Circuit Description
The HVAC control assembly determines the outside air temperature through an input from the ambient air temperature sensor. The HVAC control assembly receives a voltage signal from the ambient air temperature sensor through circuit 735. The ambient air temperature sensor is grounded by the HVAC control assembly through circuit 61.
The internal resistance of the ambient air temperature sensor decreases as temperature increases. The HVAC control assembly uses the signal from the ambient air temperature sensor to display the outside air temperature on the HVAC control assembly display.
Conditions for Setting the DTC
The HVAC control assembly performs a check on the operation of the ambient air temperature sensor and detects a short to ground in circuit 735.
Action Taken When the DTC Sets
| • | The HVAC control assembly stores DTC B0332 in memory. |
| • | The HVAC control assembly uses 9°C (49°F) as a substitute for the ambient air temperature reading , allowing the A/C system to continue operation. |
Conditions for Clearing the DTC
| • | A short to ground in circuit 735 is no longer present. |
| • | Under all fault conditions, the ignition switch must be cycled from on to off, back to on before this DTC can change from current to history. |
| • | A history DTC clears after 100 drive cycles if a short to ground in circuit 735 is no longer present. |
| • | Using a scan tool. |
Diagnostic Aids
The following conditions may cause this DTC to set:
| • | A short to ground in circuit 735. |
| • | A voltage spike in circuit 735. |
| • | A faulty ambient air temperature sensor. |
| • | A faulty HVAC control assembly. |
Test Description
The number(s) below refer to the step number(s) on the diagnostic table.
-
This step checks for proper voltage value at the ambient air temperature sensor.
-
This step checks for a short to ground in 735.
Step | Action | Value(s) | Yes | No |
|---|---|---|---|---|
1 | Was the HVAC functional check performed? | -- | Go to Step 2 | Go to Functional Check |
Is the measured voltage within the specified value? | 4.5-5.5V | Go to Step 3 | Go to Step 4 | |
3 | Check the ambient air temperature sensor connector for proper terminal contact. If connection is OK, then replace the ambient air temperature sensor. Refer to Ambient Temperature Sensor Replacement . Is the repair complete? | -- | Go to Functional Check | -- |
Is the measured resistance same as the specified value? | ∞ | Go to Step 6 | Go to Step 5 | |
5 | Repair a short to ground in circuit 735. Is the repair complete? | -- | Go to Functional Check | -- |
6 | Replace the HVAC control assembly. Refer to Control Assembly Replacement . Is the repair complete? | -- | Go to Functional Check | -- |
