HVAC - Automatic
DTC B0158
Diagnostic Instructions
* Perform the Diagnostic System Check - Vehicle (Initial Inspection and Diagnostic Overview) prior to using this diagnostic procedure.
* ReviewStrategy Based Diagnosis (Initial Inspection and Diagnostic Overview) for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions (Initial Inspection and Diagnostic Overview) provides an overview of each diagnostic category.
DTC Descriptors
DTC B0158 03
- Outside Air Temperature Sensor Circuit Voltage Below Threshold
DTC B0158 06
- Outside Air Temperature Sensor Circuit Short to Ground or Open
DTC B0158 07
- Outside Air Temperature Sensor Circuit Voltage Above Threshold
Diagnostic Fault Information
Circuit/System Description
The HVAC control module supplies the ambient air temperature sensor with a low reference circuit and 5-volt signal circuit. The HVAC control module 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
Ignition ON.
Conditions for Setting the DTC
The HVAC control module detects the ambient air temperature sensor signal circuit is less than -36°C (-38°F) or greater than 215°C (419°F) for more than 15 seconds.
Action Taken When the DTC Sets
* The HVAC control module will display dashes for outside air temperature.
* 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 HVAC control module no longer detects the condition that set the DTC.
* The history DTC will clear after 100 fault-free ignition cycles.
Diagnostic Aids
If the ambient air temperature sensor has an out of range condition caused by a short to voltage, short to ground, or open/high resistance the scan tool will display the last normal operating range.
Reference Information
Schematic Reference
HVAC Schematics (HVAC - Automatic)
Connector End View Reference
Component Connector End Views (Connector Views)
Description and Operation
* Air Delivery Description and Operation (Air Delivery Description and Operation)
* Air Temperature Description and Operation (Air Temperature Description and Operation)
Electrical Information Reference
* Circuit Testing (Component Tests and General Diagnostics)
* Connector Repairs (Component Tests and General Diagnostics)
* Testing for Intermittent Conditions and Poor Connections (Component Tests and General Diagnostics)
* Wiring Repairs (Component Tests and General Diagnostics)
Scan Tool Reference
Control Module References (Programming and Relearning) for scan tool information
Circuit/System Testing
1. Ignition OFF, disconnect the harness connector at the ambient air temperature sensor.
2. Ignition OFF, test for less than 1 ohm between the low reference circuit terminal B and ground.
• If greater than the specified range, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the HVAC control module.
3. Ignition ON, test for 5 volts between the signal circuit terminal A and the low reference circuit terminal B.
• If greater than the specified range, test the signal circuit for a short to voltage. If the circuit tests normal, replace the HVAC control module.
• If less than the specified range, test the signal circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the HVAC control module.
4. If all circuits test normal, test or replace the ambient air temperature sensor.
Repair Instructions
Perform the Diagnostic Repair Verification (Verification Tests) after completing the diagnostic procedure.
* Ambient Air Temperature Sensor Replacement (Service and Repair)
* Control Module References (Programming and Relearning) for HVAC control module replacement, setup, and programming