Mike's Workshop Manuals: Service manuals for every vehicle
Home >> GMC >> 2008 >> Yukon Base, 4.8 C >> Repair and Diagnosis >> External Pages >> Different variant/trim >> Section 4 (Hybrid Engine Control System) >> Diagnostic Information and Procedures >> DTC P1A88 >> Circuit/System Testing

Circuit/System Testing

WARNING: This page is about a different variant/trim than selected.
  1. Turn the ignition key to the OFF position.
  2. Disconnect the 42 volt X2 harness connector at the APM.
  3. Turn the ignition key to ON. Do not go to START.
  4. Use the scan tool APM Intermediate Voltage Control under the APM special functions list to turn on the 42 volt circuit.
    • If the APM Intermediate Voltage is not between 40 and 44 volts, replace the APM.
    • If the APM Intermediate Voltage is between 40 and 44 volts, the problem is not in the APM. This DTC can set for the following external reasons: