Spark

Air Temperature Malfunction

Air Temperature Sensors

The inside air temperature sensor is a part of the HVAC control and the ambient air temperature sensor is a 2-wire negative temperature co-efficient thermistor. The vehicle uses the following air temperature sensors:

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 signal varies between 0-5 V.

Sun Load Temperature Sensor

The sun load temperature sensor is a 2-wire photo diode. Low reference and signal circuits enable the sensors to operate. As the sunload increases, the sensor signal decreases. The sensor signal varies between 0-5 V. The sunload sensor provides the HVAC control with a measurement of the amount of light shining on the vehicle.

Schematic Reference

HVAC Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

Automatic HVAC Description and Operation

Electrical Information Reference

Ambient Air Temperature Sensor Circuit Malfunction

1. Ignition OFF, disconnect the harness connector at the B9 Ambient Air Temperature Sensor.
2. Test for less than 10 Ω between the low reference circuit terminal B and ground.

⇒	If greater than the specified range, test the low reference circuit for an open/high resistance.

3. Ignition ON, test for 4.8-5.2 V between the signal circuit terminal A and the low reference circuit terminal B.

⇒	If less than the specified range, test the signal circuit for a short to ground or open/high resistance. If the circuit tests normal, replace the K33 HVAC Control.

⇒	If greater than the specified range, test the signal circuit for a short to voltage. If the circuit tests normal, replace the K33 HVAC Control.

4. If all circuits test normal, replace the B9 Ambient Air Temperature Sensor.

Sun Load Temperature Sensor Circuit Malfunction

1. Ignition OFF, disconnect the harness connector at the B104 Sun Load Temperature Sensor.
2. Test for less than 10 Ω between the low reference circuit terminal 1 and ground.

⇒	If greater than the specified range, test the low reference circuit for an open/high resistance.

3. Ignition ON, test for 4.8--5.2 V between the signal circuit terminal 3 and the low reference circuit terminal 1.

⇒	If less than the specified range, test the signal circuit for a short to ground or open/high resistance. If the circuit tests normal, replace the K33 HVAC Control.

⇒	If greater than the specified range, test the signal circuit for a short to voltage. If the circuit tests normal, replace the K33 HVAC Control.

4. If all circuits test normal, replace the B104 Sun Load Temperature Sensor.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.