LEMON Manuals: Even more car manuals for everyone
Home >> Hummer >> 2008 >> H2 4D Utility Wagon >> Repair and Diagnosis >> External Pages >> Different car >> Section 255 (Engine Control System & Fuel - Hybrid (Hp2) 6.0L (LFA) - DTC P0700 To DTC P3449) >> DTC P1682 >> Circuit/System Testing

Circuit/System Testing

WARNING: This page is about a different car, the 2008 GMC Yukon and 2008 Chevrolet Tahoe. However, it is still accessible from the selected car via links, so may be relevant.
IMPORTANT: You must perform the Circuit/System Verification before proceeding with Circuit/System Testing.

Testing the Ignition 1 Signal Circuit

  1. Ignition OFF, open the hood to disable the Auto-Stop function. Refer to Hybrid Modes of Operation Description .
  2. Ignition ON, verify the scan tool hood position parameter displays Open.
    3. IMPORTANT: A resistance of 5 ohms or greater in the circuit will cause the DTC to set.
  3. Ignition ON, verify that B+ is available to both test points of the fuse from the powertrain relay to the ECM.
    • If B+ is only available on one test point of the fuse, test the ignition 1 voltage circuit from the fuse to the ECM for a short to ground. If the circuit tests normal, replace the ECM.
    • If B+ is not available on either test point of the fuse, replace the underhood fuse block.
  4. Ignition OFF, disconnect the ECM X1 connector.
  5. Ignition ON, verify that B+ is available at X1-19.
    • If B+ is not available, test the ignition 1 voltage circuit for an open/high resistance condition. If the circuit tests normal, replace the ECM.
  6. If all circuits test normal, replace the ECM.

Testing the EC Ignition Relay Feedback Circuit

    IMPORTANT: A resistance of 5 ohms or greater in the circuit will cause the DTC to set.
  1. Ignition OFF, remove the powertrain relay from the underhood fuse block.
  2. Ignition ON, connect a 3A fused jumper wire from B+ to the powertrain ignition 1 voltage circuit terminal. Verify that the EC Ignition Relay Feedback parameter displays B+ on the scan tool.
    • If the scan tool parameter is less than the specified value, test the ignition 1 voltage circuit for an open/high resistance or short to ground. If the circuit tests normal, replace the ECM.
scientia non olet · About LEMON Manuals