Displays and Gages
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 provide an overview of each diagnostic category.
DTC Descriptors
DTC B0158 02
- Outside Air Temperature (OAT) Sensor Short to Ground
DTC B0158 05
- Outside Air Temperature (OAT) Sensor Short to Battery or Open
Diagnostic Fault Information
Circuit/System Description
The ambient air temperature sensor is a variable resistor interfaced to the body control module (BCM). The BCM monitors the ambient air temperature sensor. The ambient air temperature sensor is a 2-wire negative temperature co-efficient thermistor. The BCM applies 5 volts to an internal input resistor connected to the signal circuit of the ambient air temperature sensor. The BCM also provides the low reference circuit to the ambient air temperature sensor. When the ambient air temperature is cold, the sensor resistance is high and the signal voltage is high. When the ambient air temperature is hot, the sensor resistance is low and the signal voltage is low. The BCM provides the logic for reading the ambient air temperature sensor, filtering the data and transmitting the information via the serial data circuit to the driver information center (DIC) for display in the radio or IPC. The temperature is sent to the DIC in Degrees Celsius. The IPC/radio is responsible for displaying the temperature and converting to Degrees Fahrenheit. Two serial data signals are ultimately generated; an un-filtered value and a filtered value for use by the DIC display. The BCM also provides the sensor out-of-range detection and compensates for engine temperature by utilizing vehicle speed and engine off time duration.
Conditions for Running the DTC
* The ignition is in ACC or RUN.
* The system voltage is between 9-16 volts.
Conditions for Setting the DTC
The BCM detects that the ambient air temperature is 0.4 volt or more than 4.8 volts.
Action Taken When the DTC Sets
* The default value of 3°C (38°F) will be substituted for the ambient air temperature sensor data by the BCM.
* The driver information center (DIC) will display SET TEMPERATURE when ON.
Conditions for Clearing the DTC
* The DTC becomes history when the BCM no longer detects a failure.
* The history DTC clears after 40 malfunction-free ignition cycles.
Reference Information
Schematic Reference
* Driver Information System Schematics Driver Information System Schematics
* HVAC Schematics HVAC - Manual
Connector End View Reference
Component Connector End Views Connector End Views By Name
Description and Operation
* Air Temperature Description and Operation Air Temperature
* Driver Information Center (DIC) Description and Operation (Radio) Driver Information Center (DIC) (Radio)Driver Information Center (DIC) Description and Operation (IPC) Driver Information Center (DIC) (IPC)
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. 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 value, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the BCM.
3. Ignition ON, verify the scan tool Ambient Air Temperature Sensor parameter is greater than 4.7 volts.
• If less than the specified value, test the signal circuit terminal A for a short to ground. If the circuit tests normal, replace the BCM.
4. Install a 3-A fused jumper wire between the ambient air temperature sensor signal circuit terminal A and the low reference circuit terminal B. Verify the scan tool Ambient Air Temperature Sensor parameter is less than 0.4 volt.
• If greater than the specified value, test the signal circuit for an open/high resistance. If the circuit tests normal replace the BCM.
5. 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 Gauge Sensor Replacement Service and Repair
* Control Module References Programming and Relearning for BCM replacement, setup, and programming