PeachParts Mercedes-Benz Forum - ASR Light

PeachParts Mercedes-Benz Forum (http://www.peachparts.com/shopforum/)

- Tech Help (http://www.peachparts.com/shopforum/tech-help/)

- - ASR Light - HELP M.B. DOC ! (http://www.peachparts.com/shopforum/tech-help/139853-asr-light-help-m-b-doc.html)

ASR problem - pot or cable?

Jim:
You refer to a "pot" - is this a variable resistor connected to the accellerator pedal or is it inside the ETA? I am starting to suspect a mechanical linkage/accellerator pedal assembly problem at this point, rather than the ETA's, which both seem to be functioning normally, and the cable harnesses are practically new (actually, judging by the stickers on both ETA's, it appears now they were both replaced a few years ago).
Maybe I got lucky. I will keep you posted.
I have spent many hours on the net researching posts related to ASR problems, and there are some trends emerging which will allow me to compile all the various symptoms related to ASR problems, and facilitate diagnosing the various causes.
For example, if the ASR light comes on (as in my case) while the car is idling, at a standstill, but not when the engine is operating at elevated RPM's, it almost seems safe to assume that it is not wiring harness/ETA related, but more likely caused by a stcky cable or missing spring??

Quote:

Originally Posted by HJHJ VAN EKERT

Jim:
You refer to a "pot" - is this a variable resistor connected to the accelerator pedal or is it inside the ETA?

Could be both! Look for picture of the "Ref Pot" in Menu#24.

Quote:

Originally Posted by HJHJ VAN EKERT

For example, if the ASR light comes on (as in my case) while the car is idling, at a standstill, but not when the engine is operating at elevated RPM's, it almost seems safe to assume that it is not wiring harness/ETA related, but more likely caused by a sticky cable or missing spring??

Don't think so! That's how it starts. Mine started ONLY when I backed up and give the #6 error in the DM.

The mechanical linkage is visible in the back behind the air cleaner. You can visually inspect it but odds are that it's fine. If it's "broke", you will be able to see it.

Read this thread. I too feel that you may have a cable adjustment issue.

http://www.benzworld.org/forums/forums/thread-view.asp?tid=1224135&posts=16

ASR/ETA problem on s600

Your problem may be a faulty signal from th eignition module (this is the RPM signal) It is carried in a COAX cable in the wiring harness and when the foam insulation in the coax 'biodegrades', the signal goes to ground. Take a careful look at the individual wires in the main wiring harnesses goin ginto the 'computer bay', checking the harnesses at the 'hot' locations in the engine bay.

The 4000-4500 RPM cut-out is the normal safety feature of the engine management system--not supposed to rev over that without car moving (need speed signals from the tranny and each wheel to go above that cutoff)