ASR problem is back - PeachParts Mercedes-Benz Forum

arif · #1 10-14-2002, 11:38 PM

ASR light comes on and car goes into limp mode; last time this happened had selector switch replaced (after having actuator replaced twice) and problem was fixed.
Also had brake light switch replaced at the time.

Have read all the threads........but was wondering if the running over debris the other day (a folding chair ) on the freeway could have anything to do with this . ls there anything under the car that could have been damaged and may trigger this problem???
any techs can help????? thanks in advance.

Kebowers · #2 10-15-2002, 10:10 PM

What may be causing the problem is a deteriorated engine wiring harness or the wiring harness to the electronic throttle actuator.

The insulation on the individual wires inside the big black jacket turn to a powder, and when jiggled around short out. The computer system doesn't like this and goes into 'limp in' mode. Depending on exactly which wire shorted to what, the ASR computer senses a fault

If the ABS is working OK(no warning light), that rules out a wheel speed sensor. The ASR looks at the steering wheel angle, each rear wheel speed, accelerator position, engine rpm and electronic throttle position. If the measurements don't add up the proper way TILT goes the ASR computer.

Sometimes the steering wheel angle sensor acts up. Try turning the wheel lock to lock and then restarting the car.

Good luck. Electronic throttles cost around $1,000, wiring harnesses lots more.

need2speed · #3 10-16-2002, 10:29 PM

It may not be your ASR at all...when my alternator crapped out last summer, the ASR light came on and car went into "limp home" mode too. The technician said the ASR light does double-duty as a fault indicator for other electrical problems.

Good luck!

arif · #4 10-18-2002, 03:37 PM

thanks for the input.

l also suspect the alternator is crapping out. after 135k miles, its probably at the end of its life .....but the amps check out ok and no battery problem. the ASR trouble only happens once a week or so. .........
did your alt crap out gradually ???

400E · #5 10-18-2002, 07:25 PM

You need to "pull the codes." Only way to track down faults like this.

I don't believe there is a wheel angle sensor in an ASR-only equipped car -- only if you have ESP, which needs to know whether the car is slipping laterally.

arif · #6 02-28-2003, 09:19 PM

pulled code 6.....ldle speed control inoperative...any suggestions????

vcci · #7 03-01-2003, 11:47 AM

i have a very similar problem in my car. i tried having them pull the codes but no luck. my car goes into limp mode at least once a day and the ASR light doesnt come on everytime, it comes on maybeonce for every 7 times the car goes into limp mode. this has been a major pain since getting the car about 2 months ago. if anyone has any suggestions please feel free to share. as for ARIF, i share your pain man. sorry i couldnt offer any advice.

joe p · #8 03-01-2003, 01:06 PM

Ok, 93 140, early ASR, handled by EGAS via can inputs from CISE or LH and powered by BM (base module, sometimes is refered to as "basic module")

I'd look hard at the harness and look hard at EGAS itself, I've had several EGAS units thats were feet up after EA replacement. The assumption is the EA shorted 'em. Run the full pin tests, if you find no faults and the harness loks good, swap in a know good egas. Now part of this process is checking the fuses in the BM, the pins in the fuse sockets will spread, then it loses power to EGAS long enought o flip it out.

Joe