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Circuit/System Testing

  1. Ignition OFF, disconnect the X1 harness connector at the K20 ECM.
  2. Ignition ON, the MIL should not illuminate.
    • If the MIL is illuminated, test the MIL control circuit terminal 46-X1 for a short to ground. If the circuit tests normal, replace the IPC.
    3. NOTE: The MIL is powered by a dedicated ignition voltage circuit.
  3. Connect a 3 A fused jumper wire between the MIL control circuit terminal 46-X1 and ground. The MIL should illuminate.
    • If the MIL illuminates, replace the ECM.
    • If the MIL does not illuminate, test the MIL control circuit for a short to voltage or an open/high resistance. If the MIL control circuit tests OK, test the cluster ignition circuit for a short to ground or open/high resistance. If the circuits test normal, replace the IPC/bulb.
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