Service Information

Volt

DTC P1B41 or P1B42

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 P1B41: Drive Motor 1 Control Module Hybrid/EV Battery Voltage Isolation Sensing Performance

DTC P1B42: Drive Motor 2 Control Module Hybrid/EV Battery Voltage Isolation Sensing Performance

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.

P1B41

DTC P1AE8, P1AE9, P1B0B or P1B0C is not set.

P1B42

DTC P1AEA, P1AEB, P1B43 or P1B44 is not set.

Conditions for Setting the DTC

The difference between the voltage sensed and hybrid battery voltage is greater than 40V.

And

The difference between the voltage sensed and the high voltage measured is greater than 50V.

Action Taken When the DTC Sets

•	DTCs P1B41 and P1B42 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 P1B41 and P1B42 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.