B0188
DTC B0183 or B0188
Diagnostic Instructions
* Perform the Diagnostic System Check - Vehicle Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis Strategy Based Diagnosis for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions Diagnostic Procedure Instructions provides an overview of each diagnostic category
DTC Descriptors
DTC B0183 03
- Left Solar Load Sensor 1 Circuit Voltage Below Threshold
DTC B0183 07
- Left Solar Load Sensor 1 Circuit Voltage Above Threshold
DTC B0188 03
- Right Solar Load Sensor 2 Circuit Voltage Below Threshold
DTC B0188 07
- Right Solar Load Sensor 2 Circuit Voltage Above Threshold
Diagnostic Fault Information
Circuit Description
The sunload sensor is a 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 3906.6 W/m2. 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.
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 0 W/m2 or greater than 3900 W/m2.
Action Taken When the DTC Sets
If the DTC is set the system will act as if no sunload condition exists.
Conditions for Clearing the DTC
* The condition for setting the DTC is no longer present.
* The history DTC will clear after 50 fault-free ignition cycles.
* The DTC can be cleared using a scan tool.
Reference Information
Schematic Reference
HVAC Schematics Electrical Diagrams
Connector End View Reference
Component Connector End Views Fuel Pump and Level Sensor Assembly
Electrical Information Reference
* Circuit Testing Circuit Testing
* Connector Repairs Connector Repairs
* Testing for Intermittent Conditions and Poor Connections Testing for Intermittent Conditions and Poor Connections
* Wiring Repairs Wiring Repairs
Scan Tool Reference
Control Module References Control Module References for scan tool information
Circuit/System Testing
1. Ignition OFF, disconnect the harness connector at the sunload sensor.
2. Ignition OFF, test for less than 10 ohms between the low reference circuit terminal C and ground.
• If greater than the specified range, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the HVAC control module.
3. Ignition ON, verify the scan tool Sun Load Sensor parameter is greater than 3900.0 W/m2.
• If less than the specified range, test the signal circuit terminal listed below for a short to ground. If the circuit tests normal, replace the HVAC control module.
* Left solar load sensor circuit terminal A.
* Right solar load sensor circuit terminal B.
4. Install a 3A fused jumper wire between the signal circuit terminal A or B and the low reference circuit terminal C. Verify the scan tool Sun Load Sensor Parameter is less than 1 W/m2.
• If greater than the specified range, test the signal circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the HVAC control module.
5. If all circuits test normal, test or replace the sunload sensor.
Repair Instructions
Perform the Diagnostic Repair Verification Verification Tests after completing the diagnostic procedure.
* Sunload and Twilight Sentinel Sensor Replacement Service and Repair
* Control Module References Control Module References for HVAC control module replacement, setup, and programming