• | 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. |
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 a signal circuit is shorted to voltage B0158, B0163, B0183, B0188 and B3933 will all set. |
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 and the voltage signal decreases. As the air temperature decreases, the sensor resistance increases and the voltage signal increases.
The ignition is turned ON.
The HVAC control module detects the ambient air temperature sensor signal circuit is less than -36°C (-38°F) or more than 215°C (419°F) for more than 15 seconds.
• | 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. |
• | 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 50 fault-free ignition cycles. |
Air Temperature Description and Operation
⇒ | 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 not the specified voltage, test the signal circuit for a short to voltage, short to ground or open/high resistance. If the circuit tests normal, replace the HVAC control module. |
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
• | Control Module References for HVAC control module replacement, setup and programming |