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Home >> Cadillac >> 2018 >> CT6 Plug-In >> Repair and Diagnosis >> Hybrid/Electric Powertrain >> Electric Converters and Controllers >> Hybrid/EV Control System >> Diagnostic Information and Procedures >> DTC P1904-P1907 >> Circuit/System Testing
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Circuit/System Testing

    NOTE:

    If the a/trans wiring harness assembly circuits fail the circuit tests, replace the harness; do not repair.

  1. Vehicle OFF, disconnect the X175 harness connector at the transmission.
  2. Vehicle ON.
  3. Test for 7.8 - 8.6 V between the circuit terminals listed below:
    • Terminal 31 and 36
    • Terminal 34 and 35
    • If less than 7.8 V 
    1. Vehicle OFF, disconnect the X1 harness connector at the T6 Power Inverter Module.
    2. Test for infinite resistance between the circuit and ground.
      • If less than infinite resistance, repair the short to ground on the circuit.
      • Go to next step: If infinite resistance
    3. Test for less than 2 Ω in the circuit end to end.
      • If 2 Ω or greater, repair the open/high resistance in the circuit.
      • If less than 2 Ω, replace the T6 Power Inverter Module.
    • If greater than 8.6 V 
    1. Vehicle OFF, disconnect the X1 harness connector at the T6 Power Inverter Module, Vehicle ON.
    2. Test for less than 1 V between the circuit and ground.
      • If 1 V or greater, repair the short to voltage on the circuit.
      • If less than 1 V, replace the T6 Power Inverter Module.
    • Go to next step: If between 7.8 - 8.6 V 
  4. Vehicle OFF, disconnect the harness connector at the B228A Drive Motor 1 Position Sensor. Connect the X175 harness connector at the transmission. Vehicle ON.
  5. Test for 7.8 - 8.6 V between the circuit terminals listed below:
    • Terminal A and B
    • Terminal C and D
      • If not between 7.8 - 8.6 V, replace the a/trans wiring harness assembly.
      • If between 7.8 - 8.6 V, replace the B228A Drive Motor 1 Position Sensor.
  6. Verify DTC P0A3F, P0C52, P0C53, P0C5C, or P0C5D is not set.
    • If any of the DTCs are set 
    1. Verify the T6 Power Inverter Module has the latest calibration in Calibration Information.
      • If the T6 Power Inverter Module does not have the latest calibration, program the T6 power inverter module.
      • If the T6 Power Inverter Module has the latest calibration, replace the T6 Power Inverter Module.
    2. Verify the DTC does not set.
      • If the DTC sets, replace the T6 Power Inverter Module.
      • Go to next step: If the DTC does not set
    3. All OK.
    • Go to next step: If none of the DTCs are set 
  7. All OK.
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