Circuit/System Testing
WARNING: This page does not describe the selected car, but rather 8 other vehicles, including 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.
- Remove connector from the transfer case control module. With ignition ON and engine OFF, observe with the scan tool the 4WD Low parameter.
- If the scan tool indicates Enabled, test the 4WD Low signal circuit for a short to ground.
- Using the J 35616
GM-approved terminal test kit, install a fused jumper between the 4WD low signal circuit and ground at the transfer case control module connector.
- If the scan tool 4WD Low parameter indicates Enabled when grounded, replace the transfer case control module.
- Test the 4WD Low signal circuit for an open.
- Fix the open in the 4WD Low circuit.
- Replace the ECM.