2009 Buick Lacrosse 3.8L with APP problem

[shay]

there is intermittent DTC hard to Duplicated - p2120 p1125 p2138
I changes:
1 Throttle body- new
2 Used APP
3 new connectors for the APP and Throttle body used.
4 restoration fot the 6 wiring from APP to Throttle body.
5. I check throttle body ground and power look good.

*Do you thinks I need to check the communication line between PCM to Throttle body for this DTC?
*Do you have any tip from your experience?


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[Crusty]

there is intermittent DTC hard to Duplicated - p2120 p1125 p2138
I changes:
1 Throttle body- new
2 Used APP
3 new connectors for the APP and Throttle body used.
4 restoration fot the 6 wiring from APP to Throttle body.
5. I check throttle body ground and power look good.

*Do you thinks I need to check the communication line between PCM to Throttle body for this DTC?
*Do you have any tip from your experience?


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If you download ShopStream Connect (SSC) from this site, you can save and replay movies of data, such as the TAC data group.
Record the data from the vehicle you're working on and here is a Known-Good vehicles recording. This one happens to be a 2009 model year GM but not the same model as yours.
I'm pretty sure most of the data pids will be the same.

Compare your saved movie to this one.
HTH

[maven]

These codes represent a problem with the accelerator pedal, its wiring or the ECM. The throttle body isn't the issue.

If I read what you've done properly then you have new connector at the pedal and a used pedal. I would recommend a new pedal as the most likely fix. This is a very common set of codes on the W bodies.

Ias for addition checks to make before you replace anymore parts...look at connector c101(20way Grey round) make sure the terminals are crimped tightly to their circuits add solder as necessary to be sure and lubricate the connection with dielectric compound before reconnecting.
Same goes for the terminals at the ecm. Check for tension, solder to wire and lube .

Last thing to do before replacing the pedal is to load test the circuits and take a voltage drop test of each wire. If all test OK, replace the pedal. If it comes back with a new pedal, soldered terminals and good wires then it'll need an ECM. I have never replaced an ECM for a P2138. I've replaced easily 60+ pedals in the last half dozen years

[Crusty]

These codes represent a problem with the accelerator pedal, its wiring or the ECM. The throttle body isn't the issue.

If I read what you've done properly then you have new connector at the pedal and a used pedal. I would recommend a new pedal as the most likely fix. This is a very common set of codes on the W bodies.

Ias for addition checks to make before you replace anymore parts...look at connector c101(20way Grey round) make sure the terminals are crimped tightly to their circuits add solder as necessary to be sure and lubricate the connection with dielectric compound before reconnecting.
Same goes for the terminals at the ecm. Check for tension, solder to wire and lube .

Last thing to do before replacing the pedal is to load test the circuits and take a voltage drop test of each wire. If all test OK, replace the pedal. If it comes back with a new pedal, soldered terminals and good wires then it'll need an ECM. I have never replaced an ECM for a P2138. I've replaced easily 60+ pedals in the last half dozen years

Agreed Maven
Shay needs to TEST, not TOSS.....

[shay]

Hi
Thanks for help.
In this car vin 2 the throttle body is the APP module.
I test with pico connected app sig 1 and app sig 2 while wiggling the Wiring Harnesses and during driving, no change in min or max volt.
The DTC set after 1 or 2 week.
My question is the communication line between PCM to Throttle body can set this DTC??

Thanks
shay

These codes represent a problem with the accelerator pedal, its wiring or the ECM. The throttle body isn't the issue.

If I read what you've done properly then you have new connector at the pedal and a used pedal. I would recommend a new pedal as the most likely fix. This is a very common set of codes on the W bodies.

Ias for addition checks to make before you replace anymore parts...look at connector c101(20way Grey round) make sure the terminals are crimped tightly to their circuits add solder as necessary to be sure and lubricate the connection with dielectric compound before reconnecting.
Same goes for the terminals at the ecm. Check for tension, solder to wire and lube .

Last thing to do before replacing the pedal is to load test the circuits and take a voltage drop test of each wire. If all test OK, replace the pedal. If it comes back with a new pedal, soldered terminals and good wires then it'll need an ECM. I have never replaced an ECM for a P2138. I've replaced easily 60+ pedals in the last half dozen years

[maven]

I have never seen this code set due to the ecm to tb communication wires.

Carefully inspect all 6 wires from pedla to TB for open,shorts,high resistance.
Open connector x101 and inspect for water intrusion. Scope the app1 and 2 outputs while applying throttle....apply sideways force to pedal as pressing down on pedal.
Like I mentioned before....closely pay attention to the pedal itself. While it can be the TB its unlikely in my experience at the dealer.