Volt

DTC P1AF4-P1AF7

The power inverter module, often referred to as the drive motor generator power inverter module, contains two motor control modules. Each motor control module measures hybrid battery high voltage with several internal sensors. The motor control modules test for loss of isolation between either the high-voltage positive circuit or high-voltage negative circuit and vehicle chassis. The motor control modules test for isolation when the high-voltage contactor relays are closed. The hybrid powertrain control module 2 only tests the hybrid battery assembly for high-voltage loss of isolation when the high-voltage contactor relays are open.

Motor control module loss of isolation is detected through the use of two high-impedance resistors and voltage measuring circuitry. The two resistors are connected in series between the high- voltage positive and high-voltage negative circuits. The centre connection of the two resistors is also connected to vehicle chassis. The motor control module then measures the voltage drop across one of the resistors. Without a loss of isolation, the motor control module should measure about half of the high voltage potential. This is referred to as mid-pack voltage. The Mid-pack voltage value is then doubled by the software and displayed on a scan tool as Motor 1 Isolation Voltage or Motor 2 Isolation Voltage. When a loss of isolation is present, the motor isolation voltage display will indicate voltage that is more or less than actual hybrid battery high voltage. The motor control module monitors the loss of isolation voltage measuring circuitry for correct operation.

P1AF4 and P1AF6

P1AF5 and P1AF7

P1AF4 and P1AF6

The motor control module detects isolation sensor voltage less than 20V.

P1AF5 and P1AF7

The motor control module detects the value of the mid-pack voltage subtracted from the pack voltage is greater than 40V.

DTCs P1AF4, P1AF5, P1AF6 and P1AF7 are Type B DTCs.

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

1. Verify that DTC P0AA6 is not set.

⇒	If the DTC is set, refer to DTC P0AA6, P1AE6 or P1F0E .

2. Verify that DTCs P1AF4, P1AF5, P1AF6 or P1AF7 are not set.

⇒	If the DTC is set, program the T6 power inverter module with the latest software version. If the DTC resets replace the T6 power inverter module.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Control Module References for Drive Motor Generator Power Inverter Module, also called the power inverter module, replacement, programming and set-up.