Accelerator Pedal Position Sensor - Cobalt

Status
Not open for further replies.
Joined
Feb 25, 2013
Messages
2,058
Location
NY
'06 Chevy Cobalt LT 111K throwing code P2138

P2138 Accelerator Pedal Position (APP) Sensor 1-2 Correlation -PCM

Lots of conflicting advice online.

I was going to try to locate and replace the APP sensor since it sounds simple enough (3 bolts and a connection near the gas pedal?). Is it this simple? Anything I should watch out for?
 
I believe that was the same code my Ion (Cobalt's sibling) threw .....it also showed the 'Reduced Power' light.
This happened after I had a key made that didn't work and attempted to put it in the ignition.

I solved the problem by disconnecting my battery for 24 hours....I think it cleared the PCM...
 
Originally Posted By: pbm
I believe that was the same code my Ion (Cobalt's sibling) threw .....it also showed the 'Reduced Power' light.
This happened after I had a key made that didn't work and attempted to put it in the ignition.

I solved the problem by disconnecting my battery for 24 hours....I think it cleared the PCM...


pbm - Was this thread the same issue you were thinking of or were referring to or did you have a separate problem?

'Reduced Engine Performance' on an Ecotec 2.2

I did also go into limp mode.
 
Sometimes the computer needs to go through a "relearn" procedure to get the throttle by wire to function correctly. Other times, cleaning the throttle body solves the problem.

If you are lucky, you can get the car to function correctly again without replacing any parts.

I don't know what an accelerator pedal sensor or a reman throttle body costs, but I know they aren't cheap.
 
Last edited:
My guess would be that there is a disagree between channels 1 and 2 of the APP sensor. It is a 2 channel sensor, for safety. If they ever disagree,the actual position reported cannot be trusted, so limp mode would be the best response. Check you connections for corrosion too.
 
Last edited:
Originally Posted By: 99Saturn
Originally Posted By: pbm
I believe that was the same code my Ion (Cobalt's sibling) threw .....it also showed the 'Reduced Power' light.
This happened after I had a key made that didn't work and attempted to put it in the ignition.

I solved the problem by disconnecting my battery for 24 hours....I think it cleared the PCM...


pbm - Was this thread the same issue you were thinking of or were referring to or did you have a separate problem?

'Reduced Engine Performance' on an Ecotec 2.2

I did also go into limp mode.



Yes....That's the problem I was referring to.....disconnecting the battery overnight solved my problem without changing any parts...
 
Quick update - swapped the sensor out over Memorial Day weekend, too soon to tell if the problem is solved since it was/is intermittent (only driven ~100 miles) but the swap was easy. 3 bolts and one connection. Awkward position to see the bolts but I didn't have to remove anything else.
 
Another update: Apparently no luck fixing the problem with the new pedal sensor (assuming the new pedal I got was not bad). A little over 400 miles from the original install, limp mode right as I was leaving work.

Pulled back into the parking lot, checked the code to confirm it was still the same (it was). Restarted the car and drove home (no issues for the trip)....
 
Status
Not open for further replies.
Back
Top