ASR Headache

[420SEL]

My boss is having trouble with the ASR on his '96 E320 again. I have done searches on this forum and still would like some extra help. In the past few weeks he has had limp home mode triggered on the DonValley Parkway here in Toronto and it scarred the heck out of him (A very busy highway in not so good weather). He had the car into the MB dealer who thought they fixed it only to have it act up again after spending having $1,800.

This is what he has had done (this was over the New Year's Holiday).

-Short test performed
-E-Gas Module replaced (part # 210-545-06-32)
-Lock replaced (part # 004-994-45-45)
-ABS/ASR/ESP/ETS Electrical eletrical test program performed
-Electrrical system test
-ASR Hydraulic test program performed
-control module - ABS/ASR replaced
-control module - perform version coding
-EA/CC/ISC control Module - ENg. with SFI replaced
-under dash cover panel R&R

78792 Diagnostic start test, code retreive 002, 098, 030, P0505

Sounds like alot of stuff to me. I understand this problem is not too unusual, as there have been many posts on it for w210 E-Class cars and some of the w140 S-Class cars. Is this a problem that generally is caused by one fault, or could it be any number of a hundred things that really is hard to diagnose, and then when fixed another thing could trigger it also? I have had no problems on my '95 E420 with the ASR. I would think that MB would have a technical bulletin out on this with the most common fixes available. The problem is not so much with the cost, but how long it took them to diagnose (apparently after they got the codes it took them three days to figure out what to do), and then that it wasn't fixed.

I am hoping for some insight into whether or not this problem should be able to be fixed with a degree of certainty. Is this problem relaly so complicated, or is the dealer missing something? Also, if you have a suggestion for something that has not been tried we're all ears.


Any help can be appreciated. Thanks.

[Kebowers]

It quite possibly is a bad wiring harness on th eelectronic throttle actuator or a bad main wiring harness. The insulation disintegtates on the individual wires inside the plastic bundle cover. So long as nothing shifts OK. Any movemetn and wires begin to touch and short --usually intermittenly at first.


Have them call in regional tech support. They seem to be swapping out good parts in a very expensive manner. Faulty wiring harnesses will give flakey component test results--often indicating 'bad', when the real problem is the wiring harness. When replacing the component does not cure the problem demand the old part be reinstalled since it obviously was not the cause in the first place.

[Behind the Star]

Can you find out what codes were retrieved? That would help a lot. The dealer will tell you and should be able to give you a printout if they are decent at documentation. The most common thing I have seen to cause asr problems is a faulty potentiometer in the throttle actuator. In that case the actuator would have to be replaced. Because i have seen this a number of times hoever, does not mean that is what is wrong. Sometimes intermmitant problems can be impossible to find and part replacement is a neccessary evil, but he may have someone looking at it who does not have a clue.
Brian

[420SEL]

The only info I could get from the dealer was the following for codes retreived:

78792 Diagnostic start test, codes retreive 002, 098, 030, P0505

Thanks

[Behind the Star]

Code 002 is ASR/SPS (N47-1 or ESP/SPS (N47-2) control module.
Code 030 is CAN communication with EA/CC/ISC control module (N4/1), faulty.
098 and PO505 are not valid ASR codes.
This would have to be tested. I have no answer for you.
Brian