Bad Throttle Position Sensor?
#26
MBWorld Fanatic!
Thread Starter
The TPS that I'm referring to is the sensor in the Throttle Pedal itself.
It comes as a complete unit (pedal and sensor together) from the dealer.
Keep in mind that when my problem occurred, I had NO throttle - not ever (until turning car off/on). You observe that you do get throttle after a short period of time. I could put the pedal to the floor, and it just limped along. The reason that I suspected the TPS was that when I put the car in Neutral, then pushed the throttle to the floor, the engine just barely accelerated. This eliminates anything having to do with transmission. And, because there was no misfire, I figured that it wouldn't be engine control.
That's not to say that you're not experiencing the same problem. Given your harsh climate, if you carried salt/water in on your boots, and this found its way to the sensor, you could possibly get this type of behavior intermittently, as connections are made/lost.
I don't think that you'll get an error code from the TPS, as I had no CE light, and if the TPS doesn't think that the throttle moved, the ECU will only see an input of "0%" from the TPS - which is a valid input, thus no error code. . . .
As I mentioned above, after replacing the pedal/TPS assembly, my problem never reoccurred. I wish you good luck in finding your problem.
It comes as a complete unit (pedal and sensor together) from the dealer.
Keep in mind that when my problem occurred, I had NO throttle - not ever (until turning car off/on). You observe that you do get throttle after a short period of time. I could put the pedal to the floor, and it just limped along. The reason that I suspected the TPS was that when I put the car in Neutral, then pushed the throttle to the floor, the engine just barely accelerated. This eliminates anything having to do with transmission. And, because there was no misfire, I figured that it wouldn't be engine control.
That's not to say that you're not experiencing the same problem. Given your harsh climate, if you carried salt/water in on your boots, and this found its way to the sensor, you could possibly get this type of behavior intermittently, as connections are made/lost.
I don't think that you'll get an error code from the TPS, as I had no CE light, and if the TPS doesn't think that the throttle moved, the ECU will only see an input of "0%" from the TPS - which is a valid input, thus no error code. . . .
As I mentioned above, after replacing the pedal/TPS assembly, my problem never reoccurred. I wish you good luck in finding your problem.
#27
Super Moderator
Please remember that the throttle sensor has 2 outputs - primary & backup. Both require to fail to give you no response. Only 1 requires to fail to throw a code. I can't understand why you have to buy the whole pedal assembly. In SA we can just buy the sensor & it's still expensive.
#28
MBWorld Fanatic!
Thread Starter
To be honest, Glyn, I didn't see the part - the SA told me that's the way it came. On the work order it's listed as:
"211-300-08-04 Accelerator"
"211-300-08-04 Accelerator"
#29
MBWorld Fanatic!
You missed the other attachment, the one that shows the error codes you might get.
But you should be able to put a voltmeter and push the pedal and see if it's working...
https://mbworld.org/forums/attachmen...tor-error2.pdf
it says they can be read with a 'generic scan tool' ie OBD2 I guess?
but maybe not throw a CEL eh?
Ha...canadian humor ...
Eh?
( I date woman from Wisconsin so I find myself saying that all the time)
As far a jobs in Automation....what kind of Automation?
PM me.
I worked on SCADA systems for Churchill, which falls into the category of
"distribution automation"...like Utilities...
I got a job listing sent to me from Fulsom near Sacramento...there's a dam there, and it's really nice place to live. Send me your email I'll forward it if you have utility experience.
But you should be able to put a voltmeter and push the pedal and see if it's working...
https://mbworld.org/forums/attachmen...tor-error2.pdf
it says they can be read with a 'generic scan tool' ie OBD2 I guess?
but maybe not throw a CEL eh?
Ha...canadian humor ...
Eh?
( I date woman from Wisconsin so I find myself saying that all the time)
As far a jobs in Automation....what kind of Automation?
PM me.
I worked on SCADA systems for Churchill, which falls into the category of
"distribution automation"...like Utilities...
I got a job listing sent to me from Fulsom near Sacramento...there's a dam there, and it's really nice place to live. Send me your email I'll forward it if you have utility experience.
Last edited by C230 Sport Coup; 05-12-2009 at 05:48 PM.
#30
My car (W203 '01 C320) threw a P0120 'TPS Sensor A circuit' via generic innova 3100a OBDII reader. CEL came on. I tried resetting it while driving to no avail.
Last week I did the following:
1. Replace engine air filters with K&N equivalents
2. Sprayed Autozone MAF cleaner directly into intake
3. engine bay and cabin air filters
4. Drove the car on highway for over 30 miles since.
This is dangerous since i've been stuck in middle of intersections w/no power and have almost been sideswiped, so PLEASE advise y'all.
thanks,
Ben
Last week I did the following:
1. Replace engine air filters with K&N equivalents
2. Sprayed Autozone MAF cleaner directly into intake
3. engine bay and cabin air filters
4. Drove the car on highway for over 30 miles since.
This is dangerous since i've been stuck in middle of intersections w/no power and have almost been sideswiped, so PLEASE advise y'all.
thanks,
Ben
Last edited by Rev 2 Liv; 10-29-2011 at 11:38 PM. Reason: corrected OBDII reading
#32
Thank you Glynn.I have thread searched extensively on this issue and looked at the WIS docs you have so graciously provided.
As I am electronic illiterate, could someone please link me to some reference info concerning how to use a voltmeter?
This thread has the most info, specifically AD07.61-P-4000-45L "pedal value sensor, ME-SFI fault code description"
https://mbworld.org/forums/c-class-w...-thread-2.html
As I am electronic illiterate, could someone please link me to some reference info concerning how to use a voltmeter?
This thread has the most info, specifically AD07.61-P-4000-45L "pedal value sensor, ME-SFI fault code description"
https://mbworld.org/forums/c-class-w...-thread-2.html
#33
Hey someone please help. This is a pic of the pedal assembly and i'm having trouble releasing the harness in this cold weather. Do I simply pinch the two ends where the arrows are and lift?
Anyone kind enough to give me a part number for the pedal assembly on a 12/00 production W203 C320.
Thanks so much!
Anyone kind enough to give me a part number for the pedal assembly on a 12/00 production W203 C320.
Thanks so much!
#34
this is the single most useful thread i've found so far with procedures on testing. But i'd really appreciate a part number for throttle pedal assembly for a 12/00 production model.
http://forums.mercedesclub.org.uk/sh...ad.php?t=50319
http://forums.mercedesclub.org.uk/sh...ad.php?t=50319
#35
Strapped in a new pedal assembly today. Took her for a spin. W/new plugs and wires, throttle response was much improved than before. Drove 16 miles.
Erased OBDII code P0120, but the meter still flashes yellow. Will drive again later tonight and update.
Erased OBDII code P0120, but the meter still flashes yellow. Will drive again later tonight and update.
#37
I'm getting an inconsistent failure when I hit the gas on start up sometimes it hesitates and sometimes it works fine. From what I read here and according to the codes after checking it looks like its the TPS any or the MAS any one have an idea where I can get these parts besides the dealer I have an 03 c230 komp
#40
Working on a 2003 Mercedes C240. Same problem acceleration hesitates when pedal is depressed.
had pending code of something to do intake air i will have read the code again. due the high cost of the throttle body and pedal sensor. we have been interested in leaks, while none where found we did find a exhaust leak. The idea that the problem is between the pedal sensor and he electric throttle body is more appealing in the common since train of thought. Thought of replacing the gas pedal assemble to test and see if it is in fact the demon or if it is throttle body.
had pending code of something to do intake air i will have read the code again. due the high cost of the throttle body and pedal sensor. we have been interested in leaks, while none where found we did find a exhaust leak. The idea that the problem is between the pedal sensor and he electric throttle body is more appealing in the common since train of thought. Thought of replacing the gas pedal assemble to test and see if it is in fact the demon or if it is throttle body.
#41
I recently purchased a 97 E320 that needed a new radiator and fan blade. At least that's all I was told was wrong with it. Once I replaced that I thought I was good to go. The car cranks and idles. But, when I give it gas nothing happens at all. I've tried manually under the hood and nothing. Does this sound like the tps sensor is bad?
#42
Super Moderator
I recently purchased a 97 E320 that needed a new radiator and fan blade. At least that's all I was told was wrong with it. Once I replaced that I thought I was good to go. The car cranks and idles. But, when I give it gas nothing happens at all. I've tried manually under the hood and nothing. Does this sound like the tps sensor is bad?
#43
I read the codes today and it said there wasnt any. The check engine light was never on. I tried a reset i found online by turning the car on; pushing the pedal to the floor for 5 sec than turning the car off. After 3 mins of it resetting it worked. Once i got the car on the road the check engine light came on. Thats when it read misfire in cylinder 3 and 4. The car drove fine but i could tell it wasn't giving its all. Also the gauges weren't working. Although they had previously. Im new to mercedes and from what ive read there is a lot of computer interactions with this vehicle. Should a basic tune-up fix the misfire? Could the gauges not work bc of a fuse or it needs to be reset? Im learning as i go. Im just not one to spend a lot of $$ for a mechanic if i can do it myself. Thanks.
#45
I had the same problem. step on gas and it goes no were or takes much longer to build up speed. bought 2 gas pedals and still didn't fix it. I bought CRC Electric Cleaner and sprayed inside the connector of the pedal, throttle, and MAF and also removed and cleaned the throttle put original gas pedal back on. That seemed to fix it. also used MAf cleaner on the MAF. I also have an 03 C240
#47
#48
Super Moderator
You seem to have a CANBus fault then. No stored codes without CEL? CEL only comes on when the number of faults from one location reaches a threshold.
Just trying to diagnose. Does the car start reliably. Start enable interrogates the temp circuit. Can you borrow a pedal assembly from someone?
https://mbworld.org/forums/c-class-w...t-process.html
EDIT. The TPS to ECU is 2 channel so both have to go out for no response.
Just trying to diagnose. Does the car start reliably. Start enable interrogates the temp circuit. Can you borrow a pedal assembly from someone?
https://mbworld.org/forums/c-class-w...t-process.html
EDIT. The TPS to ECU is 2 channel so both have to go out for no response.
Last edited by Glyn M Ruck; 07-01-2015 at 07:15 PM.
#49
I had a very similar problem - stomp the throttle and absolutely nothing
for 3 - 5 seconds.
Mine was a simple vacuum leak I fixed with a 10 cent hose clamp.
I suspect it cleared up when the engine was restarted due to clearing
the short term fuel trims. All the un-metered air entering the intake
was causing the ME to constantly adjust fuel trims because the O2
sensors kept reporting lean condition (extra air with no extra fuel).
I have one of the OBD-II interfaces from o b d diagnostics . com -
I see after clamping that hose down my short term trims are always at 0 now...
FYI I haven't had to use the throttle reset in 4 months or so now...
for 3 - 5 seconds.
Mine was a simple vacuum leak I fixed with a 10 cent hose clamp.
I suspect it cleared up when the engine was restarted due to clearing
the short term fuel trims. All the un-metered air entering the intake
was causing the ME to constantly adjust fuel trims because the O2
sensors kept reporting lean condition (extra air with no extra fuel).
I have one of the OBD-II interfaces from o b d diagnostics . com -
I see after clamping that hose down my short term trims are always at 0 now...
FYI I haven't had to use the throttle reset in 4 months or so now...
#50
do you have vacum diagram for 2004clk500 please sir ? i have this same problem and car is driving me effing crazy. i dont know if i clean the sensor from insde the car or in the engine for the p0120 . i have no ideah were the sensors are located