ASR Light - PeachParts Mercedes-Benz Forum

zibsBenz · #1 04-27-2009, 11:46 PM

1994 s320. Lately I've been noticing oily spots on the driveway, so today I decided to give the lower engine and transmission area a degreasing/cleaning to try and identfy were the leaks are originating. Drove the front wheels up on a pair of car ramps and proceeded to spray some degreaser solution and clean up the oily dirty areas. Once done I backed the car off the ramps and attempted to go for a drive. The ASR light came on and the car would barely move no matter how much the accelerator was depressed, the RPM did not increase stayed at 750. Turned the key off and restarted the engine put it in drive and drove for about half a block, ASR light came on again and car would not accelerate. Had to do this restart routine several times to get the car back home. Any Ideas as to what the symptoms are to cause this ASR problem.

mpolli · #2 04-28-2009, 06:15 PM

Was that car affected by the crumbling wiring harnesses? I will guess something has gotten wet. Hopefully it will dry out in time. Hopefully someone else has a better answer.

Arthur Dalton · #3 04-28-2009, 07:51 PM

>

Nope..that is the best one ........

zibsBenz · #4 04-28-2009, 11:55 PM

I'm aware of the wireing harness problems with this model so I tried very hard not to get it wet or diturb, but.
I got the car from my brother inlaw as a gift 8yrs ago. He couldn't tell me if the harness was ever changed. When he owned it and whenever some thing was wrong with the car or it needed its regular maintenance work he simple dropped it off a MB dealear and paid the bill.
I had a look (accessable visable areas)at the wiring harness its not crumbling from what I can see, but areas were wet, I used some compressed air to remove any noticable sitting moisture. Left car in the sun with hood up to dry. This morning it started ok but the belt started to sqeal like crazy, couple of increases in RPM and it stopped squealing and the ASR came on. Turned ignition off and restarted, light was off, idled the car till it warmed up periodically reving it up, ASR did not come on again.....so far. Just another question but would a low brake pedal affect the ASR to come on. I'm due for a rotor change. Last brake pad change rotors were getting down in thickness but still some good life in them. Last week during my tire rotation I also checked and measured the rotors (6months since pad change) and they were .oo5 below minimum now, smooth and evenly worn.

EricSilver · #5 04-29-2009, 12:49 AM

Quote:

Originally Posted by zibsBenz

This morning it started ok but the belt started to sqeal like crazy, couple of increases in RPM and it stopped squealing and the ASR came on. Turned ignition off and restarted, light was off, idled the car till it warmed up periodically reving it up, ASR did not come on again.....so far.

Ah, the mysteries of ASR and the 320 engine.

Check for power steering fluid leak at front seal contributing to belt squeal.

I have intermittent ASR issues when the weather is cold/wet. The most common causes cited here are: voltage regulator, stop light switch, throttle actuator, throttle position switch, and ABS sensors in wheels.

What is confounding is that it does not happen in warm weather. It first occurred nearly two years ago when the temperature was below freezing. Then it started happening when the temps were in the 30's/40's. Then when at or below 50. Now it occasionally occurs below 60. Either A.) some temperature-sensitive component has progressively gotten worse (i.e., coolant temp sensor); or B.) a switch is dirty and gummed up and cold weather causes it to remain stickier and not function properly until warmed up (i.e., stop light switch or throttle position switch); or C.) some electrical connection on or near the engine is affected by heat, behaving well when the engine is warm/hot, and poorly when cold. A & B seem most likely.

If, after I clean and/or replace my stop light switch, the problem persists I'll replace the coolant sensor. If it still occurs, I'll just live with it. It's only an occasional nuisance.

zibsBenz · #6 04-29-2009, 08:17 AM

I've lived with belt squeal for 2yrs but ASR never came on. Changed belt Twice. It occurs on cold or damp or rainy day startups, reving the engine slightly a couple of times gets rid of it. Also notice a quick cherp if accelerating quickly and then when letting off lick when passing another vehicle.

ds190 · #7 04-29-2009, 08:36 AM

I don't have ASR, and did not search my question before posting

ASR is tied into braking and engine management controls.

Can the ASR "system" be disabled w/o affecting driveability?

zibsBenz · #8 04-29-2009, 06:25 PM

Road tested the car today, no ASR light but I notice I now have no AC function, no defrost, fan doesn't come on in defrost mode. The front auxillary fans have not come on either. No blown fuses. Boy do I wish I'd left the engine bay alone, never going to wash it again !!
Any ideas what I should check now.

EricSilver · #9 04-29-2009, 09:59 PM

Quote:

Originally Posted by zibsBenz

Road tested the car today, no ASR light but I notice I now have no AC function, no defrost, fan doesn't come on in defrost mode. The front auxillary fans have not come on either. No blown fuses. Boy do I wish I'd left the engine bay alone, never going to wash it again !!
Any ideas what I should check now.

After washing the engine, how long did you let it run? Letting it get nice and hot should dry out anything that is still wet -- assuming you used water when cleaning.

You can test the electric fans by disconnecting the coolant temperature sensor (if you have the 2-sensor thermostat housing) and then energizing, but not cranking, the ignition. You'll hear the fans come on.

You may also have inadvertently disconnected something. Out of curiosity, how do you determine your fuses are not blown?

zibsBenz · #10 04-29-2009, 10:25 PM

EricSilver
I used compressed air (low pressure)to remove any standing moisture then left car with hood up in the sun, later parked it in the garage with hood open and a large fan directed at the engine compartment....stayed like this over night. Removed all shrouds/plastic covers so air could circulate at wiring during this process.
Today visually checked the wiring and connections and everthing looked very dry.
I took it for a long drive and during that time no climate control functions, or auxilary fans running. Let the car sit and idle and fans did not come on, before when working they would have come on by this time. Checked the fuses by pulling and looking and substituted with new ones.

zibsBenz · #11 05-01-2009, 12:23 AM

Update.....My ASR problem seems to be gone and my auto climate control back in working order......I don't know how. This morning I went about checking all connections for corrosion, moisture etc and all seemed in good order, still nothing worked. By passed the coolant sensors and the aux fans worked. I then pulled the cover off the blower motor and checked connections still nothing. Noticing the area rather dusty I took the compressed air to it and a large amount of black dust came out, fan spun due to the air blast and I noticed a little spark at one of connectors to the blower motor. The key was not in the ignition. I checked the connector and nothing looked fryed, it was clean.
I then proceeded to start the car and once running everything works

. Took it for a long drive everything seems fine and no ASR so far......Gremlins???

deanyel · #12 05-01-2009, 12:32 AM

The probability that your ASR problem is permanently gone is exactly zero.

zibsBenz · #13 05-01-2009, 01:08 AM

deanyel.....I fully realize that but until it appears agian I'm going to enjoy my touring around in this car. Its also going into shop to have its codes read, that may be stored. The check engine light has flashed a couple of times (on for a few seconds) a few months previous to the ASR.