Which one first? MAF, TPS, CPS?
Thread Starter
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Joined: Dec 2003
Posts: 166
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2005 E55, 2002 CLK55, 2005 SLK350 also a 2009 BMW 335-IX
Which one first? MAF, TPS, CPS?
Hello Folks,
I have a 2002 CLK55 with just 29K on the clock. It has been flawless until now. The car was built in Augst 2001.
About 18 months ago in warm weather the throttle just stopped resonding. I could press on the pedal but there was no response, or a delayed response. The car would idle fine and start up fine, but there was no "go". After a restart all was normal. No CEL and no further trouble.
Well the issue is back this week and it's winter here. If I really hit the pedal it will slow down like it is gas starved or something. Also, I notice that it seems to happen coming off of a corner (the very first time was the same thing). It will continue with the delayed throttle (I mean it takes several seconds to spool up) and then the power returns, but not totally.
It seems like the throttle is in slow motion. It starts and idles fine however and it did light up the CEL, but that went off after a couple of restarts.
I cleaned the MAF today with the CRC spray, and threw in some fuel system cleaner to absorb any water in there, but there is no change. I read that the MAF can go bad over time with no real relation to mileage and all the parts (MAF, TPS, CPS) are orginal, except the plugs and wires.
I can do the labor myself and I am tryng to decide what to replace first. Any hints or suggestions?
Marcus are you out there? Thanks.
I have a 2002 CLK55 with just 29K on the clock. It has been flawless until now. The car was built in Augst 2001.
About 18 months ago in warm weather the throttle just stopped resonding. I could press on the pedal but there was no response, or a delayed response. The car would idle fine and start up fine, but there was no "go". After a restart all was normal. No CEL and no further trouble.
Well the issue is back this week and it's winter here. If I really hit the pedal it will slow down like it is gas starved or something. Also, I notice that it seems to happen coming off of a corner (the very first time was the same thing). It will continue with the delayed throttle (I mean it takes several seconds to spool up) and then the power returns, but not totally.
It seems like the throttle is in slow motion. It starts and idles fine however and it did light up the CEL, but that went off after a couple of restarts.
I cleaned the MAF today with the CRC spray, and threw in some fuel system cleaner to absorb any water in there, but there is no change. I read that the MAF can go bad over time with no real relation to mileage and all the parts (MAF, TPS, CPS) are orginal, except the plugs and wires.
I can do the labor myself and I am tryng to decide what to replace first. Any hints or suggestions?
Marcus are you out there? Thanks.
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Joined: May 2006
Posts: 1,486
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From: San Antonio, Tx
2000 CLK430
It is definitely not the CPS as that part only causes problems with starting the engine and at severe stages it will cause the engine to shut off while driving.
This only leaves the MAF and the TPS. My bet is that the MAF is finally starting to give up. When my MAF starting going out I did not get any CEL's until 6 months after the issue started. I would start with replacing the MAF first if I were you. Some of the symptoms of a bad MAF were just like yours. The car would idle fine and start up without any issues. I had issues when I would slam on the gas for a fast start or to overtake someone on the freeway. As soon as I stomped on the gas it would take forever to speed up at first and then in later stages it would actually bog down REALLY bad. This is when I started getting the CEL light finally. I bought a new MAF on Ebay and that caused me more issues!!
I finally just went down to the dealership and bought a factory MAF and all the symptoms went away. I believe there is a member selling a factory bosch one in the classifieds section. Good luck..
Greg
This only leaves the MAF and the TPS. My bet is that the MAF is finally starting to give up. When my MAF starting going out I did not get any CEL's until 6 months after the issue started. I would start with replacing the MAF first if I were you. Some of the symptoms of a bad MAF were just like yours. The car would idle fine and start up without any issues. I had issues when I would slam on the gas for a fast start or to overtake someone on the freeway. As soon as I stomped on the gas it would take forever to speed up at first and then in later stages it would actually bog down REALLY bad. This is when I started getting the CEL light finally. I bought a new MAF on Ebay and that caused me more issues!!
I finally just went down to the dealership and bought a factory MAF and all the symptoms went away. I believe there is a member selling a factory bosch one in the classifieds section. Good luck..
Greg
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Joined: Oct 2009
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CLK430
The pedal sender and actuator being out of sync would throw a code almost immediately, so that side is not likely the culprit. Additionally, if the CPS was going out the fuel injection would turn off during the failure period, as they are directly related software-wise. That doesn't appear to be its behavior from what you described.
You could measure the MAF or check the latest frames with a scanner, but most likely just replacing it would be the most effective time/cost route. You are going to have to replace it anyway one day...
You could measure the MAF or check the latest frames with a scanner, but most likely just replacing it would be the most effective time/cost route. You are going to have to replace it anyway one day...
Last edited by onlinealias; Dec 18, 2009 at 11:01 AM.
MBWorld Fanatic!
Joined: Apr 2005
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From: SCV SoCal
2002 CLK430
It's just a guess, but I'd dump the codes and then replace the MAF it the codes don't point to something solid. Also, the airbox is properly seated, right? All the way down, all the way around? I had the same results from an improperly seated air box.
Super Member
Joined: Mar 2005
Posts: 932
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From: North of Boston
If I were in Vegas, I'd bet on the MAF. Cleaning will sometimes work but only for a short time. Don't buy a cheap maf that probably comes form China. The install will take about 20 minutes and I agree totally with Marcus about the codes and be sure you seat the airbox first onto the maf housing before lowering the front. Do an adaptive throttle reset also.
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MBWorld Fanatic!
Joined: Aug 2007
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From: The Bay
SL55, C63
Hello Folks,
I have a 2002 CLK55 with just 29K on the clock. It has been flawless until now. The car was built in Augst 2001.
About 18 months ago in warm weather the throttle just stopped resonding. I could press on the pedal but there was no response, or a delayed response. The car would idle fine and start up fine, but there was no "go". After a restart all was normal. No CEL and no further trouble.
Well the issue is back this week and it's winter here. If I really hit the pedal it will slow down like it is gas starved or something. Also, I notice that it seems to happen coming off of a corner (the very first time was the same thing). It will continue with the delayed throttle (I mean it takes several seconds to spool up) and then the power returns, but not totally.
It seems like the throttle is in slow motion. It starts and idles fine however and it did light up the CEL, but that went off after a couple of restarts.
I cleaned the MAF today with the CRC spray, and threw in some fuel system cleaner to absorb any water in there, but there is no change. I read that the MAF can go bad over time with no real relation to mileage and all the parts (MAF, TPS, CPS) are orginal, except the plugs and wires.
I can do the labor myself and I am tryng to decide what to replace first. Any hints or suggestions?
Marcus are you out there? Thanks.
I have a 2002 CLK55 with just 29K on the clock. It has been flawless until now. The car was built in Augst 2001.
About 18 months ago in warm weather the throttle just stopped resonding. I could press on the pedal but there was no response, or a delayed response. The car would idle fine and start up fine, but there was no "go". After a restart all was normal. No CEL and no further trouble.
Well the issue is back this week and it's winter here. If I really hit the pedal it will slow down like it is gas starved or something. Also, I notice that it seems to happen coming off of a corner (the very first time was the same thing). It will continue with the delayed throttle (I mean it takes several seconds to spool up) and then the power returns, but not totally.
It seems like the throttle is in slow motion. It starts and idles fine however and it did light up the CEL, but that went off after a couple of restarts.
I cleaned the MAF today with the CRC spray, and threw in some fuel system cleaner to absorb any water in there, but there is no change. I read that the MAF can go bad over time with no real relation to mileage and all the parts (MAF, TPS, CPS) are orginal, except the plugs and wires.
I can do the labor myself and I am tryng to decide what to replace first. Any hints or suggestions?
Marcus are you out there? Thanks.
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Thread Starter
Member
Joined: Dec 2003
Posts: 166
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2005 E55, 2002 CLK55, 2005 SLK350 also a 2009 BMW 335-IX
Step one... MAF on the way from Autohaus AZ...
Folks,
Thanks for all the help...
The consensus seems to be the MAF, so I will be staring with that.
Based on the age and the tendency for it to go bad at any time, I figure I will start there. The worst case is that I will have a replacement part that I can tuck in with the spare tire for the day when it finally does die (in the middle of nowhere).
If this does not do it, then it will likely be the TPS, AKA accelerator position sensor.
I will post the results of the MAF swap ASAP. Thanks again to all…
Thanks for all the help...
The consensus seems to be the MAF, so I will be staring with that.
Based on the age and the tendency for it to go bad at any time, I figure I will start there. The worst case is that I will have a replacement part that I can tuck in with the spare tire for the day when it finally does die (in the middle of nowhere).
If this does not do it, then it will likely be the TPS, AKA accelerator position sensor.
I will post the results of the MAF swap ASAP. Thanks again to all…
Thread Starter
Member
Joined: Dec 2003
Posts: 166
Likes: 6
2005 E55, 2002 CLK55, 2005 SLK350 also a 2009 BMW 335-IX
The Fix is IN... Thanks!
First, thanks to all for the help here...
OK, so after cleaning the MAF the problem persisted.
Step one was a new MAF which improved the smoothness of the engine idle but did not fix the throttle problem. After the 20 minute MAF replacement (never pay a dealer for that job) the CEL light came solid and threw a P0120 code which points to the TPS.
So back to Autohaus for that part (TPS). After another self-service 20 minute replacement and an ECU reset the CEL is off and the car is running well.
I drove it for about an hour the other day and I guess time will tell if it's really fixed, since now it's cold and snowing where I am and this car never goes out in that kind of weather.
It's possible that the new MAF was not needed, but since it's the original part I don't feel bad about replacing it. I will keep the original as a spare.
What I learned... 1) You guys give good advice. 2) You can do a lot of work yourself and save a boatload of money. 3) Invest in a code reader.
All the best to you and yours...
OK, so after cleaning the MAF the problem persisted.
Step one was a new MAF which improved the smoothness of the engine idle but did not fix the throttle problem. After the 20 minute MAF replacement (never pay a dealer for that job) the CEL light came solid and threw a P0120 code which points to the TPS.
So back to Autohaus for that part (TPS). After another self-service 20 minute replacement and an ECU reset the CEL is off and the car is running well.
I drove it for about an hour the other day and I guess time will tell if it's really fixed, since now it's cold and snowing where I am and this car never goes out in that kind of weather.
It's possible that the new MAF was not needed, but since it's the original part I don't feel bad about replacing it. I will keep the original as a spare.
What I learned... 1) You guys give good advice. 2) You can do a lot of work yourself and save a boatload of money. 3) Invest in a code reader.
All the best to you and yours...
Thread Starter
Member
Joined: Dec 2003
Posts: 166
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2005 E55, 2002 CLK55, 2005 SLK350 also a 2009 BMW 335-IX
No worries...
Greg,
No worries...
The two parts (MAF and TPS) were about $275 total, plus a couple of hours of my time.
It's still a lot less than the delaer would get. And I enjoy learning about and fixing the car.
JM
No worries...
The two parts (MAF and TPS) were about $275 total, plus a couple of hours of my time.
It's still a lot less than the delaer would get. And I enjoy learning about and fixing the car.
JM
Junior Member
Joined: Oct 2009
Posts: 41
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CLK430
We are all so "it's the MAF" so much that we overlooked what really was the problem. 
In our defense, 99% of the time it is the MAF. (However, I did say if the TPS goes out it *will* throw a code immediately. It did. So at least I was right on that part!) 
In our defense, 99% of the time it is the MAF. (However, I did say if the TPS goes out it *will* throw a code immediately. It did. So at least I was right on that part!)
MBWorld Fanatic!
Joined: May 2006
Posts: 1,486
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From: San Antonio, Tx
2000 CLK430
You may be an asset to us after all JK Bro!!
Greg
Thread Starter
Member
Joined: Dec 2003
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2005 E55, 2002 CLK55, 2005 SLK350 also a 2009 BMW 335-IX
Open the hood and find the brake booster near the firewall (driver side). Just forward of that you will see the throttle cable come out of the firewall and end at a small black box screwed into the top of the wheelwell. That's the TPS at the end of that cable. It also has one electical connector attachment.
Junior Member
Joined: Apr 2007
Posts: 39
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From: Chandler, AZ
06 R500 / 03 CLK430 Conv
First, thanks to all for the help here...
OK, so after cleaning the MAF the problem persisted.
Step one was a new MAF which improved the smoothness of the engine idle but did not fix the throttle problem. After the 20 minute MAF replacement (never pay a dealer for that job) the CEL light came solid and threw a P0120 code which points to the TPS.
So back to Autohaus for that part (TPS). After another self-service 20 minute replacement and an ECU reset the CEL is off and the car is running well.
I drove it for about an hour the other day and I guess time will tell if it's really fixed, since now it's cold and snowing where I am and this car never goes out in that kind of weather.
It's possible that the new MAF was not needed, but since it's the original part I don't feel bad about replacing it. I will keep the original as a spare.
What I learned... 1) You guys give good advice. 2) You can do a lot of work yourself and save a boatload of money. 3) Invest in a code reader.
All the best to you and yours...
OK, so after cleaning the MAF the problem persisted.
Step one was a new MAF which improved the smoothness of the engine idle but did not fix the throttle problem. After the 20 minute MAF replacement (never pay a dealer for that job) the CEL light came solid and threw a P0120 code which points to the TPS.
So back to Autohaus for that part (TPS). After another self-service 20 minute replacement and an ECU reset the CEL is off and the car is running well.
I drove it for about an hour the other day and I guess time will tell if it's really fixed, since now it's cold and snowing where I am and this car never goes out in that kind of weather.
It's possible that the new MAF was not needed, but since it's the original part I don't feel bad about replacing it. I will keep the original as a spare.
What I learned... 1) You guys give good advice. 2) You can do a lot of work yourself and save a boatload of money. 3) Invest in a code reader.
All the best to you and yours...
I'm having similar symptoms with my CLK430 convertible. After coming out of a right hand turn, I'll put my foot down quite hard, have good power, and then as I back off slightly it's as if all my power disappears. Then whenever I press the accelerator pedal after that, they'll be a very delayed response. For instance, when I pull away from the lights, they'll be a 3 - 4 second delay between me pushing the pedal, even right to the floor, before the car slowly moves away. Everything goes back to normal once I restart the car. No CEL ever.
My question is, is your car still running ok after changing the TPS? I've read many posts suggesting the MAF sensor could be the culprit, but I don't want to replace the MAF if not needed.
Just to confuse the issue more, just lately the car hasn't seemed so responsive off the line under normal circumstances, so I tried some MAF cleaner, and it did seem to noticeable help that symptom, but not the VERY delayed response after a right hand turn.
Thanks in advance.
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Joined: Dec 2003
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2005 E55, 2002 CLK55, 2005 SLK350 also a 2009 BMW 335-IX
I say TPS...
Y2...
Yes, I would put my bet on the TPS... After the fix my car runs perfectly.
The right hand turn thing is very similar to what I had. As you can see from the thread history I changed both the TPS and the MAF, with the MAF being done first. It tuns out that the MAF was not needed. However, depending on the age/milage of the car, you may want to change that MAF anyway just to be sure. I hear they do not age well.
Read this entire thread and you will see that you need to have the car scanned for codes. The code I had pointed directly to the TPS.
Best of luck.
Yes, I would put my bet on the TPS... After the fix my car runs perfectly.
The right hand turn thing is very similar to what I had. As you can see from the thread history I changed both the TPS and the MAF, with the MAF being done first. It tuns out that the MAF was not needed. However, depending on the age/milage of the car, you may want to change that MAF anyway just to be sure. I hear they do not age well.
Read this entire thread and you will see that you need to have the car scanned for codes. The code I had pointed directly to the TPS.
Best of luck.
Last edited by HighEndOne; Feb 22, 2010 at 01:28 PM.
Junior Member
Joined: Apr 2007
Posts: 39
Likes: 0
From: Chandler, AZ
06 R500 / 03 CLK430 Conv
Y2...
Yes, I would put my bet on the TPS... After the fix my car runs perfectly.
The right hand turn thing is very similar to what I had. As you can see from the thread history I changed both the TPS and the MAF, with the MAF being done first. It tuns out that the MAF was not needed. However, depending on the age/milage of the car, you may want to change that MAF anyway just to be sure. I hear they do not age well.
Read this entire thread and you will see that you need to have the car scanned for codes. The code I had pointed directly to the TPS.
Best of luck.
Yes, I would put my bet on the TPS... After the fix my car runs perfectly.
The right hand turn thing is very similar to what I had. As you can see from the thread history I changed both the TPS and the MAF, with the MAF being done first. It tuns out that the MAF was not needed. However, depending on the age/milage of the car, you may want to change that MAF anyway just to be sure. I hear they do not age well.
Read this entire thread and you will see that you need to have the car scanned for codes. The code I had pointed directly to the TPS.
Best of luck.
Thread Starter
Member
Joined: Dec 2003
Posts: 166
Likes: 6
2005 E55, 2002 CLK55, 2005 SLK350 also a 2009 BMW 335-IX
You'll have to call them... that's what I did...
Right... I did not find it on the site there at AutohausAZ either.
Call them on the phone and tell them what you need and they will fix you up ASAP.
Call them on the phone and tell them what you need and they will fix you up ASAP.
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Joined: Oct 2010
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clk 430=sold Current=2006 E55 AMG
Cant floor the pedal
just purchased a 01 clk 430 with 100k on the clock. new to the mercedes scene. the first time i floored the car the power dropped. i then had a delayed pedal. not a normal delay. a delay up to 5 seconds. a dangerous delay espicially because i was in brooklyn where driving slow can kill you. the car would eventually respond to the pedal but in a reduced power. i thought it was limp mode but the delay would make drinving to a service station dangerous. after reading some of the forums here i tried changing the mass air. i used a bosch. no luck. also while driving at highway speeds the abs and esp lights came on. happened twice but they go away after one key cycle. another time i used the tiptronic shifter and got the rpm's up high and the check engine light came on and i was not running on all 8 cylinders. i know its alot of info but just wanted to be as descriptive as possible. until i cycled the key. very confused on it might be and cannot afford a dealer to fix.hope someone has some good info for me. thanks in advance
Thread Starter
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Joined: Dec 2003
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2005 E55, 2002 CLK55, 2005 SLK350 also a 2009 BMW 335-IX
I agree...
I agree with Marcus... Get the codes first if you can. Barring that, my bet is on the Throttle Position Sensor at the end of the mechanical throttle cable. What you describe is the same issue I had. The new MAF did not fix it for me. It should be an easy fix.
MBWorld Fanatic!
Joined: May 2006
Posts: 1,486
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From: San Antonio, Tx
2000 CLK430
Make sure to take it to Autozone for a free scan instead of your local dealer. They will also give you a print out that you can post, this will help us get closer to the real issue.
