LEMON Manuals: Even more car manuals for everyone
Home >> Hummer >> 2008 >> H2 4D Utility Wagon >> Repair and Diagnosis >> External Pages >> Different car >> Section 508 (Engine Controls/Fuel - 5.3L, 6.0L, 6.2L - DTC P0420 To DTC P3449 And Diagnostic Information And Procedures) >> Diagnostic Information and Procedures >> Cylinder Deactivation (Active Fuel Management) System Diagnosis >> Circuit/System Testing

Circuit/System Testing

WARNING: This page does not describe the selected car, but rather 8 other vehicles, including the 2012 GMC Yukon XL, 2012 GMC Yukon, 2012 Chevrolet Tahoe, 2012 Chevrolet Suburban, and 2012 Chevrolet Avalanche. However, it is still accessible from the selected car via links, so may be relevant.
  1. Ignition OFF, remove the valve lifter oil manifold assembly ignition fuse from the underhood fuse block.
    2. NOTE:

    Probe each terminal at the underhood fuse block with a test lamp connected to ground to determine what terminal to connect the DMM. The test lamp should not illuminate on the circuit that needs to be tested.

  2. Connect a DMM between the ignition circuit fuse terminal going to the valve lifter oil manifold assembly and the ECM housing.
  3. Ignition ON, command each Cylinder 1, 4, 6, and 7 Deactivation solenoid ON and OFF with the scan tool. Verify the resistance of each solenoid is between 11-18 Ω with the solenoid commanded ON.
    • If greater than the specified range for all cylinder deactivation solenoids, test the ignition circuit for an open/high resistance.
    • If greater than the specified range for one or more but not all cylinder deactivation solenoids, test both the control circuit and ignition circuit for an open/high resistance or an open/high resistance in the cylinder deactivation solenoid. If the circuits and solenoid test normal replace the engine control module.
  4. If all circuits and components test normal, refer to Cylinder Deactivation (Active Fuel Management) Valve Lifter Oil Manifold Diagnosis and Testing for further mechanical diagnosis of valve lifter oil manifold assembly.
scientia non olet · About LEMON Manuals