1992 500SL ASR Problem

I started having a problem with the ASR system on a 1992 500SL. I was driving on the highway when the ASR sensor light came on and the car defaulted to a "limp home mode": The engine output power was reduced and I was able to make almost home; after exiting the highway and reducing speed a red light, the battery light came on, and the car completely stalled completely. I restarted the car and the ASR light was off and the car drove normally home.

The local Mercedes shop I use (not a dealer) replace two motors relating to the ASR system: part # 0005453165 -$ 1,500 Parts & Labor. The car was running fine for two months then the ASR problem returned. The repair shop then replaced the ASR sending unit: part # 0005401417 -$ 720.00 Parts & Labor.

Days after the sending unit was replaced the ASR problem continued to occur sporadically. The shop then told me it was the main computer causing the problem, the installed the electrical accelerating unit: part # 1295450132 - $ 2,160 Parts & Labor. In the hopes that the computer would resolve the problem I agreed to the cost. After picking up the car and driving out of the repair shop for a mile the ASR problem returned. I called the shop and returned the car, told them to remove the new computer since it did not resolve the problem.

The original electrical accelerating unit was reinstalled and I was credited for the cost of new computer module. The over voltage protection relay was also tested with a new unit but the problem persisted.

Without any other repair or testing, the owner of the repair shop told me he drove the car during the week without the ASR triggering once. I picked up the car on Friday, March 4, 2003 and a mile from the repair shop the ASR console light came on, the car began the ASR “limp home mode” process; reducing motor output power and when the car speed is reduced below a specific speed,20-25 mph, the battery light comes on, and the car completely stalls. This happened five times before I was able to make it home - I have to turn the car off, restart the car the light goes off, few minutes later the light comes on again and I have to through the same process to restart the car.

I don’t believe the repair ship did a thing during the time the car was at the shop; they also informed me that the ASR module was only install in the SL for two years 91-92 and then discontinued, and that Mercedes has very little technical information on repair procedure for the ASR in this model year. I know that that’s a lie; I’ve seen the ASR system on all SL since 1992.

I think that they either now know what is causing the problem and realized they changed parts arbitrarily and don’t want to honor the repair warranty by installing the correct parts, or they don’t have the technical expertise to isolate the problem: They changed unnecessary parts at will in the hopes that one of the parts will resolve the ASR problem.

So far I’ve spent over $ 2,220 in parts & labor and the ASR problem is the same as the first time I took the car to the shop. I am temped to take the car to an authorized dealer for repair, but I think the shop should fix the problem or refund me for the work I’ve paid to date. I am taking the car back to them on Monday.

I posted the above in the SL forum, and I received replies indicating the problem may lie with the wiring harness; probably another expensive pieces of hardware.

Have your come across an ASR problem system similar to mine?, and why would the battery light be an issue with the ASR system? Could it be a battery, alternator voltage problem?

Any information could you provide would be greatly appreciated.

[Gilly]

It could be related to low voltage. If the vehicle system voltage drops too low, the ASR system could go into a limp-home mode.
Did they ever check any of the affected computers for trouble codes? Usually the system going into limp-home should trigger a trouble code of some sort.
One curious thing I can't quite resolve is why the car would restart after stalling if it's related to low voltage, but it's possible I'm sure. I certainly would pay to do a simple cell and load test of the battery and do a test of the alternator output. I would test it with a voltmeter on the car for about 1/2 hour to see if it drops suddenly at any time.

Gilly

[ILUVMILS]

Hi jrodnar, you say that you're "tempted to take the car to an authorized dealer for repair". You SHOULD be! You need to find out what trouble codes are in the control unit, as Gilly says. This is important. The symptoms you describe may be caused by several things. Give us some more information.

Thank you for your prompt replies, I will advise the repair shop of your evaluations & testing procedures they should have done from the beginning, and will keep you updated with the results.

I have a bad feeling the repair shop is jerking me around on this problem, and are not being forthcoming as to the diagnostic procedures, if any, they’ve were suppose to make prior to changing expensive part at will.

I believe they have discovered their mistake and don’t want to incur additional cost in correcting the ASR problem. But one way or another they will either repair the problem to my satisfaction or refund me for repair cost I’ve incurred so far.

Update:

Finally the problem with the ASR has been resolved.

The shop diagnosed the components listed below with no success:

Over voltage Protection Relay
Neutral Safety Switch
Stop Light Switch
Crank Sensor
Electrical Accelerating Unit Computer
ASR sending unit
Alternator Test
Battery Test
ASR wiring harness

The problem was finally pinpointed to the ASR Motors: Part # 0005453165, they were replaced with new units, but it seems that the new motors were defective, the shop replaced the motors with a new set and the problem has not occurred. The cost was under warranty.

One of Sherlockian quotations seems appropriate to my problem:

We must fall back upon the old axiom that when all other contingencies fail, whatever remains, however improbable, must be the truth.

Hope this helps other with similar ASR problems.

Regards,

JR

[junmuntuerto@ya]

hi,

we followed the same procedure described in your article and changed the ASR Motors: Part # 005453165 but the problem still persisted. the ASR sensor light did not come out but the engine output power was still reduced. i have to step on the accelerator to accelerate faster but it's
hard on the accelerator. what do you think is the problem?

[cool]

kindly set a new thread for your inquiry and give full details on what happen first before you decided to change the motor part, is this motor part the electronic throttle actuator ?

[LeaUK]

Take a read of Justin's post regarding ASR issues and rebuilding the units. Electronic Accelerator (EA) - Who's got the best price?

Many cars are affected by insulation breakdown and NOT the ETA units. Also, the ETA can often be rebuilt using new wiring looms.
http://v12uberalles.com/throttle_actuator_rewire.htm

http://pages.prodigy.net/jforgione/MB_asr.html

http://www.baxnet.net/merc/eta/ta-diags.htm

My issue resolved
ASR problem resolved - by 4 cable ties

These are the Key posts regarding ASR issues on S500s and SLs

Hope this helps
Lea

[cmartin@cuttone]

i have had this problem twice on my '91. i would say 99% it's the throtle actuator. expensive part, but not much labor involved.

[LeaUK]

That's a brave post as >>% of forum members discover it's the ETA loom or loom supplying the ETA..which can be rebuilt.

[bennyhana]

i can't believe that some one else is having the exact same trouble as i am. The trouble seems an exact duplicate of mine with one exception. If i warm the car up for about 10-15 min it runs great but if i try to drive it cold it will only go about a block untill the asr light comes on and the engine fails. My mechanic is looking for a throttle body part # 005453165 but canot find a good used one. Does this sound like the right solution to the trouble and if so do you know where to get a good used one.
thank you for any help

Originally Posted by jrodnar

i started having a problem with the asr system on a 1992 500sl. I was driving on the highway when the asr sensor light came on and the car defaulted to a "limp home mode": The engine output power was reduced and i was able to make almost home; after exiting the highway and reducing speed a red light, the battery light came on, and the car completely stalled completely. I restarted the car and the asr light was off and the car drove normally home.

The local mercedes shop i use (not a dealer) replace two motors relating to the asr system: Part # 0005453165 -$ 1,500 parts & labor. The car was running fine for two months then the asr problem returned. The repair shop then replaced the asr sending unit: Part # 0005401417 -$ 720.00 parts & labor.

Days after the sending unit was replaced the asr problem continued to occur sporadically. The shop then told me it was the main computer causing the problem, the installed the electrical accelerating unit: Part # 1295450132 - $ 2,160 parts & labor. In the hopes that the computer would resolve the problem i agreed to the cost. After picking up the car and driving out of the repair shop for a mile the asr problem returned. I called the shop and returned the car, told them to remove the new computer since it did not resolve the problem.

The original electrical accelerating unit was reinstalled and i was credited for the cost of new computer module. The over voltage protection relay was also tested with a new unit but the problem persisted.

Without any other repair or testing, the owner of the repair shop told me he drove the car during the week without the asr triggering once. I picked up the car on friday, march 4, 2003 and a mile from the repair shop the asr console light came on, the car began the asr “limp home mode” process; reducing motor output power and when the car speed is reduced below a specific speed,20-25 mph, the battery light comes on, and the car completely stalls. This happened five times before i was able to make it home - i have to turn the car off, restart the car the light goes off, few minutes later the light comes on again and i have to through the same process to restart the car.

I don’t believe the repair ship did a thing during the time the car was at the shop; they also informed me that the asr module was only install in the sl for two years 91-92 and then discontinued, and that mercedes has very little technical information on repair procedure for the asr in this model year. I know that that’s a lie; i’ve seen the asr system on all sl since 1992.

I think that they either now know what is causing the problem and realized they changed parts arbitrarily and don’t want to honor the repair warranty by installing the correct parts, or they don’t have the technical expertise to isolate the problem: They changed unnecessary parts at will in the hopes that one of the parts will resolve the asr problem.

So far i’ve spent over $ 2,220 in parts & labor and the asr problem is the same as the first time i took the car to the shop. I am temped to take the car to an authorized dealer for repair, but i think the shop should fix the problem or refund me for the work i’ve paid to date. I am taking the car back to them on monday.

I posted the above in the sl forum, and i received replies indicating the problem may lie with the wiring harness; probably another expensive pieces of hardware.

Have your come across an asr problem system similar to mine?, and why would the battery light be an issue with the asr system? Could it be a battery, alternator voltage problem?

Any information could you provide would be greatly appreciated.

[Hai]

Originally Posted by junmuntuerto@ya

hi,

we followed the same procedure described in your article and changed the ASR Motors: Part # 005453165 but the problem still persisted. the ASR sensor light did not come out but the engine output power was still reduced. i have to step on the accelerator to accelerate faster but it's
hard on the accelerator. what do you think is the problem?

Hey, i have a same problem, can you see the above video tns tell me if your problem was a same or similar?
https://youtube.com/shorts/YmKbVwW2rcE