B0514
DTC B0158, B0163, B0173, B0178, B0509, or B0514
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 05
- Outside Air Temperature Sensor Circuit Short to Battery or Open
DTC B0158 02
- Outside Air Temperature Sensor Circuit Short to Ground
DTC B0163 05
- Passenger Compartment Temp Sensor 1 Circuit Short to Battery or Open
DTC B0163 02
- Passenger Compartment Temp Sensor 1 Circuit Short to Ground
DTC B0173 05
- Output Air Temperature Sensor 1 Circuit Short to Battery or Open
DTC B0173 02
- Output Air Temperature Sensor 1 Circuit Short to Ground
DTC B0178 05
- Output Air Temperature Sensor 2 Circuit Short to Battery or Open
DTC B0178 02
- Output Air Temperature Sensor 2 Circuit Short to Ground
DTC B0509 05
- Output Air Temperature Sensor 3 Circuit Short to Battery or Open
DTC B0509 02
- Output Air Temperature Sensor 3 Circuit Short to Ground
DTC B0514 05
- Output Air Temperature Sensor 4 Circuit Short to Battery or Open
DTC B0514 02
- Output Air Temperature Sensor 4 Circuit Short to Ground
Diagnostic Fault Information
Circuit/System Description
Air Temperature Sensors
The air temperature sensors are a 2-wire negative temperature co-efficient thermistor. The vehicle uses the following air temperature sensors:
* Ambient Air Temperature Sensor
* Inside Air Temperature Sensor Assembly
* Upper Left Air Temperature Sensor
* Upper Right Air Temperature Sensor
* Lower Left Air Temperature Sensor
* Lower Right Air Temperature Sensor
A signal and low reference circuit enables the sensor to operate. As the air temperature surrounding the sensor increases, the sensor resistance decreases. The sensor signal voltage decreases as the resistance decreases. The sensor operates within a temperature range between -40 to +101°C (-40 to +215°F). The sensor signal varies between 0-5 volts. The HVAC control module converts the signal to a range between 0-255 counts. As the air temperature increases the count value will decrease. If the HVAC control module or auxiliary HVAC control module detects a malfunctioning sensor, then the control module software will use a defaulted air temperature value. The default value for the duct air temperature sensors will be displayed on the scan tool. The default value for the ambient and inside air temperature sensors will not be displayed on the scan tool. The scan tool parameter for the ambient and inside air temperature sensors are the actual state of the signal circuit. The default action ensures that the HVAC system can adjust the inside air temperature near the desired temperature until the condition is corrected.
Diagnostic Aids
Conditions for Running the DTC
Ignition ON.
Conditions for Setting the DTC
The HVAC control module detects the temperature sensor signal circuit is less than -35°C (-39°F) or greater than 85°C (185°F) for greater than 15 seconds.
Action Taken When the DTC Sets
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 have occurred.
Reference Information
Schematic Reference
HVAC Schematics HVAC - Automatic
Connector End View Reference
Component Connector End Views 1-2 Shift Solenoid (SS) Valve (M30)
Description and Operation
* Air Temperature Description and Operation Air Temperature
* Air Delivery Description and Operation Air Delivery
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 Testing
1. Ignition OFF, all vehicle systems OFF, and the scan tool disconnected, disconnect the harness connector at the appropriate temperature 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 listed below and ground:
* Ambient air temperature sensor terminal B
* Inside air temperature sensor terminal D
* Left upper air temperature sensor terminal A
* Right upper air temperature sensor terminal A
* Left lower air temperature sensor terminal A
* Right lower air temperature sensor terminal A
• 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 listed below and ground:
* Ambient air temperature sensor terminal A
* Inside air temperature sensor terminal A
* Left upper air temperature sensor terminal B
* Right upper air temperature sensor terminal B
* Left lower air temperature sensor terminal B
* Right lower air temperature sensor terminal B
• If less than 4.8 V
1. Ignition OFF, disconnect the appropriate X1, X2, or X3 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 appropriate X1, X2, or X3 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
5. Replace the 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 appropriate temperature sensor.
2. Test for the appropriate resistance value between the signal and the low reference terminals. Refer to Sensor Resistance Table Electrical Specifications for resistance values.
• If not within 10 % of the specified value
Replace the temperature sensor.
• If within 10 % of the specified value
3. All OK.
Repair Instructions
Perform the Diagnostic Repair Verification Verification Tests after completing the repair.
* Duct Air Temperature Sensor Replacement - Upper Right Side Duct Air Temperature Sensor Replacement - Upper Right Side
* Duct Air Temperature Sensor Replacement - Upper Left Side Duct Air Temperature Sensor Replacement - Upper Left Side
* Duct Air Temperature Sensor Replacement - Lower Left Side Duct Air Temperature Sensor Replacement - Lower Left Side
* Duct Air Temperature Sensor Replacement - Lower Right Side Duct Air Temperature Sensor Replacement - Lower Right Side
* Ambient Air Temperature Sensor Replacement Service and Repair
* Inside Air Temperature Sensor Replacement Service and Repair
* Control Module References Control Module References for HVAC control module replacement, programming and setup