LB7: P0207 and P1261 engine limp

[1chevy02]

I'm getting a P0207 Injector 7 control circuit
P1261 Injector posoitive control circuit group 1
On an 02 it has a miss and will go into engine limp. I checked the plug coming out of the valve covers and it looks fine. Any ideas? Which color wire is the positive control wire for injector #7?

 

[JoshH]

Check the wires coming out of the FICM. Make sure they aren't rubbing on the bracket where it turns and goes by the alternator. It's more common on LLYs, but a few guys have seen it on the LB7 too.

 

[Canadian Cowboy]

Red/black,here is the electrical manual go to page C19

2003 Beyond GM C K series truck Electricial Manual.pdf

CC

 

[1chevy02]

Check the wires coming out of the FICM. Make sure they aren't rubbing on the bracket where it turns and goes by the alternator. It's more common on LLYs, but a few guys have seen it on the LB7 too.

Can't seem to find any rubbed wires Could it be a faulty injector coil or loose nut on injector wire. Truck has recently had injectors put in.

 

[1chevy02]

Red/black,here is the electrical manual go to page C19

2003 Beyond GM C K series truck Electricial Manual.pdf

CC

Thank you:hug: I assume the 02 will be the same as the 03 listed in that manual?

 

[JoshH]

Might want to take a multimeter to the FICM and probe the wires for injector #7.

 

[Canadian Cowboy]

Thank you:hug: I assume the 02 will be the same as the 03 listed in that manual?

yes

 

[1chevy02]

No bare spots on any wires that I can find Could it be a bad injector? I guess I'm going to pull the valve covers and see if there is something wrong under there.

 

[JoshH]

Did you try probing the FICM harness?

 

[1chevy02]

Not yet going to try that tomorrow. I also have a spare ficm to try, just in case.

 

[1chevy02]

I have swapped FICM, ECM, engine wire harness, and still nothing. Will only set DTC with engine warm. Shut it off and restart and it runs fine for a little while. Balance rates all under 1. It almost has to be #7 injector. I guess I'm going to pull valve covers and swap in a known good injector and hope for the best.

 

[1chevy02]

Anyone ever have this code set by a bad injector?

 

[1chevy02]

update. It ended up being a bad harness under the valve covers.