1972moustacheride

Hi guys I have another tech question. I have recently fired up my 72 gmc with a 2004 ls engine in it. The red light came on so plugged my scanner into the obd2 port and got nothing to the scanner. So I tested the scanner on another vehicle and it came right on. I have checked all my grounds and everything looks good. I also have 12v coming out of the port. I also don't have any throttle response. I noticed that my tac module has a huge crack in it. I'm hoping a new tac module helps with throttle response. I'm stumped on it. This is my first time putting an ls into anything. Any help would be great. I want to drive this thing

ls1nova71

iTrader: (4)

Just posted on your other thread, but does the throttle body do the self check when you turn on the key? It should open a bit and close real fast, you'll hear it click.

1972moustacheride

It initially did at first then stopped. I will check to see if I'm getting power out of the tac module

33willys

iTrader: (1)

I think the first thing to do is to correct the problem with the ALDL then replace the TAC. If you have an '05 tune (popular) then there is a chance your TAC and pedal are mismatch to that tune. I recommend TAC #12588923 and pedal 15821777 if you have an '05 tune.

1972moustacheride

Where would I start to fix aldl port? I have 12v coming out of the aldl port. But scan tool still won't turn on. I tried to contact the guy that did my harness a few times this week and have had no luck.

1972moustacheride

Installed new tac module and it did fix a thing

33willys

iTrader: (1)

Really don't understand your last post, "did fix a thing". Do you mean it DIDN'T fix a thing? What TAC? What APP do you have? On the ALDL you should have three wires, 12volts, ground and data. I think they are A, B, and M. You may want to do your own research on the wire positions in the ALDL.

1972moustacheride

Oops sorry. It didn't help at all putting in the new tac module. I'm gonna see if I can find a schematic on aldl port

1972moustacheride

Ok after doing some trouble shooting I ended up having a ground issue. With ground problem fixed. The aldl is working. Scan tool pulls up as lost commutation a tac module. I have checked all the connections and the are good. I did replace the tac module. I was told when you replace it you have to disconnect battery for 30-45 minutes then connect it back and run the throttle pedal down 3 times to re set it. Is this true?

1972moustacheride

Update. After getting the aldl port to work. I ended up having a bad tv so I relaxed it. I started it up and it threw codes which pulled up to be lost communication at tac. With the codes cleared I have throttle response. As soon as I start it codes throw again and I have no throttle response. Is it possible I need to have my PCM flashed ?

ls1nova71

iTrader: (4)

So I'm going to guess that you get one press of the throttle and then it goes dead? Sounds like you definitely have a compatibility problem. If the PCM, TAC and pedal all came out of the same truck, then your tuner must have put the wrong year of tune in it.