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Discussion Starter #1 (Edited)
Greetings,

Please help. I would be very grateful.

The issue:

Last night I took the car for a drive (the streets were slightly wet from the rain). As I was coming towards a Stop sign for a left turn, I decided to see if there would be any difference in the handling of the car when I pressed the ASR off switch. When I pressed the button, a steady amber triangle with and exclamation mark sign appeared in the dash, I pressed the gas pedal hard and made my left turn. Well, I didn't notice anything much different after I made the turn so I pressed button again to enable ASR. At less than 500yd ahead I stopped at an intersection to wait for traffic to clear, when it did, I tried to accelerate to go forward but the car wasn't moving. When I looked at my dash I noticed the RPM gauge showing about 600 RPM, I tried to hit the gas again but there was no change in RPM. I turned the keys to the Off position and cranked the car. Again the RPM was steady at 600 but nothing happened when I pressed the gas pedal, then I noticed that the ASR indicator was lit in the dash. Has anyone had this problem before? Where exactly are the ASR components in the car? (By the way I had to drive home with the engine on idle, which was not very far thankfully)


About my car:

1995 C280 with 128K miles. Replaced the OVP relay (which was bad), the spark plug wires (including the boots) and two of the ignition coils. The car has been running well (other than a misfire and a cutting off issue, which was corrected with the replacement of the ignition components listed earlier and the OVP Realy, respectively). I also found that the wiring harness that goes from the transmission to a connector in the front of the driver side had the issue of poor/degraded insulation. I replaced this particular set of wires about two months ago with new ones and they car did run better, however, I have noticed a slight decrease in power weeks before last night's problem but I don't know how much is significant to it since I got the car about four months ago.

Please help :(
 

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2000 E320 4Matic Black on Black - Decked out!
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This seems pretty simple to me.

Did you check to make sure the Accelerator cable is still connected @ the throttle body linkage?

It don't take much force to pop off. Stomping on the gas pedal, if to the floor may have over extended the linkage and popped it right off.

If its not connected you won't get RPM changes, because the throttle body is not reacting to the pedal.
 

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Discussion Starter #3 (Edited)
This seems pretty simple to me.

Did you check to make sure the Accelerator cable is still connected @ the throttle body linkage?

It don't take much force to pop off. Stomping on the gas pedal, if to the floor may have over extended the linkage and popped it right off.

If its not connected you won't get RPM changes, because the throttle body is not reacting to the pedal.
Thanks for your reply. I checked that and there is no problem there.
 

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I assume you tried turning ASR off again and then trying to drive? What does the car do in park/neutral/reverse if you rev it
 

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Discussion Starter #5
I assume you tried turning ASR off again and then trying to drive? What does the car do in park/neutral/reverse if you rev it
When I press the ASR button it doesn't do anything anymore after the problem (whether it be on Parking, Neutral, Reverse, or Drive). If I put the car on Reverse it behaves exactly like a normal car if when you don't press the gas pedal and the same thing happens with drive, 3rd or 2nd.
 

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Discussion Starter #6 (Edited)
Perplexing event

Today, I cranked the car again and decided to press the gas pedal (just curious), and noticed that it was working and the ASR light had disappeared! All this on its own. So, I decided to go for a test drive. It drove fine for a couple of minutes but then the problem came back again, and the ASR light came back On my dash, although now if I pressed the gas pedal all the way it would accelerate to about 1200 RPM.
 

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1995 C220
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Check for error codes. The ASR is traction control(you may have allready new that). I am unfamiliar with the function on this particular car because mine doesnt have that option. But they all basically moniter the wheel speed at each wheel, and when the computer notices a wheel turning at an abnormal speed compared to the rest, depending on the car it will either a. brake that wheel, or b. take power away, or c. a combination of both. Now my parents have a 2000 s class, and I know when we were playing with it in wet weather, you could stomp the pedal to the floor, the light would come on and basically nothing would happen because it simply would not let the throttle body open to accelerate. This sounds exactly like what your car is doing.

Why is it? I would think that there is problem with one of the wheel speed sensors. Have the car scanned for codes and it should reveal which one isnt working. The fancier tools will let you drive the car and show the individual wheel speed at each corner.

Another thing you could try is disconnecting the battery for about 30 minutes to an hour and hook it back up, and see if the computer resets itself. It may or may not. Unlikely but worth a shot. If it is a wheel speed sensor, depending on the car it is either a simple replacement of the sensor if it is not built in to the bearing. Some are built into the bearings and require some dismantling to replace, but not familiar with mercedes so not sure.
 

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Discussion Starter #8 (Edited)
Check for error codes. The ASR is traction control(you may have allready new that). I am unfamiliar with the function on this particular car because mine doesnt have that option. But they all basically moniter the wheel speed at each wheel, and when the computer notices a wheel turning at an abnormal speed compared to the rest, depending on the car it will either a. brake that wheel, or b. take power away, or c. a combination of both. Now my parents have a 2000 s class, and I know when we were playing with it in wet weather, you could stomp the pedal to the floor, the light would come on and basically nothing would happen because it simply would not let the throttle body open to accelerate. This sounds exactly like what your car is doing.

Why is it? I would think that there is problem with one of the wheel speed sensors. Have the car scanned for codes and it should reveal which one isnt working. The fancier tools will let you drive the car and show the individual wheel speed at each corner.

Another thing you could try is disconnecting the battery for about 30 minutes to an hour and hook it back up, and see if the computer resets itself. It may or may not. Unlikely but worth a shot. If it is a wheel speed sensor, depending on the car it is either a simple replacement of the sensor if it is not built in to the bearing. Some are built into the bearings and require some dismantling to replace, but not familiar with mercedes so not sure.
Thanks for your reply, and insight. Unfortunately, I am not getting any codes, only the ASR dash indicator is on. I ordered an ASR module (which is seperate from the ECU (Engine Control Unit) which is the main module), which appears to be the problem. I made this deduction, when I realized that after having the car in parking, if I wait 15 minutes with the engine off, I can press the gas pedal and it works fine, however if I turn the car immediately off and crank it back up and then the gas pedal will not work until the 15 minutes or so have passed. I don't think this problem has to do with the wheel speed sensors since this test I made was when the car was parked and there was no motion at the wheels to sense.

(Based on what I have read, the function of ASR (Acceleration Slip Regulator) or ETS (Electronic Slip Regulator) is to work with ABS by adjusting engine acceleration in order stabilize the car in a situation where poor traction is detected.)

After I replace this module I will be looking at the speed sensors if the problem persists. I'll update on the result. Thanks again.
 

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Keep in mind though, that if whoever plugged in and scanned the car for you did it through the obd2 port under the dash, it may not see all the codes, just engine related. You may need to go to an independant with a better scan tool that can use the connector under the hood and get the more vehicle specific codes. Just a thought. I say this only because for the problem you have I am having a hard time believing that it has not kicked off SOME kind of code, and also because I work at a collision repair shop with a Snap on Modis scan tool which can read through both ports; I can only get engine related stuff through the obd2, and have to go under the hood to scan for stuff like airbags, abs, etc. Most of the tools at oreillys or autozone are obd2 only.
 

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Discussion Starter #10
Keep in mind though, that if whoever plugged in and scanned the car for you did it through the obd2 port under the dash, it may not see all the codes, just engine related. You may need to go to an independant with a better scan tool that can use the connector under the hood and get the more vehicle specific codes. Just a thought. I say this only because for the problem you have I am having a hard time believing that it has not kicked off SOME kind of code, and also because I work at a collision repair shop with a Snap on Modis scan tool which can read through both ports; I can only get engine related stuff through the obd2, and have to go under the hood to scan for stuff like airbags, abs, etc. Most of the tools at oreillys or autozone are obd2 only.
I did not know that there would be a difference between the two ports. I knew there was an ODBII adapter for the Mercedes-proprietary port which would allow the ODBII scan tool to plugged under the hood, and because my car being from '95 only had available 19 pins out of the 32 total that are in that port, I assumed that it wouldn't make a difference. I'll try to get mine plugged there to see if there is a code. Thank again!
 
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