply run out of ideas. I kindly ask for advice, maybe one of you will be able to guide me.
Mercedes w251 R class 2011 3.0 cdi 265 HP
The car is going to the workshop for:
- regeneration of the transfer case - a new chain and two sprockets with seals are installed
- replacement of two front shock absorbers (pneumatic)
- replacement of the rack - the old one is leaking - a new Lizarte replacement is installed
- replacement of two rigid rear brake lines
The effect?
After picking up the car from the workshop, when turning right, the car turns on the ESP and brakes the wheels. When driving straight ahead everything is ok.
What was checked replaced
- 4 new hubs
- 4 new ABS sensors
- overload sensor b25/15
Rig test done after everything
No errors on SD, wheel speeds perfectly equal, brake lines not swapped, system bled, machine under pressure, hard brake. Steering angle sensor at zero. Geometry has been set.
I am slowly losing hope. Maybe one of you will be able to lead me to the cause of such car behavior.
I will be grateful for any hint,
Marcin
Mercedes w251 R class 2011 3.0 cdi 265 HP
The car is going to the workshop for:
- regeneration of the transfer case - a new chain and two sprockets with seals are installed
- replacement of two front shock absorbers (pneumatic)
- replacement of the rack - the old one is leaking - a new Lizarte replacement is installed
- replacement of two rigid rear brake lines
The effect?
After picking up the car from the workshop, when turning right, the car turns on the ESP and brakes the wheels. When driving straight ahead everything is ok.
What was checked replaced
- 4 new hubs
- 4 new ABS sensors
- overload sensor b25/15
Rig test done after everything
No errors on SD, wheel speeds perfectly equal, brake lines not swapped, system bled, machine under pressure, hard brake. Steering angle sensor at zero. Geometry has been set.
I am slowly losing hope. Maybe one of you will be able to lead me to the cause of such car behavior.
I will be grateful for any hint,
Marcin
We understand you do have new hubs and new wheel sensors and a good steering angle.
With everything that was done and replaced: it should work yet something is quietly spoiling your ownership.
> Something to note is that Bosch ESP module can substitute bad values on the fly. So I recommend you spin each wheel one at the time and watch corresponding live ESP DATA PID.
> In addition the steering angle module is interfaced through the solderless SCM Module that is not particularly reliable. Make sure you scan the whole chassis and that CAN-Bus modules are not disrupted with fault collection.
> Scrutinize your ESP live data for weird/missing values... meaning don't blindly trust ESP to flag what is wrong. Dig in line by line.
> Do you trust replacement sensors/hub are exact MB part match or aftermarket compatibles??
🤞
> Lastly you can begin to suspect ESP module itself may have grown connection oxidation if it is acting up randomly... Your case is always while turning only, right?
Last edited by CaliBenzDriver; Jan 26, 2025 at 06:23 AM.
Newbie
Joined: Feb 2026
Posts: 5
Likes: 0
R350 CDI 4Matic 2011 (W251)
The post will be long because I've been struggling with the problem for quite a long time. I have simply run out of ideas. I kindly ask for advice, maybe one of you will be able to guide me.
Mercedes w251 R class 2011 3.0 cdi 265 HP
The car is going to the workshop for:
- regeneration of the transfer case - a new chain and two sprockets with seals are installed
- replacement of two front shock absorbers (pneumatic)
- replacement of the rack - the old one is leaking - a new Lizarte replacement is installed
- replacement of two rigid rear brake lines
The effect?
After picking up the car from the workshop, when turning right, the car turns on the ESP and brakes the wheels. When driving straight ahead everything is ok.
What was checked replaced
- 4 new hubs
- 4 new ABS sensors
- overload sensor b25/15
Rig test done after everything
No errors on SD, wheel speeds perfectly equal, brake lines not swapped, system bled, machine under pressure, hard brake. Steering angle sensor at zero. Geometry has been set.
I am slowly losing hope. Maybe one of you will be able to lead me to the cause of such car behavior.
I will be grateful for any hint,
Marcin
Mercedes w251 R class 2011 3.0 cdi 265 HP
The car is going to the workshop for:
- regeneration of the transfer case - a new chain and two sprockets with seals are installed
- replacement of two front shock absorbers (pneumatic)
- replacement of the rack - the old one is leaking - a new Lizarte replacement is installed
- replacement of two rigid rear brake lines
The effect?
After picking up the car from the workshop, when turning right, the car turns on the ESP and brakes the wheels. When driving straight ahead everything is ok.
What was checked replaced
- 4 new hubs
- 4 new ABS sensors
- overload sensor b25/15
Rig test done after everything
No errors on SD, wheel speeds perfectly equal, brake lines not swapped, system bled, machine under pressure, hard brake. Steering angle sensor at zero. Geometry has been set.
I am slowly losing hope. Maybe one of you will be able to lead me to the cause of such car behavior.
I will be grateful for any hint,
Marcin
I've found your post as we too are experiencing something very similar.
ABS pump activating on right turns, occasionally on left but not to the same degree, and mainly only when the car is 'on load', i.e. there is a little throttle (passively turning without throttle and at very low speed seems to be benign). Our mechanic is a bit stumped (and he's extremely good & methodical).
Bearings are good. RPM sensors are good (including on live tests). Steering module good and recalibrated. Yaw sensor was flickering between zero and -0.2 when stationery which was odd, so we replaced and recalibrated with a younger used part just to be sure (weirdly no difference in the flickering... could it be wiring or CAN-Bus reading/broadcasting??).
One weird thing to note is that as of 1 month ago and roughly corresponding to this ABS issue, the 'Run Flat Indicator' available via the dash trip menu has completely disappeared, as in no longer even an available option. This being a 2011 UK W251 I believe the run flat is a passive system that uses the RPM/ABS sensor data rather than individual rim-valve based pressure sensors that actually provide pressure readings (Canada & USA only?).
Our mechanic has suggested sending the ABS pump for benchmarking exercise, which could reveal if there are any circuit glitches affecting that aren't throwing a formal fault code, as per CaliBenzDriver's sensible suggestion. We're assuming that the ABS pump module is the same as the Bosch ESP module he is referring to (i.e. they are an integrated ABS/ESP unit sharing circuitry)?
Any feedback would be greatly appreciated, as we'll happily post an update as and when we investigate further.
Cheers, Mark.
Newbie
Joined: Feb 2026
Posts: 5
Likes: 0
R350 CDI 4Matic 2011 (W251)
Hey CaliBenzDriver, wondering if you've encountered anything similar to the post you replied to here since the OP first listed?
We've had a similar issue and along with our mechanic are seemingly banging our heads on a the proverbial
Cheers, Mark
We've had a similar issue and along with our mechanic are seemingly banging our heads on a the proverbial
Cheers, Mark
Newbie
Joined: Feb 2026
Posts: 5
Likes: 0
R350 CDI 4Matic 2011 (W251)
The post will be long because I've been struggling with the problem for quite a long time. I have simply run out of ideas. I kindly ask for advice, maybe one of you will be able to guide me.
Mercedes w251 R class 2011 3.0 cdi 265 HP
The car is going to the workshop for:
- regeneration of the transfer case - a new chain and two sprockets with seals are installed
- replacement of two front shock absorbers (pneumatic)
- replacement of the rack - the old one is leaking - a new Lizarte replacement is installed
- replacement of two rigid rear brake lines
The effect?
After picking up the car from the workshop, when turning right, the car turns on the ESP and brakes the wheels. When driving straight ahead everything is ok.
What was checked replaced
- 4 new hubs
- 4 new ABS sensors
- overload sensor b25/15
Rig test done after everything
No errors on SD, wheel speeds perfectly equal, brake lines not swapped, system bled, machine under pressure, hard brake. Steering angle sensor at zero. Geometry has been set.
I am slowly losing hope. Maybe one of you will be able to lead me to the cause of such car behavior.
I will be grateful for any hint,
Marcin
Mercedes w251 R class 2011 3.0 cdi 265 HP
The car is going to the workshop for:
- regeneration of the transfer case - a new chain and two sprockets with seals are installed
- replacement of two front shock absorbers (pneumatic)
- replacement of the rack - the old one is leaking - a new Lizarte replacement is installed
- replacement of two rigid rear brake lines
The effect?
After picking up the car from the workshop, when turning right, the car turns on the ESP and brakes the wheels. When driving straight ahead everything is ok.
What was checked replaced
- 4 new hubs
- 4 new ABS sensors
- overload sensor b25/15
Rig test done after everything
No errors on SD, wheel speeds perfectly equal, brake lines not swapped, system bled, machine under pressure, hard brake. Steering angle sensor at zero. Geometry has been set.
I am slowly losing hope. Maybe one of you will be able to lead me to the cause of such car behavior.
I will be grateful for any hint,
Marcin
I've found your post as we too are experiencing something very similar.
ABS pump activating on right turns, occasionally on left but not to the same degree, and mainly only when the car is 'on load', i.e. there is a little throttle (passively turning without throttle and at very low speed seems to be benign). Our mechanic is a bit stumped (and he's extremely good & methodical).
Bearings are good. RPM sensors are good (including on live tests). Steering module good and recalibrated. Yaw sensor was flickering between zero and -0.2 when stationery which was odd, so we replaced and recalibrated with a younger used part just to be sure (weirdly no difference in the flickering... could it be wiring or CAN-Bus reading/broadcasting??).
One weird thing to note is that as of 1 month ago and roughly corresponding to this ABS issue, the 'Run Flat Indicator' available via the dash trip menu has completely disappeared, as in no longer even an available option. This being a 2011 UK W251 I believe the run flat is a passive system that uses the RPM/ABS sensor data rather than individual rim-valve based pressure sensors that actually provide pressure readings (Canada & USA only?).
Our mechanic has suggested sending the ABS pump for benchmarking exercise, which could reveal if there are any circuit glitches affecting that aren't throwing a formal fault code, as per CaliBenzDriver's sensible suggestion. We're assuming that the ABS pump module is the same as the Bosch ESP module he is referring to (i.e. they are an integrated ABS/ESP unit sharing circuitry)?
Any feedback would be greatly appreciated, as we'll happily post an update as and when we investigate further.
Cheers, Mark.
