E38 DWB pedal not working

[lsrado]

I have a 4.8L and 4L80E from a 2008 express 2500 going into a 2007 colorado 2wd 4cylinder. I sent the stock harness out to be modified to run standalone (by standalone harness) and just fired it up for the first time today to check for oil pressure and to hear it run. It fire right up! but when I push on the gas pedal it does not rev up. Any ideas? The pedal is from the colorado, I checked the wiring of the 6 wires and I believe it is correct, the colors even matched up. In the VCM scanner the "Accelerator Position D (SAE)" changes from 19.2 at idle up to around 88 fully depressed, but nothing changes.

First start 2018.11.20.hpl

start 1.hpt


2008 4.8L
Elgin 1840P cam
Pac 1218 springs

[Jon S.]

It would seem that the nice people at Standalone Harness may not fully understand how the Gen 4 throttle controls function - or perhaps that you did not fully explain to them what you were doing.

The likely source of the “no throttle” issue, is that the E38 ECM calibration is not completely compatible with the Colorado APP (accelerator pedal).

You may either need an E67 ECM, programmed as an LH8 5.3L Colorado (which would mean converting your wiring harness from E38 connectors to E67 connectors), or you may need to use the APP from the 2008 Express van.

Electronically speaking, the 2008 Express and 2007 Colorado APPs are loosely similar - but not the same.

[lsrado]

I was afraid of that. I still want to make sure there wasn't something easy I was missing. The weird part to me is that in the log I show the accelerator position moving so I would think I am ok?

I have a friend with a spare 2011 camaro pedal, any chance it will work? If not I will have to hunt for a 08 express 2500 in the junk yard.

[Jon S.]

Electronically speaking, the Camaro pedal is not the same. The Camaro pedal also uses a different connector for the APP (it looks a little like your MAF connector).

The APP connector for your Colorado is the same as the 2008 Express - rectangular with a reddish sliding lock mechanism.

For diagnostic purposes, getting an APP from a 2008+ LSx engine Express van to try, would be the easiest way to determine if that indeed is your issue. You would not need to mount the Express APP in the Colorado - just plug it in and try it while holding the pedal in your hands.

[lsrado]

Any chance the pedal isn't working because I dont have the TCC or check engine light wired? Also I am not running a MAF (I wired in a 2 wire IAT from a 3800) or O2s yet as I plan on speed density only in the future with a turbo. I did not disable any SES lights yet.

[Jon S.]

Oh boy - that is quite a lot of things that are not connected - the only one that may be causing related issues is the missing MAF (unless the calibration has been configured for Speed Density operation - MAF setup to fail immediately).

Are you getting any (actual or pending) of the following DTCs ?

- P0120 to P0123
- P0220 to P0223
- P0606
- P060D
- P1516
- P2101
- P2120 to P2138

If so, these would point to an APP versus calibration mismatch.

[lsrado]

I do have P2138.

codes.JPG

[lsrado]

SOLVED!

i tried a 2009 silverado pedal and it worked but the pedal was too different to mount in the colorado. My friend gave me a 2010 camaro ss pedal and i wired it up and it also works and is a much easier fit in the colorado.