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.
- Verify that a test lamp illuminates between the B+ circuit ring terminal 1 X2 and ground.
- If the test lamp does not illuminate, test the B+ circuit for a short to ground or an open/high resistance.
- Ignition OFF, disconnect the X1 harness connector at the generator.
- Ignition ON, verify the scan tool ECM GEN-F Terminal Signal parameter is less than 5 percent.
- If greater than the specified range, test the field duty cycle circuit terminal 2 X1 for a short to voltage. If the circuit tests normal, replace the ECM.
- Install a 3A fused jumper wire between the field duty cycle circuit terminal 2 X1 and B+. Verify the scan tool ECM GEN-F Terminal Signal parameter is greater than 95 percent.
- If less than the specified range, test the circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the ECM.
- If all circuits test normal, test or replace the generator.