2007 6.0 LS Swap Corvette - P2138 DBW - no throttle response.

[BML72Nova]

I have been stuck on this one for a while now and can't seem to make sense of it at all. Have been reading up on multiple threads with no avail and thought I would take a shot here.

engine runs but cannot get out of 'limp' mode - no throttle response for my DBW. only code showing is P2138.
Confirmed the wiring is correct (read multiple places where wiring may need to switch on one circuit.
6.0 2007 Corvette - e38 ECM(Original) -Original Throttle Body, Stock replacement Pedal

Both ECM flashed/VATS removed and Harness rewired professionally by Current Performance. (TUNE ATTACHED)

Idle = No pressure on pedal, Full = Fully Pressed

Accelerator Position D (SAE), Idle 17.3%, Full 78.4%
Accelerator Position E (SAE), Idle 83.5%, Full 91.4%
Accelerator Pedal Position, Idle 0.0%, Full 99.0%
Accelerator Pedal Position 1, Idle 0.0%, Full 99.0%
Accelerator Pedal Position 2, Idle 99.0%, Full 99.0%
Accelerator Pedal Position Sensor 1, Idle 0.86 V, Full 3.90 V
Accelerator Pedal Position Sensor 2, Idle 4.16 V, Full 4.55 V
Accelerator Pedal Mode, Idle Limited, Full Limited
Throttle Position (SAE), Idle 27.10%, Full 27.10%
Relative Throttle Position (SAE), Idle 15.30%, Full 15.30%
Commanded Throttle Actuator (SAE), Idle 16.10%, Full 16.10%

[blindsquirrel]

Log file would be a help, logs show the two ETC segment IDs that aren't in the tune file. (and don't use the generic SAE channels for GM ETC stuff)

You should use the Express van 4L80E TCM (24239927) with this, not the Suburban (24235341).

Have you looked at published diagnostics for P2138? I think it's interesting that the only condition that'll set P2138 is high resistance in ANY of the circuits, and no other conditions will set P2138.

Attachment 114443

[blindsquirrel]

The APP sensor 1 signal voltage at rest position is less than 1 volt and increases to above 4 volts as the pedal is actuated. The APP sensor 2 signal voltage at rest position is near 0.5 volt and increases to more than 2 volts as the pedal is actuated.

Your numbers do not match that description.

[BML72Nova]

Thank you for your reply, I am attaching logs, not sure if I pulled correctly as it is my first time pulling them.
Best I can tell in all my testing has been this is what is causing it - Accelerator Position E (SAE) 83.9 %

I will look into the TCM - looks like a whole other can of worms but the part # on the TCM from CurrentPerformance is 24252114

6.0 LS Swap.hpl

[2xLS1]

Your position E sweep looks odd compared to position D and that code is position d/e correlation.

[BML72Nova]

Your numbers do not match that description.

Agree- APP sensor 2 showing > 4 Volts. I swapped the pedal with a new one and got the same result.

[cadillactech]

I would verify the wiring is correct. Your APP 2 should sweep from .5V to over 2V at full pedal.

[BML72Nova]

I would verify the wiring is correct. Your APP 2 should sweep from .5V to over 2V at full pedal.

I will definitely run through them all again. Have compared to multiple wiring diagrams and all seem to be wired correctly.

[blindsquirrel]

Attachment 114446

[BML72Nova]

Attachment 114446

Thank you, Saved me some time. I am not sure why but cannot insert the picture, confirmed though this is the same wiring.

[blindsquirrel]

I would check it with the APP unplugged and key on - make sure the 5vrefs have ~5v, the grounds are ground, and the signal returns have 0 volts (ECM has pulldown resistors on the signal lines so they should be 0v and not some random float voltage). If you have anything other than 0v on the signals you have a harness issue (short to voltage). Or very unlikely, an ECM internal issue.

[blindsquirrel]

Attachment 114448

[blindsquirrel]

Just checked your logfile, the two hidden ETC segments are correct (and unmodified) for that VIN and the rest of the IDs.

[BML72Nova]

I would check it with the APP unplugged and key on - make sure the 5vrefs have ~5v, the grounds are ground, and the signal returns have 0 volts (ECM has pulldown resistors on the signal lines so they should be 0v and not some random float voltage). If you have anything other than 0v on the signals you have a harness issue (short to voltage). Or very unlikely, an ECM internal issue.

I am about to go out now so can't validate for a few hours but I think you may have solved my problem... Disconnected everything - APP sensor 2 Signal is showing 5V disconnected...Traced it back to the ECM - Clean wiring all the way back - Goes to PIN 32 (Circuit 1162) as it should... Still 5V - Took the Connector off the ECM and what do you know - PIN 16 is bent and touching Pin 32!!! going to try and move that out later...will keep you posted. If I could figure out how to attach a picture I'll upload too.

[BML72Nova]

I am about to go out now so can't validate for a few hours but I think you may have solved my problem... Disconnected everything - APP sensor 2 Signal is showing 5V disconnected...Traced it back to the ECM - Clean wiring all the way back - Goes to PIN 32 (Circuit 1162) as it should... Still 5V - Took the Connector off the ECM and what do you know - PIN 16 is bent and touching Pin 32!!! going to try and move that out later...will keep you posted. If I could figure out how to attach a picture I'll upload too.

UPDATE! This is exciting for me. Hooked all wiring back up and no more trouble codes! All values look good, even the throttle body opens and closes now. Engine is completely out so need to do some work to safely bench test a start but I think its fixed!
Bent the PIN 16 back to where it should be (was perfectly lined up to go into 32 and looked normal unless inspecting with magnifier, I have been looking at these PINS for 6 months and never noticed)

[slwryde]

I would check it with the APP unplugged and key on - make sure the 5vrefs have ~5v, the grounds are ground, and the signal returns have 0 volts (ECM has pulldown resistors on the signal lines so they should be 0v and not some random float voltage). If you have anything other than 0v on the signals you have a harness issue (short to voltage). Or very unlikely, an ECM internal issue.

I know this is an old thread but I am desperate. I'll offer some specs on my LS swap project.

2005 Corvette LS2
DBW throttle body (original to engine)
T56 Magnum
Purchased a 2005-2013 corvette gas pedal through summit.
Wiring Specialties DBW harness
E40 programmed with vats deleted

The engine starts but no throttle response. Two codes P2138 and P060D.

I did unplug the accelerator pedal. Everything checks out except APP2 voltage fluctuates 3.6 ,,, 3.8 ,,,3.5,,,3.6
Im starting to think the computer may be bad.

Any advice is appreciated.

[edcmat-l1]

I know this is an old thread but I am desperate. I'll offer some specs on my LS swap project.

2005 Corvette LS2
DBW throttle body (original to engine)
T56 Magnum
Purchased a 2005-2013 corvette gas pedal through summit.
Wiring Specialties DBW harness
E40 programmed with vats deleted

The engine starts but no throttle response. Two codes P2138 and P060D.

I did unplug the accelerator pedal. Everything checks out except APP2 voltage fluctuates 3.6 ,,, 3.8 ,,,3.5,,,3.6
Im starting to think the computer may be bad.

Any advice is appreciated.

Bump a years old thread. No data log, no tune file, barely any real info. Good luck to you sir.

[slwryde]

Sorry guys, I figured it was a long shot. Thanks for the well wishes.

1. I knew it was an old thread and did mention that.
2. I have no data log or tune file. I had a guy out in Arizona get me a corvette VIN and Flash the computer.
3. Barely any real info. I guess not.

From what I read from the info "blindsquirrel" posted I figured I might have a bad ECM. Any way I'm not looking for arguments and I apologize.