Circuit/System Testing (Gasoline)
WARNING: This page is about a different car, the 2009 GMC Sierra, 2009 Chevrolet Silverado, and 2009 Chevrolet Cab & Chassis Silverado. 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 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 0%.
- If greater than the specified value, test the field duty cycle circuit terminal 2 X1 for a short to voltage. If the circuit tests normal, replace the ECM.
- Connect a test lamp 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%.
- 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.