ASR Light 1994 S420
 

Dear Expert,
My car ASR light comes (yellow light, not RED one) up and the car goes to the limp mode. The service engine is also on and the faulty code 6 (Idle speed control inoperative, test electronic accelerator). I have to turn off the car and restart again, sometimes it happens 3-4 times in 5 minutes. The car is about 70K miles or 116k km.
After search for ASR light, especially reading Jim webpage I have the feeling that the Electronic Throttle Actuator is worn out.
I have changed the harness and stop lamp switch but it does not seem to help. I talked to a MB dealer in the part department and he gave me the price of the piece is CAN $2000.00. Pretty expensive eh? I also asked him whether you sell this part alot? He said at least in one year, he did not sell any (checked from his computer).
The question I want to ask is: Is this ETA the problem? or MAF Sensor or the rear speed sensors? (2 rear speed sensors each one is $311.00).

Any help would be much appreciated.

First check is tire sizing/ equal PSI

I will first check the MAF wiring harness. Also it could be ETA or MAF Sensor or both in rare cases.

You need to have the codes read from the EA/CC/ISC computer.

Also look at Arthur D's post on tire circumference, even tires 1/4" shorter on the rear can create problems.

http://v12uberalles.com/MAF_rewire.htm

http://v12uberalles.com/throttle_actuator_rewire.htm

Dear Friends/Experts,

I would like to update all of you about my ASR light status.
A week ago (Tuesday last week), after a raining day, I went home after work
my car went to limp mode for about 10 times in busy Ottawa, Canada downtown. I was so shameful. I let the car running for about 15 minutes then be able to drive home. I would guess the electrical short somewhere in the ETA, so I decide to open this up... and see what is inside. When this ETA is opened, I see all the wires insulation (11 of them) are in such bad shape crack, oxide (change color to green), when I touch them, they just turn to dust. All the wires are garbage from the IC board to the connector (about 2 meters or 6 feet long). So I just replace all the wires and the car seems to be OK now. I'm waiting for another raining day to see whether it will happen again or not (I hope not).
If some one's ASR light on and go to limp mode, I would suggest you open the wire bundle cover (by cutting it along the wire) to inspect the wire insulation inside before you open ETA (open the ETA is not an easy job).

I would like to thank all of the friends/experts who made all the ASR problem information accessible and this is the best forum I ever learn.

New update:
After 2 raining days, my car works perfectly.
This means the wiring of the ETA was problem in my case.
Not all problem of the ETA is wiring, check Jim webpage, alot of information there.

Congrats dinh . . . your repair of the 'biodegrable' wires on your ETA is truly amazing.

Glad you got it fixed and I'm sure you're extremely :pleased:!

Hi All,

After I read the information on Jim's webpage and the web, it can be two possibilities: wire insulation and/or the reference potentiometer of the ETA. I just rewire to see whether it helps. I also have plan B to buy the new/rebuilt ETA. After google the web to see the availability/price. One company seems to be very good knowledge of the ETA and it is: http://www.jaytanindustriesinc.com/MercedesBenzTB.htm
I ask the guys how they rebuilt, here is what they email me:

Hi-Hi, Mr. Tran,

Our remanufacturing process,concentrates on four distinct areas to insure you are
purchasing a,"AAA" unit in both quality and value.

1. POTENTIONOMETERS "A" & "B"
a. The values of each of the four black traces on each potentiometer must
equal a pre set value.
b. Example: if potentiometer "A" value is x and "B" value is y then the addition of
the two must equal the value y. "A" tells the ECU how much the throttle plate
is OPEN "B" tells the ECU how much the throttle plate is CLOSED.
2. STEPPER MOTOR
a. The integrity of the motor to actuate movement of the throttle plate.
3. ELECTRONICS
a. Ribbon cable, IC board and wiring harness for opens, shorts and
potentiometer weakness failures.
b. Throttle valve switch which confirms with the ECU, the open or closed position
of the throttle plate.

4 MECHANICAL
a. Linkage, bearings, throttle plate and shaft for binding, sticking and hesitation

Finally, we make the unit look pretty. Is pretty a good word for an auto part?

Each of the four areas are certified OK, repaired or replaced as required.
The electronic throttle body is warranted for 2 years no mileage limit.

Please, feel free to contact us with any further questions or needed assistance which we may extend to you, our client.

Terry O'Connor

I hope the information that I post would help any one who has the same problem as I do.

Cheers,

good price..?
 

I looked at the website and their prices are a lot better than I was quoted via Beckmann. They have my ETA's now and have not heard anything yet. If my units are both shot, I will pay for the testing and just get a set from these people. Iam talking 2450$ or 800$ for the same thing. What do you think Jim..?

Tnx for sharing the new site for Fuel Dist and ETAs.

lesrrt, I guess you can only know after you try their ETAs. Let us know. . .