Need help with a VW electronic throttle problem

[master_shake_]

i have an 05 beetle at the shop and im beating my head in trying to figure out the issue.

what i have is a p0121 code throttle pedal position #1 signal implausible.

data shown on my scan tool says throttle pedal position 1 90 percent throttle pedal position sensor 2 7 percent.

what i have done, i have measured each pedals voltage at the pedal they are both ~.5-.7 volts. at rest and full down they are 3ish volts at full matted pedal.

i have check the wires from the pcm to the pedal all 6 check out fine with an average resistance of .01-.03 ohms.

i have checked each 5 volt circuit and i get about 5 volts at each 5v in.

i have checked grounds at the pedal from the ecm to the pedal and each are again less than 1 ohm.

each sginal wire at the ecm reads the same as at the pedal.

i even adapted the throttle body for shits and giggles.

i'm certain it's the ecm thats bad, but i want to get some suggestions before i order it.

 

[DaTT]

Throttle position sensor?

 

[master_shake_]

Throttle position sensor?

the odd thing is the reading won't change on the scan tool for the throttle pedal even though the voltage does change on a volt meter.

 

[LTC8K6]

data shown on my scan tool says throttle pedal position 1 90 percent throttle pedal position sensor 2 7 percent.

Isn't that a bad TPS? The redundant sensors disagree?

 

[master_shake_]

Isn't that a bad TPS? The redundant sensors disagree?

when i disconnect the pedal tp 1 stays at 90 percent tp sensor 2 goes to 0.

 

[Mark R]

Is the ECM connector OK - sometimes the pins can corrode or push out. You measure teh correct voltage on the harness connector, but the pin isn't making contact with the ECM terminal.

Worth inspecting the connectors carefully and giving it a clean with some contact cleaner.

 

[master_shake_]

Is the ECM connector OK - sometimes the pins can corrode or push out. You measure teh correct voltage on the harness connector, but the pin isn't making contact with the ECM terminal.

Worth inspecting the connectors carefully and giving it a clean with some contact cleaner.

thought that too

took out the ecm gave it a once over with some contact cleaner.

ordered a throttle pedal as a known good, we'll see how that goes.

 

[master_shake_]

well got the new pedal same readings on my scan tool...

ecm is pooched off to the dealer it goes.

1000 for an ecm.

 

[Mark R]

Is the ECM fixable? Broken solder joint or something which someone could just hit with a soldering iron?

Bad capacitor or something?

 

[master_shake_]

Is the ECM fixable? Broken solder joint or something which someone could just hit with a soldering iron?

Bad capacitor or something?

not sure.

guess i could have pulled it apart i already had the ecm in my hand.