HVAC - Manual

DTC B0158

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 B0158 02
- Outside Air Temperature Sensor Circuit Short to Ground

DTC B0158 05
- Outside Air Temperature Sensor Circuit Short to Battery or Open

Diagnostic Fault Information






Circuit/System Description

The HVAC control module monitors the ambient air temperature sensor with a low reference circuit and 5 V signal circuit. The HVAC control module monitors the voltage drop across the sensor, which is proportional to temperature. When the ambient air temperatures are cold, the resistance of the sensor is high and the voltage signals are high. When the ambient air temperatures are hot, the resistance of the sensors is low and the voltage signals are low. The HVAC control module converts the voltage value to a temperature value of Celsius and Fahrenheit that will be displayed by the driver information center (DIC).

Diagnostic Aids






Conditions for Running the DTC

The ignition is turned ON.

Conditions for Setting the DTC

* The HVAC control module detects the sensor signal circuit is less than -35°C (-39°F).

* The HVAC control module detects the sensor signal circuit is more than 85°C (185°F).

Action Taken When the DTC Sets

The HVAC control module uses a default air temperature value for compressor clutch operation.

Conditions for Clearing the DTC

* The DTC will become history if the HVAC control module no longer detects a failure.

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

Reference Information

Schematic Reference

HVAC Schematics HVAC - Manual

Connector End View Reference

Component Connector End Views 1-2 Shift Solenoid (SS) Valve (M30)

Description and Operation

* Air Delivery Description and Operation Air Delivery

* Air Temperature Description and Operation Air Temperature

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 Control Module References for Scan Tool Information

Circuit/System Verification

Ignition ON, observe the ambient air temperature sensor. The reading should be between -35°C (-39°F) and 85°C (185°F) and change with ambient air temperature changes.

Circuit/System Testing

Important: If the ambient air temperature sensor is in temperatures below 2°C (35°F) the compressor clutch will be disabled until the vehicle is driven above 45 mph (72 km/h), the ignition is OFF for more than 3 hours or an instant OAT update is performed.


Important: An instant OAT update must be performed by pressing the A/C and Recirc buttons at the same time before and after the system has been serviced to update the filtered ambient air temperature sensor circuit and convert the A/C permission from withheld to granted.


1. Ignition OFF, all vehicle systems OFF, and the scan tool disconnected, disconnect the harness connector at the ambient air temp sensor. It may take up to 2 minutes for all vehicle systems to power down.

2. Test for less than 5 ohms between the low reference circuit terminal B and ground:

• If 5 ohms or greater

1. Ignition OFF, disconnect the X2 harness connector at the HVAC control module.

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 HVAC control module.

• If less than 5 ohms

3. Ignition ON.

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

• If less than 4.8 V

1. Ignition OFF, disconnect the X2 harness connector at the HVAC control module.

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 in 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 HVAC control module.

• If greater than 5.2 V

1. Ignition OFF, disconnect the X2 harness connector at the HVAC control module.

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 HVAC control module.

• If between 4.8-5.2 V

Important: An instant OAT update must be performed to grant A/C permission after testing or replacing the ambient air temperature sensor.


5. Replace the 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 HVAC control module.

• If the DTC does not set

7. All OK.

Component Testing

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

2. Measure the resistance between terminal A and terminal B.

3. Verify the resistance is within 5 % of the specified readings contained in the Sensor Resistance Table Electrical Specifications.

• If not within 5 %
Replace the ambient air temperature sensor

• If within 5 %

4. All OK.

Repair Instructions

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

* Ambient Air Temperature Sensor Replacement Service and Repair

* Control Module References Control Module References for HVAC control module replacement, programming, and setup.