B0188

DTC B0183 or B0188

Diagnostic Instructions

* Perform the Diagnostic System Check - Vehicle (Initial Inspection and Diagnostic Overview) prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis (Initial Inspection and Diagnostic Overview) for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions (Initial Inspection and Diagnostic Overview) provides an overview of each diagnostic category.



DTC Descriptors
DTC B0183 06
- Solar Load Sensor 1 Circuit Short to Ground or Open

DTC B0188 06
- Solar Load Sensor 2 Circuit Short to Ground or Open




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/m(2). 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

Ignition ON.


Conditions for Setting the DTC

The HVAC control module detects the signal circuit is less than 0 W/m(2) or greater than 3900 W/m(2).


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

HVAC Schematics (HVAC - Automatic)
Connector End View Reference

Component Connector End Views (Connector Views)
Description and Operation

Component Connector End Views (Connector Views)
Electrical Information Reference

* Circuit Testing (Component Tests and General Diagnostics)
* Connector Repairs (Component Tests and General Diagnostics)
* Testing for Intermittent Conditions and Poor Connections (Component Tests and General Diagnostics)
* Wiring Repairs (Component Tests and General Diagnostics)

Scan Tool Reference

Control Module References (Programming and Relearning) for scan tool information


Circuit/System Verification

Ignition ON, observe the appropriate scan tool Sunload Sensor parameter. The reading should be between 0 and 3906.6 W/m(2) and change with sunlight intensity.


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/m(2) .

• 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/m(2).

• 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.

* Sun Load Temperature Sensor Replacement (Service and Repair)
* Control Module References (Programming and Relearning) for HVAC control module replacement, setup, and programming