LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Buick >> 2009 >> Allure Super >> Repair and Diagnosis >> Engine Performance >> System >> Engine Control System & Fuel System - 5.3L - DTC P0420 To DTC P3449 >> DTC P3401, P3425, P3441, or P3449 >> Circuit/System Testing >> Notes
April 5, 2026: LEMON Manuals is launched! Read the announcement.

Circuit/System Testing: Notes

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