Hey all,

A few weeks back, went into limp mode (2001 TT with PO aftermarket tune and mods). Through this forum and other's the TPS error codes seemed straightforward. New TPS sensor, check. Happened again (although not as quickly/frequently) - changed out the throttle thinking something mechanical was the source. New throttle body, check! Just to be sure electrical power wasnt the issue replaced the battery, alternator, and voltage regulator.

Just went into limp again with the same TPS error code. Only thing left in the food chain as near as I can tell is the wiring harness and the ecu, any thoughts or tips on diagnosing before I go down the electronics rat hole with an otherwise well regarded but independent shop? I'm $5K deep in a recurring problem that should be routine.

Thanks in advance for the results/



Thanks for your advice.

 

That should be thanks in advance for the advice... fat fingers and spell check.

All advice welcome.

K

 

What are the codes?

 

p2135 Porsche Fault code 256 - accelerator pedal potentiometer
p0121 Porsche Fault code 427 - accelerator peral potentiometer. 1

Sitting in my garage I can get actual sensor readings. The pedal pot #1 reads .72V and 4.27V on #2 sensor, but when I look at the readings by % in the sensor opptions they track pretty similarly starting at 4% and going to 100% although there is usally a .5-1.5% difference.... one also seems to lag the other slightly.

I've taken the battery terminal off and gone through the rest options. Havent put it back on the road but presume the reason for the faults remain.

Thanks for the advice!

K

 

replace gas pedal.

 

Interesting suggestion, I didn't put in the new TPS myself, is there more than one linkage point? Trying to figure out how the new pedal might fix it (it's a lot cheaper/easier than a new wiring harness etc,).

K