P0072

DTC P0071-P0073

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 Descriptors

DTC P0071
- Ambient Air Temperature Sensor Performance

DTC P0072
- Ambient Air Temperature Sensor Circuit Low Voltage

DTC P0073
- Ambient Air Temperature Sensor Circuit High Voltage

Diagnostic Fault Information






Circuit/System Description

The Hybrid/EV Powertrain Control Module 2 supplies the ambient air temperature sensor with a low reference circuit and 5 V signal circuit. The Hybrid/EV Powertrain Control Module 2 determines the voltage drop across the sensor, which is proportional to temperature. As the air temperature increases, the sensor resistance decreases. As the air temperature decreases, the sensor resistance increases.

Conditions for Running the DTC

Vehicle in Service Mode.

Conditions for Setting the DTC

The Hybrid/EV Powertrain Control Module 2 detects the ambient air temperature sensor signal circuit is less than -35°C (-39°F) or more than 85°C (185°F) for more than 15 seconds.

Action Taken When the DTC Sets

* The DIC will display SERVICE A/C SYSTEM.

* The system operates using a default value.

Conditions for Clearing the DTC

* The DTC will become history if the Hybrid/EV Powertrain Control Module 2 no longer detects the condition that set the DTC.

* The history DTC will clear after 100 fault-free ignition cycles.

Reference Information

Schematic Reference

HVAC Schematics Electrical Diagrams

Connector End View Reference

Component Connector End Views Hybrid/EV Battery Pack X1

Description and Operation

Automatic HVAC Description and Operation HVAC - Automatic

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

Scan Tool Reference

Control Module References Programming and Relearning for scan tool information

Circuit/System Testing

1. Vehicle OFF, disconnect the harness connector at the B9 ambient air temperature sensor.

2. Verify a test lamp illuminates between the low reference circuit terminal B and B+.

• If the test lamp does not illuminate

1. Vehicle OFF disconnect the harness connector X1 at the K114B hybrid powertrain control module 2

2. Test for less than 2 ohms in the low reference circuit end to end.

• If 2 ohms or greater, repair the open/high resistance in the circuit.

• If less than 2 ohms replace the K114B hybrid powertrain control module 2

• If the test lamp illuminates

3. Vehicle in Service Mode.

4. Test for 4.8-5.2 V between the signal circuit terminal A and ground.

• If less than 4.8 V

1. Vehicle OFF, disconnect the harness connector X1 at the K114B hybrid powertrain control module 2.

2. Test for infinite resistance between the signal circuit and ground.

• If less than infinite resistance repair the short to ground on the circuit.

• If infinite resistance

3. Test for less than 2 ohms on the signal circuit end to end.

• If 2 ohms or greater repair the open/high resistance in the circuit.

• If less than 2 ohms replace the K114B hybrid powertrain control module 2.

• If greater than 5.2 V

1. Vehicle OFF, disconnect the X1 harness connector at the K114B hybrid powertrain control module 2, Vehicle in Service Mode.

2. Test for less than 1 V between the signal circuit and ground.

• If 1 V or greater repair the short to voltage on the circuit.

• If less than 1 V replace the hybrid powertrain control module 2.

• If between 4.8-5.2 V

5. Test or replace the B9 ambient air temperature sensor.

6. Verify the DTC does not set while operating the vehicle under the Conditions for Running the DTC.

• If the DTC sets
Replace the K114B hybrid powertrain control module 2

• If the DTC does not set

7. All OK

Repair Instructions

Perform the Diagnostic Repair Verification Verification Tests after completing the repair.

* Ambient Air Temperature Sensor Replacement Ambient Air Temperature Sensor Replacement

* Control Module References Programming and Relearning for Hybrid/EV Powertrain Control Module 2 replacement, programming and setup