B0188

DTC B0183 or B0188

Diagnostic Instructions

* Perform the Diagnostic System Check - Vehicle (Initial Inspection and Diagnostic Overview) prior to using this diagnostic procedure.
* ReviewStrategy 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/System 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 very 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 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.

Conditions for Running the DTC

Ignition 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

* The HVAC control module will display dashes for outside air temperature.
* 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.

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 100 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

Air Temperature Description and Operation (Air Temperature Description and Operation)
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 Testing

1. Ignition OFF, disconnect the harness connector at the sunload sensor.
2. Test for less than 1.0 ohm between the ground circuit terminal C and ground.

• If greater than the specified range, test the ground circuit for an open/high resistance.

3. Ignition ON, verify the appropriate scan tool Sunload Sensor parameter is greater than 250 counts.

• If not the specified value, test the appropriate signal circuit terminal listed below for a short to ground. If the circuit tests normal, replace the HVAC control module.

* Left sunload sensor circuit terminal A
* Right sunload sensor circuit terminal B

4. Install a 3A fused jumper wire between the ground circuit terminal C and the signal circuit terminal of the appropriate sensor listed below. Verify the appropriate scan tool Sunload Sensor parameter is less than 5 counts.

* Left sunload sensor circuit terminal A
* Right sunload sensor circuit terminal B

• If not the specified value, 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 Sensor Replacement (Service and Repair)
* Control Module References (Programming and Relearning) for HVAC control module replacement, setup, and programming