Volt

DTC P0A2B-P0A2D or P0A31-P0A33

The motor temperature sensor is a non-serviceable part of the power inverter module, often referred to as the drive motor generator assembly. The motor temperature sensor is a thermistor, or a resistor that changes value when the temperature changes. The sensor has a negative-temperature coefficient. This means that as the temperature increases, the resistance decreases, and as the temperature decreases, the resistance increases. The motor control module supplies a 5 V reference signal to the sensor and measures the voltage drop in the circuit. When the motor is cold, the sensor resistance is high and the motor control module detects high signal voltage. As the motor temperature increases, the resistance of the sensor decreases, which lowers the signal voltage.

P0A2B and P0A31

P0A2C and P0A32

Vehicle is ON or the power inverter module is awake.

P0A2D and P0A33

Vehicle has been driven for at least 90 seconds.

P0A2B and P0A31

The Motor temperature is more than 20°C (36°F) greater than the average of the Transmission Fluid Temperature and the power inverter module temperatures.

P0A2C and P0A32

Motor temperature sensor signal is greater than 184°C (363°F) for 3 seconds.

P0A2D and P0A33

Motor temperature sensor signal is less than -41°C (-42°F) when drive motor generator torque is greater than 20 N·m (15 lb ft) for 90 seconds.

DTCs P0A2B-P0A2D, P0A31-P0A33 are Type A DTCs.

DTCs P0A2B-P0A2D, P0A31-P0A33 are Type A DTCs.

Schematic Reference

Hybrid Controls Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

Drive Motor Generator Power Inverter Module Description and Operation

Electrical Information Reference

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

Control Module References for scan tool information

Special Tools

DT-44152 Jumper Harness, 20 terminal

For equivalent regional tools, refer to Special Tools .

P0A2B and P0A31

1. Allow the vehicle to cool to ambient temperature by leaving the vehicle OFF and not connected to a charger for at least 6 hours.
2. Vehicle ON, observe Motor 1 temperature, Motor 2 temperature, Transmission Fluid Temperature and Power Inverter Module Temperature scan tool parameters.

⇒	All temperature parameters should be within 28°C (50°F) of each other and ambient temperature.

P0A2C, P0A2D, P0A32, and P0A33

Vehicle ON, observe the motor control modules motor temperature scan tool parameter.

1. Vehicle OFF, disconnect the transmission X175 20-way harness connector.

Note: The vehicle must be ON to test the low reference circuit. Other DTCs will set with the X175 connector disconnected.

2. Connect DT-44152 jumper harness to the vehicle harness side only.
3. Vehicle ON, test the jumper harness side for less than 8 ohms between the low reference circuit terminals listed below and earth for the appropriate drive motor generator:

•	Drive motor 1 low reference circuit terminal S

•	Drive motor 2 low reference circuit terminal H

⇒	If greater than the specified range, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the T6 power inverter module.

4. Vehicle ON, verify the scan tool motor temperature sensor parameter is less than -41°C (-42°F).

⇒	If more than the specified value, test the motor temperature sensor signal circuit for a short-circuit to earth. If the circuit tests normal, replace the T6 power inverter module.

5. Install a 3-amp fused jumper wire between the signal circuit terminal and the low reference circuit terminal listed below for the appropriate drive motor generator. Verify the scan tool motor temperature sensor parameter is greater than 184°C (363°F):

•	Drive motor 1 terminals K and S

•	Drive motor 2 terminals J and H

Note: If a short-circuit to voltage is found, test the motor temperature sensor for an open circuit or physical damage.

⇒	If less than the specified value, test the signal circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the T6 power inverter module.

6. Vehicle OFF, connect the DT-44152 jumper harness to the X175 transmission 20-way connector at the transmission. Measure and record the resistance between the sensor signal and low reference terminals. Compare the actual sensor and circuit resistance to the expected sensor resistance. Refer to Temperature Versus Resistance .

⇒	If the resistance is near the expected value, test the transmission internal harness signal circuit for a short-circuit to earth. If the circuit tests normal, replace the M15 drive motor.

⇒	If the resistance is not near the expected value, test the transmission internal harness signal and low reference circuits for an open or shorted together condition. If the circuits test normal, replace the M15 drive motor.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.