Tac module and obdII HELP
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Tac module and obdII HELP 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
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.
Last edited by ls1nova71; Feb 9, 2016 at 07:45 AM.
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.
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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.
ALDL connection 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.
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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?
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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 ?
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.