Solarman2005

New hear but great site. I have 02 C32 with no mods. Up till now car has no problems. 2nd hand to me. 200000km

Last night in parking lot sat idling for 30 min or so. Then I feel a little shudder in the engine. I turn off the radio and the engine is at idle and surging!!!! no engine lights on at all. I go for drive and still the same.
Shifting how ever seems like its is not smooth and a little jerky like the tranny is shifting at the wrong points.
An am fairly mechanical so I think air fiters no they are clean. Then may be a stick TBS remove it and it is sealed but butter fly moves fine. reinstall and still the same. Disconnect the battery and still the same.

Helppppp please car is drivable but what is wrong it was awsome till I sat idleing what did i screw up hear??
Please any one

mikekuriger

You may have to suffer until the CE light comes on.

Miniac

Could be a vacuum leak ,dirty map sensor, bad throttle body or crank position sensor. Hopefully a cel pops on soon show you will know which part is causing the problem.

macbryanie

I had a rough idle and ride; in command unit go to AUX then press mute + 1 and 3 together. In the menu that pops up check the running voltage. My fix was the alternator going out. It didn't throw a cel. Hope this helps to eliminate one possibility. Otherwise perhaps the CPS...

Gramma_Benz

Go and get your codes puled. You can still have engine codes leading you to the problem without a CEL.

Sounds like a Throttle body issue to me.

Good Luck!

Solarman2005

Ahhhh So even tho I have an issue i can`t decifer the problem till the check engine light is lit?
My gut say`s the throttle body.
I say this because my Yukon Denali had similar issues.
Rough ideling and poor shifting and since they are both electronically controlled transmission. The truck got a TPS sensor and the problem went away!!! I just dont want to throw money away!!
The car has no problems starting. and runs better cold 5-10 minutes later the surge!!! The Alternator is new 3 months ago and voltage is fine. As for vacume leak I do not hear any air hissing. Now where is the map sensor located as well as the CPS? what is the sensor under the TB near the tranny and engine connection? TPS ?

Thanks to all so far for this newbie in Ontario Canada

Gramma_Benz

No, you can still pull engine codes even though you do not have a Check Engine Light. Pull them and that will point you in the right direction.

Solarman2005

Well took her to my buddies shop today. Ran the codes found nothing!! played with it for a bit then the surging stopped and ran smooth like new!!! shut the car off and restarted it and surging started again and rpm ramped up to 4K then down. Now the CEL poped up Pulled the code P0120 Pedal sensor problems.

I googled the problem and searched the forums and it appears there are many fixes what is my best bet in reagrds to a repair?
TB?
pedal sensor?

Any adice please

Gramma_Benz

try the pedal sensor first, it's the cheapest...and cross your fingers that it's the problem.

Solarman2005

Thanks man is it easy to change and ball park price?

Solarman2005

Update today is after I took the peadal out last night. I went out next morning and hooked it up. car ran great no ESP light so I let her warm up and then drive for a coffee 15 min later home and running like new CEL is still on. I shut off the car and restart it and the ESP light is on and car runs like a terd and in limp mode!!! I priced the pedal here in Ontario and Stealership wants $308.70 Cdn do you guys and girls think this is really my problem?

Solarman2005

Well update #2 I called my MB dude in Toronto and brought him up to speed on my situation. He said no Way P0120 is the TB. So I take it off and look at it. Upon unplugging the harness I think some one has been in there i had to break the plug since there was brown glue of somesort holding the rubber skin over the end cover of the TB. I had to cut the rubber skin off. 30 Min later I get the back off and clean the gears and tiny little contact with 2000 grit sand paper, put it togeather and the car runs great. on off,on off it appears good. So I drive for 20 min or so and still good, come home turn it off and then on and now the CEL has gone out!!!! have i fixed it??
I dont think so a few hours later and a few more erands to run, the surge returns if I shut off the car and restart it goes away. if I touch the gas the rmp climb then stay there when my foot is off the gass and then slowly comes down to lidle. No CEL right now. What do I do? buy the TPS or the TB? I know buy both!!! does anyone have a stock TB they can sell me from there conversion? what about a gas pedal???

Gramma_Benz

Make sure you got ALL your codes read. I have a code reader and when I had problems, my mechanic's code reader was able to pull some hidden stored codes that I couldn't see.

A Throttle body is going to cost you waaaaay more than a gas pedal. PLus, if I was replacing it, I wouldn't trust a used throttle body, you could just end up having the same problems.

In the meantime, if your car is acting up, do a throttle body reset and that should at least get you on the road and running again temporarily.
Unplug the harness that connects to the throttle body. Wait for one minute and reconnect. Then go and turn the ignition to position two, you will hear the TB whirring. Wait one more minute, then start the car.

Solarman2005

Thanks for the help Granny! I would assume you agree with my diagnostics and would do the peadal 1st due to the costing. I thought someones used TB only if they did an upgrade to a larger one it probably works .

FrankW

Throttle positional sensor on the gas pedal. You need to replace it. Look around for cheaper price online.

Getmercedesparts or rmeuropean have good prices.

johnng117

You really need to have it plugged into the STAR to have the code read to confirm anything.

Solarman2005

Well team got my car back from my repair man. What a run around!!! First of all bought a fellow forum members used TB and gas pedal assy, install and test no luck!!!!
limp the car to MB dealer scan check now they say need TB $2200 plus tax.
F that TB is good I am told.
Limp the car home wait till the next morning and drive the car to Toronto for my garage Euromotion to repair.
Next day he calls me and says he has trouble shot the car and I need a ECU ( no voltage to TB)
He gets a used ECU from C240 and replace board level components and retries.........
no luck need ECU from C32
2 weeks later I get ECU from 02 SLK32 used from a bone yard he gets ECU reprogramned and installed and turn key and the bictch runs. He test it for awaile and performs a road test and warm restart.
I go to Pick up car 6 hours labour scan and enviro fees and ECU program with 13%tax $900
I pay and drive car home and feels good. Only problem is off the line the shift point are slow and the kick down seem non excistant any thoughts? Does this new ECU need to learn my habits? any thoughts before I call them tomorow.

johnng117

This is the route i went and after changing the ECU it lasted 2 weeks before TB problem returned, i hope its fine for you as i know its a Pain in the ***.
The only thing that solved my problem is the Engine Wire Harness, as soon as it was changed signals to the TB was normal and all errors just disappeared even the ESP ones, been running really good lately, fingers crossed been a few month now.

johnng117

My shifts were not stable before i finally got it fixed too.
shifts were lazy and it was not too smooth either.


quote=Solarman2005;5078417]Well team got my car back from my repair man. What a run around!!! First of all bought a fellow forum members used TB and gas pedal assy, install and test no luck!!!!
limp the car to MB dealer scan check now they say need TB $2200 plus tax.
F that TB is good I am told.
Limp the car home wait till the next morning and drive the car to Toronto for my garage Euromotion to repair.
Next day he calls me and says he has trouble shot the car and I need a ECU ( no voltage to TB)
He gets a used ECU from C240 and replace board level components and retries.........
no luck need ECU from C32
2 weeks later I get ECU from 02 SLK32 used from a bone yard he gets ECU reprogramned and installed and turn key and the bictch runs. He test it for awaile and performs a road test and warm restart.
I go to Pick up car 6 hours labour scan and enviro fees and ECU program with 13%tax $900
I pay and drive car home and feels good. Only problem is off the line the shift point are slow and the kick down seem non excistant any thoughts? Does this new ECU need to learn my habits? any thoughts before I call them tomorow.[/quote]