Hello guys, need some help with my recently acquired '93 500E.
Car frequently goes into Limp-Home Mode. Most frequent LHM occurrence is right after starting the car up, and immediately moving the gear lever to Reverse. The car surges back wildly, I can feel the gas pedal moving by itself, and then the ASR light goes on and car immediately goes into LHM.
At times however, the car lets me pull away without problems and then goes into LHM in the middle of a drive.
Both the upper wiring harness and the ETA were replaced by previous owners. The ETA has build date 05/05.
I pulled the following codes with my analogue reader:
Pin 6 DTC 30 (CAN data bus to EA/CC/ISC interrupted)
Pin 7 DTC 3 (many options) and 14 (closed throttle position switch)
I then took the car to my acquaintance at official MB dealership, who was able to pull the following sub-codes on the Pin 7 DTC 3: #048 and #049, i.e. reference potentiometer and actual value potentiometer. Based on this, he claimed my ETA is faulty.
I'm obviously having a hard time accepting the fact that I need a new ETA, since I believed that buying a car with replaced ETA will save me the trouble and expense.
So my question to you: are the 048/049 codes a definitive proof that my ETA is dead? Given the strange symptoms (surging on reverse), could it be something else? Closed-throttle switch, neutral safety switch/safety contact switch?