Service Information

Volt

DTC P1B43 or P1B44

Diagnostic Instructions

•	Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.

•	Review Strategy Based Diagnosis for an overview of the diagnostic approach.

•	Diagnostic Procedure Instructions provides an overview of each diagnostic category.

DTC P1B43: Drive Motor 2 Control Module Hybrid/EV Battery Voltage Isolation Sensor Circuit 2 Low Voltage

DTC P1B44: Drive Motor 2 Control Module Hybrid/EV Battery Voltage Isolation Sensor Circuit 2 High Voltage

Circuit/System Description

The power inverter module, often referred to as the drive motor generator power inverter module, contains two drive motor control modules. Each drive motor control module monitors its internal high voltage sensor for correct operation, no external circuits are involved. The modules listed below are part of the power inverter module and are not serviced separately:

•	Hybrid powertrain control module

•	Motor control module 1

•	Motor control module 2

•	Auxiliary transmission fluid pump control module

Conditions for Running the DTC

•	The vehicle is ON.

•	The system voltage is 8-18 V.

•	The high voltage contactor relays are closed.

Conditions for Setting the DTC

P1B43

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

P1B44

The drive motor control module detects isolation sensor voltage greater than 40 V.

Action Taken When the DTC Sets

•	DTCs P1B43 and P1B44 are Type B DTCs.

•	The hybrid powertrain control module requests the hybrid powertrain control module 2 to open the high-voltage contactor relays.

Conditions for Clearing the DTC

DTCs P1B43 and P1B44 are Type B DTCs.

Reference Information

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Circuit/System Verification

If the DTC is set, program the T6 power inverter module. If the DTC resets, replace the T6 power inverter module.

Repair Instructions

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.