2003 GMC Yukon – Wiring Diagram
Locate the BCM
The BCM is directly under the steering column. The dash trim under the column needs to be removed and the knee bolster must come off to get at the BCM.
Caution: Unless directed otherwise, the ignition and start switch must be in the OFF or LOCK position, and all electrical loads must be OFF before servicing any electrical component. Disconnect the negative battery cable to prevent an electrical spark should a tool or equipment come in contact with an exposed electrical terminal. Failure to follow these precautions may result in personal injury and/or damage to the vehicle or its components.
For Vehicles equipped with OnStar® (UE1) with Back Up Battery:
The Back Up Battery is a redundant power supply to allow limited OnStar® functionality in the event of a main vehicle battery power disruption to the VCIM (OnStar®module). Do not disconnect the main vehicle battery or remove the OnStar® fuse with the ignition key in any position other than OFF. Retained accessory power (RAP) should be allowed to time out or be disabled (simply opening the driver door should disable RAP) before disconnecting power. Disconnecting power to the OnStar® module in any way while the ignition is On or with RAP activated may cause activation of the OnStar® Back-Up Battery (BUB) system and will discharge and permanently damage the back-up battery. Once the Back-Up Battery is activated it will stay on until it has completely discharged. The BUB is not rechargeable and once activated the BUB must be replaced.
Install the VATS Passkey Passlock Full Bypass
There are 6 electrical connectors on the BCM (C1, C2, C3, C4, C5 and C6). For the installation of the Full Bypass you will need to work only on C2 and C3
To install the Full bypass connect it in the following way:
- T1/RED wire : leave unconnected
- T2/BLK wire: tap on BCM C2 Pin B7 (BLK)
- T3/DK-GRN wire: leave unconnected.
- T4/YEL: Cut the wire on BCM C3 Pin A6 (YEL) and connect on the side of the BCM connector.
- T5/BLU wire: leave unconnected.
Perform the re-learning procedure
- Turn ON the ignition, with the engine OFF.
- Attempt to start the engine, then release the key to ON (vehicle will not start).
- Observe the SECURITY light, after approximately 11 minutes the light will turn OFF.
- Turn OFF the ignition, and wait 10 seconds.
- Repeat steps 1 through 4 two more times for a total of 3 cycles/30 minutes ( the vehicle
is now ready to relearn the Sensor Data Code and/or passwords on the next ignition switch transition from OFF to CRANK).
Important: The vehicle learns the relearns Sensor Data Code and/or password on the next ignition switch transition from OFF to CRANK. You must turn the ignition OFF before attempting to start the vehicle.
Start the engine (the vehicle has now learned the Sensor Data Code and/or password).
The installation is completed.