Help with DBW / TAC function
Thread Starter
Teching In
Joined: Jan 2023
Posts: 49
Likes: 5
From: St. Louis
Help with DBW / TAC function I'm getting fuel, Spark, ignition, but it won't run because the throttle body has zero movement.
Engine fires up for 1 second until ths TB gets sucked shut.
My problem is zero TB response.
94 Caprice
Swapping in a 04 Yukon LQ4 6.0
I'm running the stock 04 Yukon
Throttle Body
TAC module
PCM (vats tuned out)
MAF
Also running
Truck pedal sensor (bought another and the voltages match so I'm fairly certain it's correct)
Ebay extended vette tac to pedal wire (I crosswired E to J to match truck wiring)
Ebay intake tube
Ebay swap harness (everything pretty nice, confirmed others install and function before purchase)
2 block ground straps
1 battery Ground strap
1 harness ground strap
So I have voltage at the pedal.
ive tested the TB wires,
I've also tested the TB and it flips and flaps with 12v to yellow and brown.
my tuner says nothing on his end should affect the DBW.
NO CODES ARE THROWN
How do i go about testing the TAC module and wiring harness to eliminate these possibilities?
I'm at the end of 3 days of searchable videos and threads about this
Thanks for any help
Engine fires up for 1 second until ths TB gets sucked shut.
My problem is zero TB response.
94 Caprice
Swapping in a 04 Yukon LQ4 6.0
I'm running the stock 04 Yukon
Throttle Body
TAC module
PCM (vats tuned out)
MAF
Also running
Truck pedal sensor (bought another and the voltages match so I'm fairly certain it's correct)
Ebay extended vette tac to pedal wire (I crosswired E to J to match truck wiring)
Ebay intake tube
Ebay swap harness (everything pretty nice, confirmed others install and function before purchase)
2 block ground straps
1 battery Ground strap
1 harness ground strap
So I have voltage at the pedal.
ive tested the TB wires,
I've also tested the TB and it flips and flaps with 12v to yellow and brown.
my tuner says nothing on his end should affect the DBW.
NO CODES ARE THROWN
How do i go about testing the TAC module and wiring harness to eliminate these possibilities?
I'm at the end of 3 days of searchable videos and threads about this
Thanks for any help
Last edited by Alpha_numeric44; May 1, 2024 at 07:40 PM.
TECH Enthusiast
Joined: Jul 2019
Posts: 636
Likes: 187
I'm getting fuel, Spark, ignition, but it won't run because the throttle body has zero movement.
Engine fires up for 1 second until ths TB gets sucked shut.
My problem is zero TB response.
94 Caprice
Swapping in a 04 Yukon LQ4 6.0
I'm running the stock 04 Yukon
Throttle Body
TAC module
PCM (vats tuned out)
MAF
Also running
Truck pedal sensor (bought another and the voltages match so I'm fairly certain it's correct)
Ebay extended vette tac to pedal wire (I crosswired E to J to match truck wiring)
Ebay intake tube
Ebay swap harness (everything pretty nice, confirmed others install and function before purchase)
2 block ground straps
1 battery Ground strap
1 harness ground strap
So I have voltage at the pedal.
ive tested the TB wires,
I've also tested the TB and it flips and flaps with 12v to yellow and brown.
my tuner says nothing on his end should affect the DBW.
NO CODES ARE THROWN
How do i go about testing the TAC module and wiring harness to eliminate these possibilities?
I'm at the end of 3 days of searchable videos and threads about this
Thanks for any help
Engine fires up for 1 second until ths TB gets sucked shut.
My problem is zero TB response.
94 Caprice
Swapping in a 04 Yukon LQ4 6.0
I'm running the stock 04 Yukon
Throttle Body
TAC module
PCM (vats tuned out)
MAF
Also running
Truck pedal sensor (bought another and the voltages match so I'm fairly certain it's correct)
Ebay extended vette tac to pedal wire (I crosswired E to J to match truck wiring)
Ebay intake tube
Ebay swap harness (everything pretty nice, confirmed others install and function before purchase)
2 block ground straps
1 battery Ground strap
1 harness ground strap
So I have voltage at the pedal.
ive tested the TB wires,
I've also tested the TB and it flips and flaps with 12v to yellow and brown.
my tuner says nothing on his end should affect the DBW.
NO CODES ARE THROWN
How do i go about testing the TAC module and wiring harness to eliminate these possibilities?
I'm at the end of 3 days of searchable videos and threads about this
Thanks for any help
"Ebay extended vette tac to pedal wire (I crosswired E to J to match truck wiring)"
i am not sure what that is but it sounds sketchy. Its the only thing that isnt stock in your configuration.
you shouldn't even have to start the engine, you should be able to turn ignition on, then press the pedal and see throttle body movement. if that doesn't work, you have an issue. time to pull out a scanner and start looking at data for the gas pedal sensors and the throttle position sensors.
