I have a 01 5.3 and 03 pedal and tac module. The motor will fire up and idle fine without the module and pedal hooked up, but with them hooked up it wont start the fuel pump relay clicks rapidly when you turn the key on. also the scanner wont communicate. with the module unhooked i was able to get these codes
You can NOT run a 2003 throttle body and TAC on a 2001 PCM.
Trust me, I tried it.
When I got my C3 the stock 2001 DBW throttle body was damaged and it was impossible to find a 2001 DBW throttle body. (now of course they are all over ebay, and cheap!). I put a 2003 Throttle body and TAC in my truck and ran it that way for a while. Everything worked great unless you pressed the pedal to 80% or more. It would immediately trigger reduced power mode (engine running or not), and the ignition would have to be turned off for about 2 minutes to reset it. The 2001 PCM and 2003 TAC are incompatible, they will not communicate correctly.
I solved the problem by repinning my harness and running a 2003 PCM as well. Works great, but I do get BCM codes when I put on my scanner. Also I never got the PCM to correctly activate the AC clutch. I figured I would wire it straight to the switch if summer came and I hadn't figured it out, but now I am going a different route.
Today I am switching everything back over to 2001 PCM, TAC and pinning the harness back the way it was. I am putting on a TBSS intake and 90mm throttle body which will work with the 2001 TAC without an adapter module.
Side note, my 2001 accel pedal works successfully with both 2001 and 2003 TAC/PCM.
My motor, pedal and module all came from same vehicle to my knowledge. I do know for sure that my motor,ecu came from 2002 tahoe. Salvage yard sent me later on a DBW module and pedal. My module is all plastic and my pedal is all metal except APP SENSOR is obviously plastic. With TAC MODULE connected engine will not start, data port(aldl) goes out and fuel pump relay clicks rapidly. At this point I have verified that TAC module is getting 12v , all wires are correct and not broken or melted together. APP sensor is functioning properly in their suggested ranges. If I apply pedal down nothing happens at the throttle body. If TAC module is unplugged then engine cranks, runs and then idles up because TAC MODULE is unplugged. Any suggestions would be greatly appreciated. Sorry for hi jacking someone else's thread but I am hoping someone can help and if someone else read this maybe it will save them the trouble that I have been dealing with. Thanks