Diagnostic Instructions
| • | Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. |
| • | Review Strategy Based Diagnosis for an overview of the diagnostic approach. |
| • | Diagnostic Procedure Instructions provides an overview of each diagnostic category. |
DTC Descriptors
DTC B0163 06: Passenger Compartment Temperature Sensor Circuit Short to Ground or OpenDTC B3933 06: Evaporator Temperature Sensor Circuit Short to Ground or Open
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, B0158 07 |
Inside Air Temperature Sensor Signal | B0163 06 | B0163 06 | B0163 06* | 1 |
Left Sunload Sensor Signal | B0183 06 | B0183 06 | B0183 06* | 1 |
Right Sunload Sensor Signal | B0188 06 | B0188 06 | B0188 06* | 1 |
Evaporator Temperature Sensor Signal | B3933 06 | B3933 06 | B3933 06* | 1 |
Low Reference | -- | B3933 06, B0158 06, B0163 06 | B3933 06, B0158 07, B0163 06 | B0158 07 |
Sunload Sensors Ground | -- | B0183 06, B0188 06 | B0183 06, B0188 06 | -- |
*If the signal circuit is shorted to voltage B0158, B0163, B0183, B0188 and B3933 will all set. 1. Air Temperature Malfunction | ||||
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. As the air temperature decreases, the sensor resistance 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
Ignition 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 greater 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 greater than 215°C (419°F) for more than 15 seconds.
Action Taken When the DTC Sets
B0163
| • | The system operates using a default value. |
| • | The HVAC control module will display dashes for outside air temperature. |
| • | The DIC will display SERVICE A/C SYSTEM. |
B3933
| • | The A/C compressor is disabled. |
| • | The DIC will display SERVICE A/C SYSTEM. |
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. |
Reference Information
Schematic Reference
Connector End View Reference
Description and Operation
Air Temperature Description and Operation
Electrical Information Reference
Scan Tool Reference
Control Module References for scan tool information
Circuit/System Testing
- Ignition OFF, disconnect the harness connector at the appropriate temperature sensor.
- Ignition OFF, test for less than 1 ohm between the low reference circuit terminal listed below and ground.
- Ignition ON, verify the appropriate scan tool Temperature Sensor parameter is greater than 215°C (419°F).
- Install a 3A fused jumper wire between the signal circuit terminal A and the low reference circuit terminal listed below. Verify the appropriate scan tool Temperature Sensor parameter is less than -36°C (-38°F).
- If all circuits test normal, test or replace the temperature sensor.
| • | Passenger compartment temperature sensor circuit terminal D |
| • | Evaporator temperature sensor circuit terminal B |
| ⇒ | 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. |
| ⇒ | If less than the specified range, test the signal circuit for a short to ground. If the circuit tests normal, replace the HVAC control module. |
| • | Passenger compartment temperature sensor circuit terminal D |
| • | 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. |
Repair Instructions
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
| • | Control Module References for HVAC control module replacement, setup, and programming |
