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Shadow
01-23-2012, 07:57 AM
Accelerator Pedal Position Sensor (APPS)

While stopped, my accelerator pedal stopped working - the truck would only idle, depressing the pedal did not cause an increase in RPM.

I got off the road with the truck idleing, shut it off for 30 seconds, on restart the accelerator pedal was working again.

I had no CEL but the following codes were stored:

U1016 - ECM serial data communication lost

P2139 - APPS 2 and 3 out of range of each other

P2140 - APPS 1 and 3 out of range of each other

The APPS looked good back in the garage
KOEO pedal not depressed
1 0.686
2 4.392
3 4.000

I'm thinking that maybe the U1016 (ECM lost comm with another module) triggered the APPS DTCs.

Futher checks on the APPS look good.

0% Pedal idle and KOEO - within spec
1 0.686
2 4.392
3 4.000

100% Pedal KOEO - within spec
1 2.471
2 2.608
3 2.863

I cleared the codes and wiggled the APPS conection at the pedal and the 3 connectors at the ECM trying to get the codes to pop back up - they didn't.

From here the P2139 GM Diagnostic says the problem is intermittent.

Anybody have any thoughts on the U1016 causing the APPS DTCs - or maybe the U1016 was set at a different time than the P2139-P2140.

Thanks in advance for any input.

I edited my signature and don't know why it's not appearing - '05 YF5 2500 LLY/Allison 2WD Stock