DBW wiring/voltage issues.
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TECH Fanatic
Joined: May 2010
Posts: 1,081
Likes: 8
From: Atlanta, Ga
DBW wiring/voltage issues. I am in the midst of swapping a Blue/Green PCM for an E40 in my GTO. The engine is an LQ4 DBW. I have the original LQ4 harness mdified to work with the E40. The engine starts and runs, but the throttle is dead. I have converted to the 06 GTO throttle pedal that was original to the PCM in the donor. I am attempting to use the LQ4 DBW throttle body.
Now to the root of the problem. As I said the throttle is completely numb, no action at all. Here is the pinout at the TB with associated voltages.
COLOR.......Function..........Circuit #.........Voltage........PCM Pin(E40)
YELLOW TAC 1 581 12V BK 63
BLK/WHT LOW REF 1704 0 BK 36
BROWN TAC 2 582 12V BK 60
BLACK LOW REF 452 0 BK 36
LT BLU/BLK 5 V REF 1688 5V BK 41
PURPLE LOW REF 486 3.7V BK 29
GREEN 5 V REF 485 0 BK 31
GRAY 5 V REF 416 5V BK 35
If I cycle the throttle pedal I see no changes at the throttle body. If I put 12V to the Yellow and ground the brown the throttle snaps open.
I also see 3 DTC's
P0122......Switch A, TP sensor low voltage
P0123......Switch A, TP sensor high voltage
P0223......Switch B cir 2, high voltage
Any ideas?
Now to the root of the problem. As I said the throttle is completely numb, no action at all. Here is the pinout at the TB with associated voltages.
COLOR.......Function..........Circuit #.........Voltage........PCM Pin(E40)
YELLOW TAC 1 581 12V BK 63
BLK/WHT LOW REF 1704 0 BK 36
BROWN TAC 2 582 12V BK 60
BLACK LOW REF 452 0 BK 36
LT BLU/BLK 5 V REF 1688 5V BK 41
PURPLE LOW REF 486 3.7V BK 29
GREEN 5 V REF 485 0 BK 31
GRAY 5 V REF 416 5V BK 35
If I cycle the throttle pedal I see no changes at the throttle body. If I put 12V to the Yellow and ground the brown the throttle snaps open.
I also see 3 DTC's
P0122......Switch A, TP sensor low voltage
P0123......Switch A, TP sensor high voltage
P0223......Switch B cir 2, high voltage
Any ideas?
You need a GTO throttle body. You can't mix gen3 dbw stuff with gen4 unless you buy a x-link
The best way is to use all components from the same donor vehicle, including pedal and TB, it will make your life much easier
The best way is to use all components from the same donor vehicle, including pedal and TB, it will make your life much easier
