spot_55

OK guys I'm stumped... I have modified several harnesses for standalone operation and they all work flawlessly but this one. It's an 05 5.3 dbw . This is the first one I have had the GBCM wiring in it. All wires between the tac module and throttle body are good and I have 12 volts to the pink wire to the tac module. I have changed out the pedal, short harness, and the pedal from a running driving swap and it made no difference it would only idle. Does this GBCM have anything to do with this by chance? I threw in a harness from one of my other swaps and it runs great.This is the 5th DBW harness I have built and the only one with an issue.

ls1nova71

iTrader: (4)

How did you get around using the GBCM? The easy and common way is to wire it like the earlier trucks and then program it with an '03-'04 OS. If you did this, you also need a '03-'04 TAC and pedal. Just a thought.

spot_55

I didn't wire around GBCM and was using the factory 05 o.s. , tac module, pedal, and short harness. I thought this GBCM was just for alternator function... Will this keep an engine from revving ? I even put in the pcm from an 04 without the GBCM and it still had no throttle . Put in an 04 harness and used the 05 pcm and it works great. That's why I'm stumped is there something with the GBCM that is not allowing the pedal to operate?

ls1nova71

iTrader: (4)

Theres absolutely nothing in the GBCM wires that will keep the throttle from working. If it works with a different harness, then your problem is in the harness somewhere. Maybe a broken wire or a missed power wire, its hard to say without checking it.

spot_55

OK I figured out my issue while taking wires out of the c2 block the ground wire for the tac module was terminated in there. I have not came across the ground being in the c2 block before.added a ground and bench testing the harness and now have full pedal movement.

ls1nova71

iTrader: (4)

Glad you got it figured out!