khangee

Hi I'm in need for some help here. Last week after work the car started fine but there was no response to gas pedal. ESC error and check engine light on.Tow the car the shop. scanner showed P0120 code and the mechanic said it was TPS sensor problem. Replaced TPS no luck then throttle body is replaced (both part are new) but the car still have the same problem. Still no response to gas pedal and RPM fluctuate at 10000 and 15000. One thing I noticed after clearing code and starting car there is no CEL but as soon I press gas pedal the CEL comes on. Please help

Plutoe

What is your definition new??---new to the car. a new junk yard, a new used car a new guy on the street cornor---my point is----- did the sensor come from a MB dealer!

khangee

Yes the TPS is from dealer and the throttle body NEW from online, both are same part numbers as original and on both I spend $740 + labor shop will charge. Still have same problem.

HappyWagon

Clear any current code(s), then drive a bit to see if code(s) returns.

Ooops...forgot you'd done that already.
Sorry

HappyWagon

Try cleaning the MAF.

Do you get the same error code?

Plutoe

First, please do not waste your time with doing any thing related to the MAF---P0120 relates to a faulty potentiometer(there are 4) within the throttle valve actuator(M16\6)---spend your time on the fault, not on creating more!!

If your buddy mechanic suggested that the pedal value sensor(B37) was at fault he does not understand the cars throttle system and wasted your money---this has nothing to do with your throttle actuator fault. Have him put yours back on and return your money!!

The throttle valve that you purchased on E-bay thinking it was new, I think is HS--you purchased a faulty valve. Return it, throw it in the river, but you need a good one, or simply park or sell the car!!

Another butcher mechanic that thinks he knows MB systems---what a pitty!!!

HappyWagon

Check for broken throttle cable.

Maybe resetting the transmission adaptations, which also involves resetting the throttle stops, may help.

Also ensure the wires/harness at the TPS are fully intact.

khangee

Thanks guys for your response. I did not buy throttle body from ebay but from pelican parts dot com it was in original bosch package and was brand new. yes its the same code every time P0120. He check the cable from gas pedal and clean most of the stuff with CLR spray. Could it be the ECU? How do I reset transission adaptations and throttle stops? I can't find a thread here on this site how its done. Thanks in advance.

HappyWagon

(Found the following at -- http://www.benzworld.org/forums/r170...arameters.html)

1. Get in your car, it doesn't matter if you close the door or not.

2. Turn the key to the on (not start) position, the position just before the starter turns over.

3. Press [and hold] the gas pedal to the floor with the key in the "on" position.

4. Hold the pedal to the floor for five seconds, then turn the key back
to the "off" position (don't remove the key), then release the gas
pedal.

5. Wait 2 mins. [for the reset to occur].

6. Drive the car as you always do[...OR...First, ensure the engine is warmed up (min. 80°C). Find a stretch of road, if you want to manually shift through the gears (40 shifts should do it) keeping RPMs somewhere between 1500 and 2000, depending on your driving style.]