Volt

DTC P0BFD or P0BFE

The power inverter module, often referred to as the drive motor generator power inverter module, contains the motor control modules and the hybrid powertrain control module. Each motor control module operates its respective drive motor based upon hybrid powertrain control module commands. Each motor control module controls the speed, direction and output torque of its respective drive motor generator through the sequencing actuation of high-current switching transistors called insulated gate bipolar transistors. Each drive motor generator operates utilising 3-phase alternating current AC electricity. Each insulated gate bipolar transistor operates a single phase of the drive motor generator. Each phase is individually identified as U, V and W. Each motor control module monitors the current of each phase in order to detect power inverter module over-current conditions.

Because all the motor generator phase circuits are electrically joined together, they should each flow about the same amount of current. The motor control modules perform a mathematical calculation to verify that the phase current sensors are accurate. If the U-V-W phase current sensors indicate about the same amount of phase current, the sum of the calculation should be near zero. If the U-V-W phase currents are not similar, this DTC will set.

The sum of the 3-phase current sensors is greater than 156 A.

DTCs P0BFD and P0BFE are Type A DTCs.

Schematic Reference

Hybrid Controls Schematics

Electrical Information Reference

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

If the DTC is set, clear DTC; Turn the vehicle OFF for 2 minutes. Turn vehicle ON, Operate vehicle within conditions for running and setting DTC. If the DTC resets, go to Circuit/System Testing.

Danger: Always perform the High-Voltage Disabling procedure prior to servicing any High Voltage component or connection. Personal Protection Equipment (PPE) and proper procedures must be followed.

The High-Voltage Disabling procedure will perform the following tasks:

•	Identify how to disable high voltage.

•	Identify how to test for the presence of high voltage.

•	Identify conditions under which high voltage is always present and personal protection equipment (PPE) and proper procedures must be followed.

Failure to follow the procedures exactly as written may result in serious injury or death.
1. Perform the High Voltage Disabling procedure for servicing at the power inverter control module cable connections.
2. Remove the 3-phase cable assembly from the T6 power inverter module distribution box. Refer to Drive Motor Generator Rotor and Stator Removal - Unit A and Drive Motor Generator Rotor and Stator Removal - Unit B .
3. Test for infinite resistance between each of the AC circuit terminals listed below and earth:

•	X5 drive motor 1 phase U terminal

•	X5 drive motor 1 phase V terminal

•	X5 drive motor 1 phase W terminal

•	X6 drive motor 2 phase U terminal

•	X6 drive motor 2 phase V terminal

•	X6 drive motor 2 phase W terminal

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If not the specified value and the engine was running then stalled when the DTC set, test the AC circuit for a short-circuit to earth or a short-circuit between the AC circuit terminals and the aluminium cable mounting block. If the circuit tests normal, replace the appropriate M15 drive motor. If the DTC resets replace the T6 power inverter module.

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If not the specified value, and the engine would not crank when the DTC set, test the AC circuit for a short-circuit to earth or a short-circuit between the AC circuit terminals and the aluminium cable mounting block. If the circuit tests normal, replace the T6 power inverter module. If the DTC resets replace the M15 drive motor.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.