LEMON Manuals: Even more car manuals for everyone
Home >> GMC >> 2006 >> Sierra 1500 HD, RWD >> Repair and Diagnosis >> External Pages >> Different car >> Section 1377 (Engine Controls And Fuel - 4.3L - DTC P0340 To DTC P2138) >> DTC P1682 >> Circuit/System Testing >> Testing the Ignition 1 Signal Circuit

Testing the Ignition 1 Signal Circuit

WARNING: This page is about a different car, the 2009 GMC Sierra and 2009 Chevrolet Silverado. However, it is still accessible from the selected car via links, so may be relevant.
    IMPORTANT: A resistance of 5 ohms or greater in the circuit will cause the DTC to set.
  1. 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.
  2. Ignition OFF, disconnect the ECM C1 connector.
  3. Ignition ON, verify that B+ is available at C1-19.
    • 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.
  4. If all circuits test normal, replace the ECM.
scientia non olet · About LEMON Manuals