I installed new heads intake and nick williams 102. Now I have the dreaded rep mode the only code that is showing up is p1518 I have done all the research went threw the test plan for p1518 on gear chatter the problem is when I cycle the key on I am getting 12v on the tac1&2 yellow and brown wire for a second then it gos to 1.6v at wot im getting 10-12v I have traced the tac wires found nothing just looking for some advice? and also what converts the 12v into the 5v? Tcm or PCM?

 

Anybody???

 

Is it a new Nick Williams T-body? Have you ever had the code before? Do you get the code with the key on engine off? What if you plug in another T-body, so you still get the code?

 

Yes the tb is new I have installed a truck 87mm no code but still have 12v spike when the key is turned on yes I get the code with the key on engine off I can clear the code and start and runs fine till I turn the key off and on again

 

I also have tried to the nw on my buddy's truck and it's fine also forgot to say I have cleaned and checked all the grounds and got a new battery and checked the pink wire going into the tcm it's good anything else I'm missing that will be giveing me 12v in a 5v circuit

 

I think you need a new mechanic

 

Had same problem on my 03 Burb a few years ago, replaced almost everything and problems still remained. What finally fixed it was replacing the tb connector with this one 88986255 CHEVROLET 8 WAY WIRE CONNECTOR PT1572 | eBay

 

Ok thanks I will look into this plug but t still think my problem in it the PCM or TCM

 

Ok I think I have a bad x link. With x link plugged in I'm getting 10v at key on and at wot. Unplug the x link everything normal and no p1518. Can drx chime in and give me some reasoning on this. X link is new. Bought couple of months ago.

 

More than likely he will chime in here. But I had problems and assumed the X-link was bad, it ended up functioning properly, and it was my truck. I will try and give info meanwhile. Did you cut the pink wires or leave them? I would first call Nick Williams and ask them if the throttle body is a replacement for the ls2 style, or the ls3/ls7 style.