you wanna make sure you have power at tac when key on, but not when key off... if you have power at key off that is bad

also check your cruise, brake , and any other related fuses because if the cruise fuse or any other related fuse is blown the tac will not respond....

 

Got you on the fuse thing. I also need to sheck for a Throt Cont fuse, I was told that fuse is a 15A. Do you have any idea which wire on the connector should be getting power? I do not have a wiring diagram oother then whats in the Haynes book and it does not cover the module at all. It has 2 connectors coming into it, it looks like the inboard one goes to the brake booster and the other one would be my concern.

Also would I be looking for 12V or 5V @ that wire.

 

heres you a few diagrams

 

THANK YOU VERY MUCH!!! I was having trouble with scanner and could not upload that.... i was damn close to getting your address to mail it to you..... the pink wire is the b+ voltage.... the pink wire should only have voltake with key on.... when key off it should not..... start there... is it always has power... it is shorted..... and theres your problem.... if not let me know and well take next step...

Thank you big bad wolf for pullin through for him

 

no problem you can thank GM for the diagram hahaha, I work at the dealer...but you might also want to check the yellow and the brown wire at the TB itself, I have seen a few of those break inside the insulation and cause weird problems...

 

haha.... which dealer?.... i work for GM...... taht why most of my posts are in caps because the damn gm system uses caps.....

the bitch part was i wanted to upload those but teh damn scanner in my office wouldnt work

 

not to hi-jack but......I work at Lake Country Chev - Cadillac in Muskogee,Ok I'm the everything but tranny,diesel, and rear-end guy<mostly driveability and elec> wonder if SS has this figured out yet as I would hate to see a 408 not being utilized properly haha

 

ive seen this problem a couple times where the ign + gets grounded to constant... and when that happens the tac will stay on full time. so when the pcm starts it sees the tac already on, when the tac is supposed to power up after the pcm. and all the pcm needs is 1 second of inaccurate info and it will go into reduced power

 

What would have happend to cause that?

 

inside the ignition switch could short..... wiring going to tac.... especially close to tac...... wires can also break like big bad wolf said