No throttle Dbw (pulling my hair out)

[1978chev]

Ok guys I need some help I have a 69 c10 I installed a motor out of an 02 Tahoe
Dbw got a new harness and Pcm flash from Bp auto put it all in and it fires and idles perfect but absolutely no throttle.
Got a p0122 code went through the diag procedure and got my 5 volt ref got good power and ground going to tac module (it's the all plastic module which should be the right one) but on my scanner it shows no voltage when I jump the 5volt to the signal wire , I've checked the wires at tac module and when jumped the signal wire has 5 volts but nothing on the scanner I'm thinking its a tac module but wondering if I'm overlooking anything.
Any help or advise would be appreciated
Thanks Darrell

[nsb29]

Originally Posted by 1978chev

Ok guys I need some help I have a 69 c10 I installed a motor out of an 02 Tahoe
Dbw got a new harness and Pcm flash from Bp auto put it all in and it fires and idles perfect but absolutely no throttle.
Got a p0122 code went through the diag procedure and got my 5 volt ref got good power and ground going to tac module (it's the all plastic module which should be the right one) but on my scanner it shows no voltage when I jump the 5volt to the signal wire , I've checked the wires at tac module and when jumped the signal wire has 5 volts but nothing on the scanner I'm thinking its a tac module but wondering if I'm overlooking anything.
Any help or advise would be appreciated
Thanks Darrell

if the pedal did not com w/the motor there it could be a deferens in the wiring my brother had to switch to wires to make his work I think his motor was the same as yours and his pedal came from a corvette

[BR3W CITY]

'vettes have a different input/output, so thats why he had to switch those. 02 was less common to get DBW on trucks, most didn't phase in until mid 03. Was the ECM from the same 02 tahoe? Where were the TAC and pedal from?

[1978chev]

The Ecm was supposedly from the same vehicle I bought complete engine with harness and ecm all together but what is weird now when I look at the vin through the scanner it comes out to an 02 2500hd with a 6.0 I don't know if bp re wrote the vin or what but they did flash it.
I bought the tac module with harness and pedal all together on line.
It did not tell me what vehicle it came from

[1978chev]

I have a few different pedals and have tried them with no difference
Just for your guys FYI trying not to let this thread die kind of desperate

[not2oldchevy]

tuned for cable. have a friend that had the same problem

[Big Port Jimmy 6]

I have a 02 5.3 DBW in my truck it is out of an Avalanche and the VIN in the tune is the Avalanche vin. Call the tuner and ask. Some of the early DBW PCMs will not be able to be tuned for cable, because the will not support the IAC Motor. Jay

[1978chev]

I will call Bp auto in the morning to verify but with my scanner I can adjust the idle through the iac up to about 800rpm then it will not go beyond that .
if I can get my hands on another tac module I will try that before spending the 400.00 on a new one I'm just not certain that is the problem and I hate just swapping parts but my diag sheet is saying pcm and I thought the tac module was a seperate unit not controlled by the pcm (I know they talk to each other but did not think the tac module was controlled by the pcm) thanks for the input guys

[ls1nova71]

I doubt its the TAC, sounds like the tune to me. Is it a 411 PCM?

[1978chev]

did not get a chance to call bp today but i forgot it throws a code p0122 for the app sensor a circuit

[not2oldchevy]

Have a friend that wound up with two of everything, it did not rev until he had it retuned. They had it tuned for cable by mistake.

[1978chev]

Called bill at bp today he said send him the pcm and he will verify if it was set up
For Dbw or not. And yes ls1 nova it is the 411 pcm

[1978chev]

Got my pcm back and it was not tuned for Dbw. Hopefully this may help someone else thanks for the help guys