I have a 92 300 TD wagon with 106,000 3.0 and nave a Asr light which comes on mainly when my wife drives the car. It will go to 2/3 power and lug the rpm's from 0 to 3000 while it is on. If you stop the car it will kill the motor and if you turn the key off to restart it resets the light. It may come back on or it may take a few miles or not come back on at all that trip. The dealer said that it can not check the car unless the light remains on. I have replaced the overload proctection relay, & have done the elec.testing inspection prodedures steps 1.0 3.0 3.3 4.0 4.1 which have all tested out fine hot or cold hope someone can help. Thanks Douglas

I have read on another list that this constellation of symptoms in a gasoline engine may be related to a malfunctioning potentiometer in the throttle actuator. I don't know if this applies in any way to a diesel engine, however.

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'93 400E

On this car, I would suspect the brake light switch or the P/N safety switch... I would check and replace the faulty one or both.

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Benzmac:
Donnie Drummonds
1991 GMC Syclone
ASE CERTIFIED MASTER AUTO TECHNICIAN
SERVICE MANAGER FOR 14 BAY FACILITY
MERCEDES SPECIALIST 8 YRS
PARTNER IN MERCEDESSHOP.COM

The first step is to test the fault codes. This can be done with simple instruments on models till 94.

I don't know what test steps you did, the numbers don't mean anything without more info. The tests done should be based on what the self diagnostics reveal.

Fault codes aren't possible on ASR/ABS systems on these cars as the computers don't have any MEMORY. Only cars with Electronic fuel injection have traction control systems w/readable computers. Diesels never had ASR but started with ASD & now ETS. If the car is a 300TE then the accelerator potientiomer is the most common failure on M103.

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MERCEDES BENZ MASTER GUILD TECHNICIAN
ASE MASTER TECHNICIAN
27 YEARS DEALER M.B. Shopforeman
190E 2.3 ITS RACECAR
1986 190E 16V

I will have to check on that no availability comment. The ASR/ABS controllers are not 25 pin controllers, so they can't be tested with the Bosch LED Tester. I have never seen a 35 pin Bosch controller without at least impulse code capabilities. How else would you test them.

All Bosch ABS that I have seen either test with the LED tester or have self-diagnostics.

Sometimes we hope that MB would design systems so that we can figure them out but not always! Since I've had to repair many of these cars with ASR & "CIS", I can tell you that a pin-by-pin test w/fault present is the only way to diagnose. Since the system only acts once in a while you probably wont find fault. Many times at dealer we would install potientiomer for test driving. And since you've done pin-by-pin testing already & haven't found fault this is the most likely failed part. Sometimes the throttle actuator causes the same problem. The actuator is simular to newer throttle actuator on the HFM & LH engines, we all know how often they fail.

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MERCEDES BENZ MASTER GUILD TECHNICIAN
ASE MASTER TECHNICIAN
27 YEARS DEALER M.B. Shopforeman
190E 2.3 ITS RACECAR
1986 190E 16V

[This message has been edited by M.B.DOC (edited 07-16-2000).]