Circuit/System Testing
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- 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.
- Ignition OFF, disconnect the X4 harness connector at the BCM.
- 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.
- If all circuits tests normal, replace the BCM.