UPDATE ON '02 ML320 PLEASE HELP!

[MercedesGirl37]

I took the SUV to a independant auto repair center. They only had a "generic" key to use the diagnostic tool, but it did read a CODE P0123, THROTTLE/PEDAL POSITION SENSOR
ID $10 ENGINE CONTROLLER
SWITCH "A" CIRCUIT HIGH"

Does any of this info tell any of you what this problem is? Since the repair shop does not really service Mercedes(He didn't even charge me for the test, which I though was very kind since most places want to rip people off or be dishonest.

Any advice from you experts..lol

[ArmyRover]

I don't know the code but sounds like a throttle position sensor.

edit: Did a quick search and turned this up on code P0123

Technical DescriptionThrottle Position Sensor/Switch A Circuit High Input

What does that mean?A P0123 code means that the the car's computer has detected that the TPS (throttle position sensor) is reporting too high a voltage.


SymptomsSymptoms may include:
Rough idle
High idle
Surging
other symptoms may also be present
CausesA code P0123 may mean that one or more of the following has happened:

TPS not mounted securely
TPS circuit short to ground or another wire
Faulty TPS
Damaged computer (PCM)
Possible SolutionsIf there are no symptoms, the simplest thing to do is to reset the code and see if it comes back.

If there are symptoms such as the engine is stumbling or hesitating, carefully inspect all wiring and connectors that lead to the TPS. More than likely the problem is with the TPS wiring. Check the voltage at the TPS (refer to a service manual for your vehicle for this specific information). If the voltage spikes or is too high (over 4.65 volts with key on, engine off), then that is indicative of a problem. Carefully trace each wire from the TPS wiring harness to check for breaks, rubbing against other components, etc.