W140 ABS/ETS lights; any ideas?
Discussion
Hello folks,
Hoping to get some advice on a problem with my 1996 W140 S280.
The car lights up the ETS and ABS warning lights on an intermittent basis, usually when the car is starting from cold. If I start the car from warm the problem often disappears.
I've had recurring issues with the ABS system over the past 6 months, in which time the following have been replaced:
- ABS Reluctor Rings on the rear axle.
- Front Passenger Side Brake Caliper (wheel speed sensor cleaned and transferred).
- Brake Light Switch (as of today).
The first two issues cured the problem for around 4 months from when they were fixed in July , and the fresh symptoms suggested to me that it was the classic brake light switch problem.
I have the MOT this week (UK statutory test for roadworthiness) and it goes without saying that this problem needs to be sorted out for that.
Sometimes I have heavy steering and cruise control failure while the lights are on, however again these problems appear to be intermittent.
I thought that the Brake Light Switch change would finally solve these problems, but it doesn't seem to have made a difference. I have also tried pulling the fuses and resetting the battery for half an hour.
The car goes in to the garage tomorrow for its annual service and MOT, so I wonder if anyone has any idea of what else might be amiss? My initial thoughts are to look at the Front Driver wheelspeed sensor and rear axle wheelspeed sensor... I wonder if anyone has any other ideas on what could be wrong with it?
Kind Regards,
AJMC
Hoping to get some advice on a problem with my 1996 W140 S280.
The car lights up the ETS and ABS warning lights on an intermittent basis, usually when the car is starting from cold. If I start the car from warm the problem often disappears.
I've had recurring issues with the ABS system over the past 6 months, in which time the following have been replaced:
- ABS Reluctor Rings on the rear axle.
- Front Passenger Side Brake Caliper (wheel speed sensor cleaned and transferred).
- Brake Light Switch (as of today).
The first two issues cured the problem for around 4 months from when they were fixed in July , and the fresh symptoms suggested to me that it was the classic brake light switch problem.
I have the MOT this week (UK statutory test for roadworthiness) and it goes without saying that this problem needs to be sorted out for that.
Sometimes I have heavy steering and cruise control failure while the lights are on, however again these problems appear to be intermittent.
I thought that the Brake Light Switch change would finally solve these problems, but it doesn't seem to have made a difference. I have also tried pulling the fuses and resetting the battery for half an hour.
The car goes in to the garage tomorrow for its annual service and MOT, so I wonder if anyone has any idea of what else might be amiss? My initial thoughts are to look at the Front Driver wheelspeed sensor and rear axle wheelspeed sensor... I wonder if anyone has any other ideas on what could be wrong with it?
Kind Regards,
AJMC
Hi Ray,
Many thanks for your input, will certainly be reading the codes if possible, may involve a trip to MB to get the full STAR codes. What happened to your car sounds all too familiar, I hope you don't mind me asking but do you remember if it was an expensive fix at all? I know that this era of Merc was known for harness issues...
Kind Regards,
Alex
Many thanks for your input, will certainly be reading the codes if possible, may involve a trip to MB to get the full STAR codes. What happened to your car sounds all too familiar, I hope you don't mind me asking but do you remember if it was an expensive fix at all? I know that this era of Merc was known for harness issues...
Kind Regards,
Alex
Use an indy for the codes, my local one will only charge £30. Before I read the codes I was stumbling around in the dark so took me ages to sort.
It was a cheap fix, a length of 4 core cable, and some heat shrink.
The old cable must have allowed some water ingress, the copper core had turned to dust!
It was a cheap fix, a length of 4 core cable, and some heat shrink.
The old cable must have allowed some water ingress, the copper core had turned to dust!
tobinen said:
Is your battery in good condition? I ask because I have the BAS/ESP light on (ok not the same warning) and I am pretty certain with all the short journeys I do with lots of electrics on, it's lowered the voltage enough to throw on the warning light.
Hey there, haven't had any problems with the battery so far (seems to hold charge etc)... garage are leaving it with a trickle charge on over the weekend so we'll see how we get on with that!I read somewhere that too much voltage can be a problem too, as it can trigger one of the relay/fuses in the 'coffin' box on the passenger side of the engine compartment, so will have that checked out too!
A month in, and after a lot of banging my head against a brick wall trying to work out what's going on, we have an answer of sorts...
Got a full STAR Diags test done, the code pulled was C1102-000 ETS Rpm sensor RL L6/3 Wiring.
On closer inspection of the sensor, it looks like it's the unit itself that has given up the ghost.
Only trouble is, tracking down a rear left sensor proving to be a ghastly job.
There are lots of adverts online for rear right units, but none at all (in this country at least) to be had for the left. Carl at R129co was very helpful, and originally had a part for me which unfortunately broke as he was trying to remove it, so the hunt continues! To make things more confusing, there are about 3 different sensor configurations depending on the model year and specification of any given W140, so it's taken me hours to find out exactly what part is required.
The part I need is 1405402017 (Mercedes Part No) or 0265006181 (Bosch), I wonder if anyone knows where one might be found?
Really hope I can get to the bottom of this soon, as it's my only car up here and it's been in for well over a month now!
One starts to wonder what would have happened if I'd just removed the ABS bulb before going near a test centre...
Best,
A.
Got a full STAR Diags test done, the code pulled was C1102-000 ETS Rpm sensor RL L6/3 Wiring.
On closer inspection of the sensor, it looks like it's the unit itself that has given up the ghost.
Only trouble is, tracking down a rear left sensor proving to be a ghastly job.
There are lots of adverts online for rear right units, but none at all (in this country at least) to be had for the left. Carl at R129co was very helpful, and originally had a part for me which unfortunately broke as he was trying to remove it, so the hunt continues! To make things more confusing, there are about 3 different sensor configurations depending on the model year and specification of any given W140, so it's taken me hours to find out exactly what part is required.
The part I need is 1405402017 (Mercedes Part No) or 0265006181 (Bosch), I wonder if anyone knows where one might be found?
Really hope I can get to the bottom of this soon, as it's my only car up here and it's been in for well over a month now!
One starts to wonder what would have happened if I'd just removed the ABS bulb before going near a test centre...
Best,
A.
ajmcampbell said:
A month in, and after a lot of banging my head against a brick wall trying to work out what's going on, we have an answer of sorts...
Got a full STAR Diags test done, the code pulled was C1102-000 ETS Rpm sensor RL L6/3 Wiring.
On closer inspection of the sensor, it looks like it's the unit itself that has given up the ghost.
Only trouble is, tracking down a rear left sensor proving to be a ghastly job.
There are lots of adverts online for rear right units, but none at all (in this country at least) to be had for the left. Carl at R129co was very helpful, and originally had a part for me which unfortunately broke as he was trying to remove it, so the hunt continues! To make things more confusing, there are about 3 different sensor configurations depending on the model year and specification of any given W140, so it's taken me hours to find out exactly what part is required.
The part I need is 1405402017 (Mercedes Part No) or 0265006181 (Bosch), I wonder if anyone knows where one might be found?
Really hope I can get to the bottom of this soon, as it's my only car up here and it's been in for well over a month now!
One starts to wonder what would have happened if I'd just removed the ABS bulb before going near a test centre...
Best,
A.
Try a dealer. Got a full STAR Diags test done, the code pulled was C1102-000 ETS Rpm sensor RL L6/3 Wiring.
On closer inspection of the sensor, it looks like it's the unit itself that has given up the ghost.
Only trouble is, tracking down a rear left sensor proving to be a ghastly job.
There are lots of adverts online for rear right units, but none at all (in this country at least) to be had for the left. Carl at R129co was very helpful, and originally had a part for me which unfortunately broke as he was trying to remove it, so the hunt continues! To make things more confusing, there are about 3 different sensor configurations depending on the model year and specification of any given W140, so it's taken me hours to find out exactly what part is required.
The part I need is 1405402017 (Mercedes Part No) or 0265006181 (Bosch), I wonder if anyone knows where one might be found?
Really hope I can get to the bottom of this soon, as it's my only car up here and it's been in for well over a month now!
One starts to wonder what would have happened if I'd just removed the ABS bulb before going near a test centre...
Best,
A.
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