P1B0B

DTC P1B0B or P1B0C

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 P1B0B
- Drive Motor 1 Control Module Hybrid/EV Battery Voltage Isolation Sensing Circuit 2 Low Voltage

DTC P1B0C
- Drive Motor 1 Control Module Hybrid Battery Voltage Isolation Sensing Circuit 2 High Voltage

Circuit/System Description

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 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 vehicle is ON.

P1B0C

DTC P1AE8 or P1AE9 is not set.

Conditions for Setting the DTC

P1B0B

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

P1B0C

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

Action Taken When the DTC Sets

* DTCs P1B0B and P1B0C 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 P1B0B and P1B0C are Type B DTCs.

Reference Information
Schematic Reference

Hybrid Controls Schematics Hybrid Controls Schematics
Connector End View Reference

Component Connector End Views Hybrid/EV Battery Pack X1
Electrical Information Reference

* Circuit Testing Circuit Testing
* Connector Repairs Connector Repairs
* Testing for Intermittent Conditions and Poor Connections Testing for Intermittent Conditions and Poor Connections
* Wiring Repairs Wiring Repairs

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions Powertrain Diagnostic Trouble Code (DTC) Type Definitions
Scan Tool Reference

Control Module References Programming and Relearning for scan tool information

Repair Instructions

If DTC P1B0B or P1B0C is set, refer to Loss of Isolation on the High Voltage Main Bus Loss of Isolation on the High Voltage Main Bus.

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