The stock wiring harness on the 05 GTO ls2 fits the z-car very good. The harness only needs 2 hots added. All of the other wiring is done on the Blue J1 plug, this is a plug that plugs into the ecu and is separate from the engine harness. You will find everything you need in this plug. the TBW will also be in this plug I think it is 4 wires and you extend them to the TBW pedal.
ULISES Can you post some pictures of the ecu and wires and TBW pedal.
Pin - Wire Color - Function
1 TN/BK High Speed GMLAN Serial Data Bus+
2 TN High Speed GMLAN Serial Data Bus-
3 Not Used
4 BN/WH Check Engine Indicator Lamp Output
5 Not Used
6 Not Used
7 BN Electronic Throttle Pedal Position Return 1
8 PU Electronic Throttle Pedal Position Return 2
9 Not Used
10 BN Engine Control Relay Coil Control
11 Not Used
12 Not Used
13 YE Starter Relay Output-Coil
14 PK Ignition 1 Voltage
15 Not Used
16 Not Used
17 Not Used
18 YE Accessory Voltage
19 OG Ignition 3 Voltage
20 OG/BK Battery Positive Voltage
21 PU/WH VSS Signal
22 BU Electronic Throttle Pedal Position Signal 1
23 Not Used
24 GN Fuel Tank Pressure Sensor Signal
25 Not Used
26 GN/BK A/C Refrigerant Pressure Sensor Signal
27 Not Used
28 Not Used
29* TN Electronic Throttle Pedal Position 5-Volt Reference 2
30 GN A/C Refrigerant Pressure Sensor Signal 5-Volt Reference
31 GY Fuel Tank Pressure Sensor 1, 5-Volt Reference
32 BU/RD Stop Lamp Switch Signal
33 Not Used
34 Not Used
35 WH/BK Electronic Throttle Pedal Position 5 Volt Reference 1
36 OG/BK Low Speed Cooling Fan Relay Control
37 PU Fuel Gage Sensor Signal
38 GY Extended Travel Brake Switch Signal
39 Not Used
40 Not Used
41 L-BU Electronic Throttle Pedal Position 2
42 YE Reverse Lockout Solenoid Control
43 PU/WH CPP Switch Signal
44 Not Used
45 GN/WH Fuel Pump Relay Feed-Coil
46 BN Cruise Control Release Signal
47 Not Used
48* BN/RD Tachometer Signal
49 Not Used
50 Not Used
51 GN/BU Park/Neutral Position Switch Park Signal
52 PU Crank Voltage
53 Not Used
54* WHT To BCM Connection 1 position 16
55 TN A/C Refrigerant Pressure Sensor Signal
56 BU/WH High Speed Cooling Fan Relay Control
* Denotes a difference from the Factory Service Manual (FSM) and my harness.
29 FSM has the color listed as TH instead of TN.
48 FSM doesn't list the red stripe (BN/RD), only listed as solid brown (BN).
54 Is listed as Not Used. I split open the loom and followed it to the Body Control Module (BCM).
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