If the accelerator pedal module is malfunctioning, will it ALWAYS throw a code???

The reason a I ask is because the shop said that if the code is not there than that is not the problem. I said well check it anyways!

 

In my experience it never throws a code. Mine didn't, and a number of others here had the same experience. In fact, when mine went (on a 2001 S55), the SA told me that lack of a code was diagnostic of the accel module failing.

 

BTW, the module is a dual potentiometer. Apparently one tells the ECU the throttle position and the other tells the TCU. When they stop tracking in parallel properly, the transmission and engine see different demands and you wind up in fifth when you should be in first.

There doesn't seem to be a code for this condition. If the transmission thinks you're idling, that's ok with it. If the engine thinks you're happy with you're current power output, it's got nothing to diagnose either.

 

PPS.

I sure hope "the shop" is a Mercedes dealer or very qualified (specialist) independent. MB electrical and suspension systems are NOT something to let a general shop tackle. They're very complicated, take specialized equipment (and experience) to diagnose and you don't want a mechanic acquiring these skills on your dime.

 

I'LL DIAGNOSE IT FOR YOU, BUT I'M IN MANASSAS PARK, VIRGINIA. WWW.MARSAUTOGROUP.COM

-MAR-

 

Thanks guys for the input.

Put the new pedal, and the "500" soul is back in the beast

Thank you

 

Great, glad it worked out for you.

Nice that the forum helps arm us with information to protect us from the misinformatrion we sometimes receive from our "PROFESSIONAL DEALERS" we all deal with.

 

Amen!

 

i have a 2000 s 500 and the check engine light came on and the car was sluggish when accelerating like it had no power and it was the mass air flow meter

 

Hey guys,

I have a 2003 CLK320 Cab with 73K on it; it's been driving nicely since I got it aboutt 2k miles ago.

On my way home from work today, I floored it really quick and released it. I mean the total time from looring to releasing was not more than 1 second. At first, I was a little surprised I didn't feel high RPM or response from engine during that 1 sec. But what was more surprising was that after that I noticed it is now lagging in time responding to "any foot pressure" on the gas pedal. So whether I am stopped completely, and about to go or I just slowed down and wanted to give little pressure to accelerate, it would take about 3 secs from the time I press the gas pedal till I see any RPM response. I would press pedal, and I would keep it pressed, and after about 3 secs I would see a response.

This happened every single time I pressed on the gas pedal, in any situation, for the next 6-7 miles of my trip home. I called my mechanic to enquire as to what is broken, and he said right away "stop the car, turn it off, remove the key then reinsert/restart and it should be fine".

Performing his recommendations when I got home proved he was right. I called for more info, and he explained that he has fixed many of those bad electronic pedals, but he normally sees a code thrown when the problem happens. Since I had no check engine light come on, he recommended for me to stop by for him to take a look. But, after I explained to him that the problem started after I quickly "floored/released" the pedal, he said "Ah, this is what caused it". He suggested then not to worry about stopping by, unless problem happens again.

So my question is , is he right, that the quick flooring/releasing of pedal can cause this? or did I just experiene the 1rst sign of an aging pedal that will soon need replacement?

Also does restarting the car (removing key in process) normally fix the problem (at least temporarily)? Or alternatively, does continuing to drive the car will eventually get the car to reset itself and drive normal again? I didn't get that this is the case from reading this thread. It seems that when people experience this they will continue to have this problem till they replace the pedal. So if the latter is true, is it possible I experienced a "glitch" since the problem is fixed now?

If indeed what I experienced is similar to others, and my pedal is just again, I would rather replace it now, instead of having to experience this again while driving (it is annoying when people start getting too close from the back almost hitting you, becuase you are not going in trafic!!).

I appreciate any input, and thanks in advance.

Cheers,
Essam

 

When this happened to me, it was very pronounced and to the verge of stalling. My car threw codes for the MAF and Acceleration Position Sensor. Replaced one then the other and the car is fine now. I would pull the codes to see if there are any pending that won't trigger the CEL just yet.

 

Hello CL500,

Are you saying that even though my check engine light did not come on, that I may have some codes that could be pulled? Thanks.

 

When my pedal module failed there were no codes, and the dealer said that was often the case.

 

CL, Initially, I too thought my car was stalling. It only felt like that till I realized it is simply not responding for 3 secs or so to the pressure on the gas pedal.

BTW, I drove the car again today and all is fine. No CEL, and still no "accelarator pedal problem". So not sure what to make of this. Is the problem gone or am I bound to see this again in the near future???

This really can be dangerous; one example if you are at a busy stop sign junction trying to make a left, and trying to time oncoming cars from the right, to see when you should start going. You think you got it timed right, and suddenly the car does not respond, and goes slowly for 2 or 3 secs!!!

So, if you're saying that codes can sometimes come up but not trigger CEL right away, I will take in for a health check.

Whoover, my mechanic does not work at the dealership but is an MB/BMW specialist with 20 year experience. He stated normally CEL comes on with those. This actually is what surprised him initially. That is why I am interested to konw if codes can be thrown without CEL coming on right away. I will give him a call tomorrow or Monday to clarify.

 

My s430 just had that part replaced.. It was the weirdest thing. Start the engine.. It will not move.. press the gas to the floor. nothing. My indy got the exact part to replace and it is running perfect again.

 

I just did this change on a 2006 s430. I got the parts from www.parts.com for about 185 shipped. The install was easy and took about fifteen minutes. I definitely feel a difference and driveability is greatly improved. The car doesn't feel like a slug anymore. The part number is 220 300 00 04 as printed on the side.


Raj

 

mine has always been a little slow to respond. Nothing as drastic as some of posts here. I just thought it was one of the drawbacks of having a big luxury boat and me trying to floor it. Should the throttle react instantaneously to the pedal

 

Mine was slow to respond before. In fact it felt like there was play in the mechanism as it would do nothing for the first 1/2 inch of pedal travel. Now it responds to very little pressure and seems more quickly. Solved my problem.

Raj

 

I have a similar problem with my 00 S500, occasionally when i put my foot down when im already doing 40 or 50 it takes a bit for it to go oh, downshift, then instead of going straight into gear, it revs like its rev matching up to wherever it wants to be the goes into gear and takes off... The issue doesnt seem to ever happen with ESP off. And its not randomly revving, it revs up then goes into gear... any ideas?

 

does anyone know where i can get this other than the dealership?

 

have one here

https://mbworld.org/forums/s-class-w...sale-w220.html

 

Mine was a major safety issue. The car took off as if it was floored. Good thing I was not in heavy traffic. I had to turn the engine off, and coast off the freeway. After much research, I replaced the pedal assembly, (15 minute no brainer job). Car runs fine now. How do I reset the Codes. It still throws the "O2 Sensor" code. Any ideas?

 

Just ordered this part for my 03 CL600...been wondering what the problem was and now I think I found it! Fingers crossed. I know this is an old thread but thanks to those who contributed for all the help! Would have no clue without you all!

 

Hi guys,

The acceleration in my 2003 S500 was smooth as silk and it felt like the car used to return the favor when accelerating when I brought it 4 months ago. Until I ended up changing the ABC pump, the Alternator and the Harmonic Balancer. Despite all these changes now the engine just seems too tight and when I press on the accelerator, first of all the pedal seems tight and feels like the car is kinda driving on the 4th gear rather than the D or 5th. It feels like the car is straining due to some "tightness" and dont feel the Glide anymore. When I ease up on the accel pedal, it seems like the car slows down faster than it used to before. Also I feel the gas consumption might be a bit too high than normal. I dont think it might be the accelerator pedal but I might be wrong.

Can anyone tell me what might be the issue?? Any help would be appreciated.

 

Hi Ibeforreal,
The acceleration in my 2003 S500 was smooth as silk and it felt like the car used to return the favor when accelerating when I brought it 4 months ago. Until I ended up changing the ABC pump, the Alternator and the Harmonic Balancer. Despite all these changes now the engine just seems too tight and when I press on the accelerator, first of all the pedal seems tight and feels like the car is kinda driving on the 4th gear rather than the D or 5th. It feels like the car is straining due to some "tightness" and dont feel the Glide anymore. When I ease up on the accel pedal, it seems like the car slows down faster than it used to before. Also I feel the gas consumption might be a bit too high than normal.
Did you have the acceleration issue?? Did you change your pedal? There are no error codes showing. Any help would be appreciated.