Diagnostic Instructions

DTC Descriptors

DTC B0163 03: Passenger Compartment Temperature Sensor Circuit Below Threshold

DTC B0163 06: Passenger Compartment Temperature Sensor Circuit Short to Ground or Open

DTC B0163 07: Passenger Compartment Temperature Sensor Circuit Above Threshold

DTC B3933: Evaporator Temperature Sensor Circuit

Diagnostic Fault Information

Circuit	Short to Ground	Open/High Resistance	Short to Voltage	Signal Performance
Ambient Air Temperature Sensor Signal	B0158 06	B0158 06	B0158 07*	B0158 03, 07
Inside Air Temperature Sensor Signal	B0163 06	B0163 06	B0163 07*	B0163 03, 07
Left Sunload Sensor Signal	B0183	B0183	B0183*	--
Right Sunload Sensor Signal	B0188	B0188	B0188*	--
Evaporator Temperature Sensor Signal	B3933 06	B3933 06	B3933 06*	--
Low Reference	--	B3933 06, B0158 06, B0163 06	B3933 06, B0158 07, B0163 07	B0158 07, B0163 07
Sunload sensors Ground Circuit	--	B0183, B0188	B0183, B0188	--
* If the signal circuit is shorted to voltage B0158, B0163, B0183, B0188 and B3933 will all set.

Circuit/System Description

The HVAC control module supplies the evaporator temperature and inside air temperature sensors with a low reference circuit and 5-volt signal circuit. The HVAC control module determines the voltage drop across the sensors, which is proportional to temperature. As the air temperature increases, the sensor resistance decreases and the voltage signal decreases. As the air temperature decreases, the sensor resistance increases and the voltage signal increases. The inside air temperature sensor assembly has an internal fan that draws air across the sensor and is controlled by the HVAC control module. The internal fan motor is connected to body ground.

Conditions for Running the DTC

The ignition is turned ON.

Conditions for Setting the DTC

B0163

The HVAC control module detects the inside air temperature sensor signal circuit is less than -36°C (-38°F) or more than 215°C (419°F) for more than 15 seconds.

B3933

The HVAC control module detects the evaporator temperature sensor signal circuit is less than -36°C (-38°F) or more than 215°C (419°F) for more than 15 seconds.

Action Taken When the DTC Sets

B0163

B3933

Conditions for Clearing the DTC

Reference Information

Schematic Reference

HVAC Schematics

Connector End View Reference

HVAC Connector End Views

Description and Operation

Air Temperature Description and Operation

Electrical Information Reference

Scan Tool Reference

Circuit/System Testing

1. Ignition OFF, disconnect the harness connector at the appropriate temp sensor.
2. Ignition OFF, test for less than 1 ohm of resistance between the ground circuit and the low reference circuit terminal of the appropriate sensor listed below.

•	DTC B0163 passenger compartment temperature sensor circuit terminal D.

•	DTC B3933 evaporator temperature sensor circuit terminal B.

⇒	If greater than the specified range, test the low reference circuit terminal for an open/high resistance. If the circuit tests normal, replace the HVAC control module.

3. Ignition ON, verify the appropriate sensor parameter is greater than 215°C (419°F).

⇒	If less than the specified range, test the signal circuit terminal A for a short to ground. If the circuit tests normal, replace the HVAC control module.

4. Install a 3A fused jumper wire between the signal circuit terminal A and the low reference circuit terminal of the appropriate sensor listed below. Verify the appropriate temperature sensor parameter is less than -36°C (-38°F).

•	DTC B0163 passenger compartment temperature sensor circuit terminal D.

•	DTC B3933 evaporator temperature sensor circuit terminal B.

⇒	If greater than the specified range, test the signal circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the HVAC control module.

5. If all circuits test normal, test or replace the appropriate temperature sensor.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.