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Home >> Cadillac >> 2009 >> STS Base, 3.6 V, AWD >> Repair and Diagnosis >> External Pages >> Different car >> Section 138 (Data Communication System) >> Diagnostic Information and Procedures >> DTC U1814 >> Circuit/System Testing
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Circuit/System Testing

WARNING: This page is about a different car, the 2009 Saturn Outlook, 2009 GMC Acadia, 2009 Chevrolet Traverse, and 2009 Buick Enclave. However, it is still accessible from the selected car via links, so may be relevant.
  1. Ignition OFF, disconnect the X1 harness connector at the ECM and the TCM one at a time. After each disconnect, test for current DTCs. DTC U1814 should remain current.
    • If the DTC becomes history, replace the module disconnected when the DTC became history.
  2. Ignition OFF, disconnect the X4 harness connector at the BCM.
  3. Test for infinite resistance between the signal circuit terminal 19 and ground.
    • If less than the specified value, test the signal circuit for a short to ground.
  4. If all circuits tests normal, replace the BCM.
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