P1AF5

DTC P1AF4-P1AF7

Diagnostic Instructions

* Perform the Diagnostic System Check - Vehicle Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis Strategy Based Diagnosis for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions Diagnostic Procedure Instructions provides an overview of each diagnostic category.

DTC Descriptor
DTC P1AF4
- Drive Motor 1 Control Module Hybrid Battery Voltage Isolation Sensor Circuit Low Voltage

DTC P1AF5
- Drive Motor 1 Control Module Hybrid Battery Voltage Isolation Sensor Circuit High Voltage

DTC P1AF6
- Drive Motor 2 Control Module Hybrid Battery Voltage Isolation Sensor Circuit Low Voltage

DTC P1AF7
- Drive Motor 2 Control Module Hybrid Battery Voltage Isolation Sensor Circuit High Voltage

Circuit/System Description

The drive motor generator power inverter control 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 battery energy control module 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 center 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.

Conditions for Running the DTC

* The motor control module runs the program to detect an internal fault when the key is ON.
* Ignition voltage is 8-18 V.

Conditions for Setting the DTC

P1AF4 and P1AF6

The motor control module detects isolation sensor voltage less than 0V.

P1AF5 and P1AF7

The motor control module detects isolation sensor voltage greater than 564V.

Action Taken When the DTC Sets

* DTCs P1AF4, P1AF5, P1AF6 and P1AF7 are Type B DTCs.
* The hybrid powertrain control module commands the battery energy control module to open the high voltage contactor relays.

Conditions for Clearing the DTC

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

Reference Information
DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Circuit/System Verification

1. Verify that DTC P1AE7 is not set.

• If the DTC is set, refer to DTC P1AE6 or P1AE7 P1AE6.

2. Verify that DTCs P1AF4, P1AF5, P1AF6 and P1AF7 is not set.

• If the DTC is set, program the drive motor generator power inverter module with the latest software version. If the DTC resets replace the T6 drive motor generator power inverter module.

Repair Instructions

Perform the Diagnostic Repair Verification Verification Tests after completing the diagnostic procedure.

Control Module References Control Module References for Drive Motor Generator Power Inverter replacement, setup, and programming.