Component Testing
WARNING: This page is about a different car, the 2011 GMC Yukon XL, 2011 GMC Yukon, 2011 Chevrolet Tahoe, 2011 Chevrolet Suburban, and 2011 Chevrolet Avalanche. However, it is still accessible from the selected car via links, so may be relevant.
Front Drive Axle Actuator (FDAA)
- Key OFF. Disconnect the X1 connector at the FDAA.
- Remove the FDAA.
- Connect the FDAA X1 connector. Position the FDAA so that it is visible from the side of the vehicle.
- Using the Engage Front Axle function of the Special Function feature of the scan tool, command the front axle ON and OFF. When commanded ON the plunger on the FDAA should extend. When commanded OFF the plunger should retract.
- If the FDAA does not perform as described, replace the FDAA.
- Refer to Front Axle Will Not Engage , or Front Axle Will Not Disengage .
Transfer Case Shift Control Module (TCCM)
- Key OFF. Disconnect the X1 connector at the front drive axle actuator (FDAA).
- Key ON, engine OFF. Install a scan tool.
- Using the GY probe J 35616-2A, connect a test light between the Ignition 1 voltage circuit, FDAA X1 harness pin C and the front axle actuator control circuit, FDAA X1 harness pin B.
- Using the Engage Front Axle function of the Special Function feature of the scan tool, command the front axle ON and OFF. When commanded ON the test light should illuminate. When commanded OFF the test light should turn OFF.
- If the TCCM does not perform as described, replace the TCCM.
- Go to Circuit/System Verification.
NOTE:
When test probing harness terminals, it is imperative to use the proper test probe from the most current version of the J 35616 Kit. Use of an improper test probe may deform the terminal, resulting in intermittent open conditions.