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Ask Lou P. master tech Your Own Question
Lou P. master tech
Lou P. master tech, Mercedes Technician
Category: Mercedes
Satisfied Customers: 4273
Experience:  15 years master certified 100% fix rate and have access to factory radio codes, wiring, and instructions.
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1995 S420 (V8) Vin# SA270495 ASR light is... 1995 S420 (V8)

Customer Question

1995 S420 (V8) Vin# ***** ASR light is...
1995 S420 (V8) Vin# *****
ASR light is on
I am pulling the following codes:
EFP n4/1 Control Unit
Can: No data from EA/CC/ISC N4/1Car is idling up and down and then after a while it will shut offWe have already replaced EGas module(###) ###-####Any ideas
Submitted: 7 months ago.
Category: Mercedes
Expert:  Lou P. master tech replied 7 months ago.

Hello, my name is***** and i will do my best to assist you.I am going over your story now and will reply back soon with some info,thanks!

Expert:  Lou P. master tech replied 7 months ago.

first question comes to mind is , how is the engine wiring harness? the harnesses of these years got brittle and would cause all sorts of issues.

Customer: replied 7 months ago.
Wiring harness looks good...
Here is the whole story:
1. Start Car
2. Idle slowly starts to creep up
3. Then idle starts to surge up and down
4. Cooling fan then starts to come on for very short periods of time and it seems like it is surging too (like the engine)
5. ASR light is on in dashI have already changed e-gas computer and mass air flow
Expert:  Lou P. master tech replied 7 months ago.

ok, asr issues are usually related to a misadjusted throttle cable, a failed throttle body, or poor wiring. inside the throttle body is the same wiring. and it deteriorates and shorts internally, there are videos for rebuilding the throttle body simply by rewiring the wires.

i will not disregard the codes, i will see what the test steps are if any,. do you have the fault code numbers? and what modules you pulled the codes from?

Customer: replied 7 months ago.
no code numbers came up... All codes were pulled from E-GAS(###) ###-####and Traction /ASR
Expert:  Lou P. master tech replied 7 months ago.

i am sorry on a car this ould i wont be able to advise on what to do, at least with the asr, i have not personally had that much experience in the issues.