BBV solenoid wiring - L67 swappers please help

**WillOverkill** · 04-09-2008

I have a customer that put an L67 in his 99 GT. While doing some tuning for him on Monday, I provided him with a wiring harness I fabbed up to connect up his boost bypass valve solenoid, which is required for some of the controls in my newest PCM tunes. It didn't work, and he's stuck at 4psi. He does have a proper L67 tune.

I ran the grey wire to pin 77 in the PCM, but the other wire I connected to ground and am wondering if it should have been connected to a 12volt source?

I don't have any GM wiring diagrams and Alldata doesn't show me the BBV connector view.

Any help is greatly appreciated!

**fst** · 04-09-2008

Will, have u tried contacting anyone over hp tuners or dhp forums?

**Sabrewings** · 04-10-2008

This help? I assumed a 1999 L67 was used and brought up the connector information for a 1999 GTP. I'm not sure if there were any year differences without going through year by year.

Looks like the other wire was supposed to be a 12V source. PCM probably provides the ground.

Edit: Found this. Looks like we were right that the 12V source is applied through the connector from the fuse box, and the PCM pin 77 provides the ground.

**WillOverkill** · 04-10-2008

Excellent, thank you very much!

**Reptile** · 04-10-2008

Might have to use a 99 GTP PCM.....DeanGTP had this issue, and it turned out he had a GT PCM with the improper OS. Put in a known GTP PCM and the problem was fixed.

TDCRacing · 04-10-2008

Originally Posted by Reptile

Might have to use a 99 GTP PCM.....DeanGTP had this issue, and it turned out he had a GT PCM with the improper OS. Put in a known GTP PCM and the problem was fixed.

I knew this thread sounded fimiliar when he said he was stuck at 4 psi...glad you were able to remember