SLK/R170: Acceleration problem
Thread Starter
Junior Member
Joined: Aug 2002
Posts: 28
Likes: 0
From: Dallas, TX
'09 Audi A5
Acceleration problem
I originally put this down to the cruise control having a mad 5 minutes, but it happened again today, under similar circumstances.
Basically, after an hour or so of sustained motorway driving (80-90mph), I pull off onto the ramp to stop at the traffic light. When I set off, there's a long delay of about 4-5 seconds between me pressing the accelerator pedal and the car pulling away. It's difficult to describe, but it's almost like I'm trying to pull away in 3rd gear (it's an auto), but it's definately in first. Once the car is off, the acceleration is still dulled, but less noticable at speed.
The only way to 'reset' it is to stop & start the engine. As far as I can tell, the gears are changing OK and there's nothing interfering with the pedal. No warning lights ever come on, and dis-engaging the ESP makes no difference.
The only way around the problem whilst in motion is to engage the cruise control, which controls the car normally, with the accelration responding as it should.
I called my dealer, who, as usual, didn't really care about any problem I might be having, and offered to book me in for 3 weeks time - very useful considering I've now had 2 cars nearly go into the back of me as they're obviously expecting me to pull away a bit quicker.
Anybody had a similar problem? Is there a 'granny-button' I've pressed by mistake
? I suspect some sort of sensor problem, maybe caused by an overheat somewhere?
Basically, after an hour or so of sustained motorway driving (80-90mph), I pull off onto the ramp to stop at the traffic light. When I set off, there's a long delay of about 4-5 seconds between me pressing the accelerator pedal and the car pulling away. It's difficult to describe, but it's almost like I'm trying to pull away in 3rd gear (it's an auto), but it's definately in first. Once the car is off, the acceleration is still dulled, but less noticable at speed.
The only way to 'reset' it is to stop & start the engine. As far as I can tell, the gears are changing OK and there's nothing interfering with the pedal. No warning lights ever come on, and dis-engaging the ESP makes no difference.
The only way around the problem whilst in motion is to engage the cruise control, which controls the car normally, with the accelration responding as it should.
I called my dealer, who, as usual, didn't really care about any problem I might be having, and offered to book me in for 3 weeks time - very useful considering I've now had 2 cars nearly go into the back of me as they're obviously expecting me to pull away a bit quicker.
Anybody had a similar problem? Is there a 'granny-button' I've pressed by mistake
? I suspect some sort of sensor problem, maybe caused by an overheat somewhere?
Thread Starter
Junior Member
Joined: Aug 2002
Posts: 28
Likes: 0
From: Dallas, TX
'09 Audi A5
Thanks Brian...
THat makes a lot of sense, given that the cruise works fine, and presumably doesn't use the throttle sensor. Although I'll get the dealer to replace it, is the sensor accessable? I just want to make sure there are no loose connections before I hand over my cash to my useless dealer.
Senior Member
Joined: Jul 2007
Posts: 421
Likes: 14
From: Bay Area
2004 E500 CLK320
I originally put this down to the cruise control having a mad 5 minutes, but it happened again today, under similar circumstances.
Basically, after an hour or so of sustained motorway driving (80-90mph), I pull off onto the ramp to stop at the traffic light. When I set off, there's a long delay of about 4-5 seconds between me pressing the accelerator pedal and the car pulling away. It's difficult to describe, but it's almost like I'm trying to pull away in 3rd gear (it's an auto), but it's definately in first. Once the car is off, the acceleration is still dulled, but less noticable at speed.
The only way to 'reset' it is to stop & start the engine. As far as I can tell, the gears are changing OK and there's nothing interfering with the pedal. No warning lights ever come on, and dis-engaging the ESP makes no difference.
The only way around the problem whilst in motion is to engage the cruise control, which controls the car normally, with the accelration responding as it should.
I called my dealer, who, as usual, didn't really care about any problem I might be having, and offered to book me in for 3 weeks time - very useful considering I've now had 2 cars nearly go into the back of me as they're obviously expecting me to pull away a bit quicker.
Anybody had a similar problem? Is there a 'granny-button' I've pressed by mistake ? I suspect some sort of sensor problem, maybe caused by an overheat somewhere?
Basically, after an hour or so of sustained motorway driving (80-90mph), I pull off onto the ramp to stop at the traffic light. When I set off, there's a long delay of about 4-5 seconds between me pressing the accelerator pedal and the car pulling away. It's difficult to describe, but it's almost like I'm trying to pull away in 3rd gear (it's an auto), but it's definately in first. Once the car is off, the acceleration is still dulled, but less noticable at speed.
The only way to 'reset' it is to stop & start the engine. As far as I can tell, the gears are changing OK and there's nothing interfering with the pedal. No warning lights ever come on, and dis-engaging the ESP makes no difference.
The only way around the problem whilst in motion is to engage the cruise control, which controls the car normally, with the accelration responding as it should.
I called my dealer, who, as usual, didn't really care about any problem I might be having, and offered to book me in for 3 weeks time - very useful considering I've now had 2 cars nearly go into the back of me as they're obviously expecting me to pull away a bit quicker.
Anybody had a similar problem? Is there a 'granny-button' I've pressed by mistake
? I suspect some sort of sensor problem, maybe caused by an overheat somewhere?
Thread Starter
Junior Member
Joined: Aug 2002
Posts: 28
Likes: 0
From: Dallas, TX
'09 Audi A5
you know, 8 years is a long time, I've had at least 5 other cars and a wife since then :-)
I vaguely remember it was some kind of sensor problem on the accelerator pedal (as Brian says below), but honestly I'm not 100% certain. It was a quick fix for the dealer though.
Pete
I vaguely remember it was some kind of sensor problem on the accelerator pedal (as Brian says below), but honestly I'm not 100% certain. It was a quick fix for the dealer though.
Pete
Senior Member
Joined: Jul 2007
Posts: 421
Likes: 14
From: Bay Area
2004 E500 CLK320
Thanks Pete. I really appreciate the reply, even after all these years.
I called some local MB dealers, some don't give out part#s but I found one dealer who gave me the part number for the gas/accelerator pedal assembly. The part# is 170-300-0104, for SLK320 automatics. The prices they quoted me ranges from $294 to $348. However, I found an online website that sells it for $184, at http://www.mercedespartscenter.com
I did more research online. The most common fix to this problem is just simply replacing the whole gas pedal assembly. The failing part is probably the accelerator sensor that's built into the pedal assembly. This sensor alone costs about $160 online. I may just as well replace the whole pedal assembly.
I called some local MB dealers, some don't give out part#s but I found one dealer who gave me the part number for the gas/accelerator pedal assembly. The part# is 170-300-0104, for SLK320 automatics. The prices they quoted me ranges from $294 to $348. However, I found an online website that sells it for $184, at http://www.mercedespartscenter.com
I did more research online. The most common fix to this problem is just simply replacing the whole gas pedal assembly. The failing part is probably the accelerator sensor that's built into the pedal assembly. This sensor alone costs about $160 online. I may just as well replace the whole pedal assembly.
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Senior Member
Joined: Jul 2007
Posts: 421
Likes: 14
From: Bay Area
2004 E500 CLK320
I just installed the new gas pedal assembly and the acceleration is back to normal. It took about an hour to do this job. The only thing's holding down the gas pedal to the floor is the 10mm nut and the washer. It's a pain removing the washer since it's tightly nested in the recessed hole. I used to small flat head screw drivers jiggling the washer side to side and popping it upward at the same time. It took me about 20 mins to remove the washer. (Poor MB design). Once the washer is out. The pedal can be removed easily.
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Junior Member
Joined: Jul 2010
Posts: 35
Likes: 0
02 SLK32 AMG, 07 E350 Sport
Wow 8 year old post, with 2 month old reply... Glad I found this thread.
I am having the exact same problem. Restarting the car will restore original pedal response, but only for a while. It is a completely random thing.
Thank you, your posts helped me confirm that a new pedal assembly will solve my problems.
Parts.com has the part for $170 at the time of this post. For those who will find this post in the future having the same problems, navigate to Fuel - Fuey Supply - Pedal Assy.
I am having the exact same problem. Restarting the car will restore original pedal response, but only for a while. It is a completely random thing.
Thank you, your posts helped me confirm that a new pedal assembly will solve my problems.
Parts.com has the part for $170 at the time of this post. For those who will find this post in the future having the same problems, navigate to Fuel - Fuey Supply - Pedal Assy.
Newbie
Joined: Apr 2011
Posts: 4
Likes: 0
ml350 2005
i was driving my ml350 last night and hit a big pot hole and thats when my acceleration on the car started to give me issue it would take a few seconds before it response. So i parked the car turned it off and turnn it back on and the check engine light appeared. Now the car will take like 2 seconds to accelerate. Got home woke up this morning still the same issue. is there anything i can do without seeing my expensive mechanic and if not what should he be telling me
Member
Joined: Sep 2005
Posts: 82
Likes: 2
2014 C250
I'm having the same problem on my wife's 02 320. The car is throwing a P0123 code which is a throttle pedal/position sensor error on my Actron scanner. I'm ordering from parts.com....
BTW: The pedal is a challenge to get out. The 02s have a single 10mm nolt under a plastic cover. The washer under the nut hangs up on the stud making it hard to remove the pedal assembly. A small pry bar under the pedal assembly will help force the pedal up and out.
BTW: The pedal is a challenge to get out. The 02s have a single 10mm nolt under a plastic cover. The washer under the nut hangs up on the stud making it hard to remove the pedal assembly. A small pry bar under the pedal assembly will help force the pedal up and out.
Junior Member
Joined: Nov 2011
Posts: 15
Likes: 0
SLK320
I had the same 2-3sec. acceleration lag from a full stop on my 2001 SLK320, it was intermittant and the check engine light came on. I recorded the codes P0120 and P0173 then erased & made notes, and performed more test drives. the solution seemed to be a throttle valve, or EA throttle pedal module w/B37 sensor and MAF mass air flow sensor, cleaning and checking connectors and MAF no help.
After many drives, notes and info from MB Forums etc.,
I replaced the EA pedal module (Genuine M-B) part no. A 170 300 01 04 and the Mass airflow sensor (Bosch) part no. 0 280 217 515, and 19 test drives and 800 miles later the acceleration is perfect and no CEL repeats. Accelerator module $200.+ $9shpg. from genuinemercedesparts.com an Atlanta, GA. M-B dealership and web store, and the MAF sensor assy., from AutohausAZ.com $180.free shpg.
After many drives, notes and info from MB Forums etc.,
I replaced the EA pedal module (Genuine M-B) part no. A 170 300 01 04 and the Mass airflow sensor (Bosch) part no. 0 280 217 515, and 19 test drives and 800 miles later the acceleration is perfect and no CEL repeats. Accelerator module $200.+ $9shpg. from genuinemercedesparts.com an Atlanta, GA. M-B dealership and web store, and the MAF sensor assy., from AutohausAZ.com $180.free shpg.
Last edited by Ricks170.465; Dec 2, 2011 at 03:14 PM. Reason: add part numbers
Newbie
Joined: Dec 2011
Posts: 3
Likes: 0
From: cebu city Philippines
SLK 230 1997 , BMW e39 1999 , Dodge Durango XLT 2006
i currently have the same problem with my SLK.. I already changed the k40 relay and also the accelerator pedal sensor but still no luck. My car accelerates really slow once i press the gas. My mechanic said that there is no relation with the accelerator pedal Assembly because there is no potentiometer and only cables connecting to the accelerator pedal sensor. Is this true?
He suggests to let me buy a new Computer box because my box is defective due to no Error codes can be read. Is it true that I have to buy a ECM Comp box including the alarm modules etc for it to work is it's second hand?
I'm having a hard time finding one because Ebay usually sells the Box Alone.
Im really having a hard time figuring out what the problem might be. Can anyone please shed light on this matter?.. Thank you very much
He suggests to let me buy a new Computer box because my box is defective due to no Error codes can be read. Is it true that I have to buy a ECM Comp box including the alarm modules etc for it to work is it's second hand?
I'm having a hard time finding one because Ebay usually sells the Box Alone.
Im really having a hard time figuring out what the problem might be. Can anyone please shed light on this matter?.. Thank you very much
Junior Member
Joined: Nov 2011
Posts: 15
Likes: 0
SLK320
My 2001 SLK320 has a EA (electronic accelerator ) with the B37 pedal value sensor and the kick down sensor as part of the accelerator pedal module, no cable. When I was looking into my acceleration lag problem, it seems that I remember older SLK's with a cable from the accelerator pedal to the pedal value sensor in the engine compt. In addition if I understand the system correctly there are 2 potentiometers in the pedal value sensor and 2 in the throttle valve body and they form a feedback loop a primary and secondary (limp home backup) mine would be in the secondary mode with a intermittant acceleration lag from a full stop at idle. a new EA solved my acceleration lag. PS try to look for codes with a OBDII reader. a good parts store should be able to do it for you, I think it would be very rare that one could not read stored codes in the computer
Last edited by Ricks170.465; Dec 7, 2011 at 06:16 AM.
Newbie
Joined: Oct 2015
Posts: 1
Likes: 0
SLK 200 R170 2001
Solved it
I had the same problem and after reading fora and consulting a mechanic I replaced the throttle pedal and the air mass flow sensor, which did not solve it. Then I remembered a problem I had with my other car, which was caused by a dirty air valve housing. I removed part of the air intake system so I could see the air valve and I opened it by hand. Turns out that a mixture of oil and smoke black had built up on the wall of the air valve, causing it to jam. I used a lot of break cleaner and cloth and managed to get it clean again. The car runs way better now, also stationary.
