LEMON Manuals: Even more car manuals for everyone
Home >> Hummer >> 2008 >> H2 4D Utility Wagon >> Repair and Diagnosis >> External Pages >> Different car >> Section 254 (Engine Control System & Fuel - 4.8L, 5.3L, 6.0L, Or 6.2L - DTC P069F To DTC P3449) >> DTC P3401, P3425, P3441, or P3449 >> Circuit/System Testing

Circuit/System Testing

WARNING: This page does not describe the selected car, but rather 8 other vehicles, including the 2008 GMC Yukon XL, 2008 GMC Yukon, 2008 Chevrolet Tahoe, 2008 Chevrolet Suburban, and 2008 Chevrolet Avalanche. However, it is still accessible from the selected car via links, so may be relevant.
IMPORTANT: You must perform the Circuit/System Verification first.
  1. Disconnect the valve lifter oil manifold (VOLM) harness connector.
  2. Ignition ON, verify that a test lamp illuminates between the ignition circuit terminal E and ground.
    • If the test lamp does not illuminate, test the ignition circuit for a short to ground or an open/high resistance. If the circuit tests normal and the ignition circuit fuse is open, test or replace the VLOM assembly.
  3. Verify that a test lamp does not illuminate between the ignition circuit terminal E and the affected control circuit terminal.
    • If the test lamp illuminates, test the control circuit for a short to ground. If the circuit tests normal, replace the ECM.
  4. Remove the test lamp.
  5. Command the affected cylinder deactivation solenoid ON with a scan tool. Verify with a scan tool that the affected cylinder deactivation solenoid Ckt. Short Volts Test Status parameter is OK.
    • If not the specified value, test the control circuit for a short to voltage. If the circuit tests normal, replace the ECM.
  6. Install a 3A fused jumper wire between the affected control circuit terminal and the ignition circuit terminal E. Command the affected cylinder deactivation solenoid ON with a scan tool. Verify with a scan tool that the affected cylinder deactivation solenoid Ckt. Short Volts Test Status parameter is displaying Fault.
    • If not the specified value, test the control circuit for an open/high resistance. If the circuit tests normal, replace the ECM.
  7. If all the circuits test normal, test or replace the VOLM assembly.
scientia non olet · About LEMON Manuals