Circuit Description
The sunload sensor is a 2-wire photo diode. The vehicle uses left and right sunload sensors. The 2 sensors are integrated into the sunload sensor assembly along with the ambient light sensor. Low reference and signal circuits enable the sensor to operate.
As the sunload increases, the sensor signal decreases. The sensor operates within an intensity range between completely dark and bright. The sensor signal varies between 0-5 volts. The HVAC control module converts the signal to a range between 0-255 counts.
The sunload sensor provides the HVAC control module a measurement of the amount of light shining on the vehicle. Bright, or high intensity, light causes the vehicles inside temperature to increase. The HVAC system compensates for the increased temperature by
diverting additional cool air into the vehicle.
| • | Solar Load Sensor 1 Circuit refers to the left sunload sensor |
| • | Solar Load Sensor 2 Circuit refers to the right sunload sensor |
DTC Descriptors
This diagnostic procedure supports the following DTCs:
| • | DTC B0183 Solar Load Sensor 1 Circuit |
| • | DTC B0188 Solar Load Sensor 2 Circuit |
This vehicle has DTCs which include DTC Symptoms. For more information on DTC Symptoms, refer to
DTC Symptom Description
.
DTC Symptom
| DTC Symptom Descriptor
|
00
| Out of Range Condition
|
Conditions for Running the DTC
The ignition is turned ON.
Conditions for Setting the DTC
The HVAC control module detects the signal circuit is less than 0.09 volt (5 counts) or more than 4.90 volts (250 counts).
Action Taken When the DTC Sets
| • | If the DTC is set the system will act as if no sunload condition exists. |
| • | The driver information center (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 a failure. |
| • | The history DTC will clear after 50 fault-free ignition cycles. |
| • | The DTC can be cleared with a scan tool. |
Reference Information
Schematic Reference
HVAC Schematics
Connector End View Reference
HVAC Connector End Views
Electrical Information Reference
Scan Tool Reference
Circuit/System Testing
- Ignition OFF, disconnect the harness connector at the sunload sensor.
- Test for less than 10 ohms between the ground circuit terminal C and ground.
| ⇒ | If greater than the specified range, test the ground circuit for an open/high resistance. |
- Ignition ON, test for 4.8-5.2 volts between the ground circuit terminal C and the appropriate signal circuit terminal listed below:
| • | Left solar load sensor circuit terminal A. |
| • | Right solar load sensor 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 HVAC control module. |
| ⇒ | If greater than the specified range, test the signal circuit for a short to voltage. If the circuit tests normal, replace the HVAC control module. |
- If all circuits test normal, test or replace the sunload sensor.
Repair Instructions
Perform the
Diagnostic Repair Verification
after completing the diagnostic procedure.
