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 Descriptor
DTC P0A2B: Drive Motor 1 Temperature Sensor PerformanceDTC P0A2C: Drive Motor 1 Temperature Sensor Circuit Low Voltage
DTC P0A2D: Drive Motor 1 Temperature Sensor Circuit High Voltage
DTC P0A31: Drive Motor 2 Temperature Sensor Performance
DTC P0A32: Drive Motor 2 Temperature Sensor Circuit Low Voltage
DTC P0A33: Drive Motor 2 Temperature Sensor Circuit High Voltage
Diagnostic Fault Information
Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance |
|---|---|---|---|---|
Motor Temperature Sensor Signal | P0A2C, P0A32 | P0A2D, P0A33 | P0A2D, P0A33 | P0A2B, P0A31 |
Motor Temperature Sensor Low Reference | -- | P0A2D, P0A33 | -- | P0A2B, P0A31 |
Typical Scan Tool Data
Circuit | Short to Ground | Open | Short to Voltage |
|---|---|---|---|
Operating Conditions: Ignition ON Parameter Normal Range: 0.29V to 4.43V | |||
Motor Temperature Signal | 0.00V | 4.45V | Sensor Damage Possible |
Motor Temperature Sensor Low Reference | -- | 4.45V | -- |
Circuit/System Description
The motor temperature sensor (MTS) is a non-serviceable part of the drive motor generator assembly. The MTS 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 (MCM) supplies about a 5-volt 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 MCM detects high signal voltage. As the motor temperature increases, the resistance of the sensor decreases, which lowers the signal voltage.
Conditions for Running the DTC
P0A2B and P0A31
| • | DTCs P0A2C, P0A2D, P0AEF, P0AF0, P0BD3, P0BD4, P0BDD, P0BDE are not set. |
| • | Ignition ON after the engine has been OFF for at least 6 hours. |
| • | Average of phase U, V, W inverter temperatures is greater than -12°C (+10°F). |
| • | Motor temperature is greater than -40°C (-40°F). |
P0A2C, P0A2D, P0A32 and P0A33
The ignition is ON.
Conditions for Setting the DTC
P0A2B and P0A31
| • | The average of the three motor phase sensor temperatures and the motor temperature are not within 28°C (50°F) of each other at ignition ON. |
| • | The DTC sets within 3 seconds when the above condition is met. |
P0A2C and P0A32
| • | Motor temperature sensor signal is less than 0.29V. |
| • | The DTC sets within 3 seconds when the above condition is met. |
P0A2D and P0A33
Motor temperature sensor signal is greater than 4.42V.
| ⇒ | If this condition is observed at Ignition ON, the drive motor generator must operate at greater than 20 N·m (14.75 lb ft) of torque for a cumulative time of 1.5 minutes before the DTC will set. |
| ⇒ | If this condition is observed after Ignition ON, the DTC will set within 3 seconds when the above condition is met. |
Action Taken When the DTC Sets
| • | DTCs P0A2B-P0A2D, P0A31-P0A33 are Type B DTCs. |
| • | The HPCM commands the SERVICE HYBRID SYSTEM message to display on the instrument panel. |
Conditions for Clearing the DTC
DTCs P0A2B-P0A2D, P0A31-P0A33 are Type B DTCs.
Diagnostic Aids
| • | The motor temperature sensor can be damaged by excessive electric current. Test the sensor for an open condition whenever a short to voltage condition is observed. |
| • | Test the X176 transmission 24-way connector for proper terminal contact whenever an open or high resistance circuit condition is observed. |
| • | The HPCM motor temperature scan tool parameter display will default to 120°C (248°F) whenever an open or shorted signal circuit is observed. |
Reference Information
Schematic Reference
Connector End View Reference
Description and Operation
Drive Motor Generator Control 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-48493 Jumper Harness, 24 terminal
Circuit/System Verification
P0A2B and P0A31
- Allow the vehicle to cool to ambient temperature by leaving the ignition OFF for 6 or more hours.
- Ignition ON, observe Motor 1 temperature, Motor 2 temperature, and phase U, V, W inverter temperature scan tool parameters.
| ⇒ | The Motor 1 Temperature, Motor 2 Temperature, and phase U, V, W inverter temperature parameters should be within 28°C (50°F) of each other and ambient temperature. |
P0A2C, P0A2D, P0A32, and P0A33
Ignition ON, observe the MCM motor temperature scan tool parameter.
| ⇒ | The motor temperature parameter should be between 0.29V and 4.42V. |
Circuit/System Testing
- Ignition OFF, disconnect the transmission X176 24-way harness connector.
- Ignition ON, test the vehicle harness side for less than 8 ohms between the low reference circuit terminal and ground.
- Ignition ON, verify the scan tool motor temperature sensor parameter is greater than 4.42V.
- Install a 3-amp fused jumper wire between the signal circuit terminal and the low reference circuit terminal. Verify the scan tool motor temperature sensor parameter is less than 0.29V.
- Connect the DT-48493 to the X176 transmission 24-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 .
Important: The ignition must be ON to test the low reference circuit. Other DTCs will set with the X176 connector disconnected.
| ⇒ | If greater than the specified range, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the PIM. |
| ⇒ | If less than the specified value, test the signal circuit for a short to ground. If the circuit tests normal, replace the PIM. |
Important: If a short to voltage is found, test the motor temperature sensor for damage.
| ⇒ | If greater 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 PIM. |
| ⇒ | If the resistance is near the expected value, test the transmission internal harness signal circuit for a short to ground. If the circuit tests normal, replace the drive motor w/generator. |
| ⇒ | 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 drive motor w/generator. |
Repair Instructions
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
| • | Control Module References for PIM replacement, setup, and programming |
