• | 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 |
---|---|---|---|---|
Left Sunload Sensor Signal | B0183 06 | B0183 06 | B0183 06 | -- |
Right Sunload Sensor Signal | B0188 06 | B0188 06 | B0188 06 | -- |
Low Reference | -- | B0183 06, B0188 06 | B0183 06, B0188 06 | -- |
The vehicle uses left and right sunload sensors that are integrated into one sensor assembly along with the ambient light sensor. Low reference and signal circuits enable the sensor to operate. 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. |
Ignition ON.
The HVAC control module detects the signal circuit is less than 5 counts or greater than 250 counts.
• | The driver information center (DIC) will display SERVICE A/C SYSTEM. |
• | If the DTC is set the system will act as if no sunload condition exists. |
• | 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. |
Automatic HVAC Description and Operation
Control Module References for scan tool information
Ignition ON, observe the appropriate scan tool Sunload Sensor parameter. The reading should be between 5 and 250 counts and change with sunlight changes.
⇒ | 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. |
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
• | Control Module References for HVAC control module replacement, setup, and programming |