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 B0183: Solar Load Sensor 1 CircuitDTC B0188: Solar Load Sensor 2 Circuit
Diagnostic Fault Information
Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance |
|---|---|---|---|---|
Left Sunload Sensor Signal | B0183 | B0183 | B0183 | -- |
Right Sunload Sensor Signal | B0188 | B0188 | B0188 | -- |
Sunload sensors Ground | -- | B0183 , B0188 | B0183 , B0188 | -- |
Circuit Description
The sunload sensor is a 2-wire photo diode. The vehicle uses left and right sunload sensors. The two sensors are integrated into the sunload sensor assembly along with the ambient light sensor. Ground and signal circuits enable the sensors to operate. As the sunload increases, the sensor signal decreases. The sensor signal varies between 0 and 5 volts. The HVAC control module converts the signal to a range between 0 and 255 counts. The sunload sensor provides the HVAC control module with a measurement of the amount of light shining on the vehicle. Bright or high intensity light causes the vehicles interior temperature to increase. The HVAC system compensates for the increased temperature by diverting additional cool air into the vehicle.
The following DTCs are for the left and right sunload sensors.
| • | B0183 is for the left sunload sensor. |
| • | B0188 is for the right sunload sensor. |
Conditions for Running the DTC
The ignition is ON.
Conditions for Setting the DTC
The HVAC control module detects the signal circuit is less than 5 counts or greater than 250 counts.
Action Taken When the DTC Sets
| • | The driver information center (DIC) will display SERVICE A/C SYSTEM. |
| • | The system will operate as if no sunload condition exists. |
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 50 fault-free ignition cycles. |
Reference Information
Schematic Reference
Connector End View Reference
Description and Operation
Electrical Information Reference
Scan Tool Reference
Control Module References for scan tool information
Circuit/System Verification
Ignition ON, observe the appropriate scan tool Sunload Sensor parameter. The reading should be between 5 and 250 counts and change with sunlight intensity.
Circuit/System Testing
Important: If a solar load sensor has an out of range condition caused by a short to voltage, short to ground, or an open/high resistance, the scan tool will display the same value: 225 counts.
- Ignition OFF, disconnect the harness connector at the sunload sensor.
- Test for less than 10 ohms between the ground circuit terminal C and ground.
- Ignition ON, test for 4.8-5.2 volts between the ground circuit terminal C and the appropriate signal circuit terminal .
- If all circuits test normal, test or replace the sunload sensor.
| ⇒ | If greater than the specified range, test the ground circuit for an open/high resistance. |
| • | 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. |
Repair Instructions
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
| • | Control Module References for HVAC control module replacement, setup, and programming |
