B0183
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 02
- Solar Load Sensor 1 Circuit Short to Ground
DTC B0183 05
- Solar Load Sensor 1 Circuit Short to Battery or Open
DTC B0188 02
- Solar Load Sensor 2 Circuit Short to Ground
DTC B0188 05
- Solar Load Sensor 2 Circuit Short to Battery or Open
Diagnostic Fault Information
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 driver sunload sensor.
* B0188 is for the passenger sunload sensor.
Conditions for Running the DTC
Ignition 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 100 fault-free ignition cycles have occurred.
Reference Information
Schematic Reference
HVAC Schematics HVAC - Automatic
Connector End View Reference
Component Connector End Views 1-2 Shift Solenoid (SS) Valve (M30)
Description and Operation
* Air Temperature Description and Operation Air Temperature
* Air Delivery Description and Operation Air Delivery
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 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 sunload 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.
1. Ignition OFF and all vehicle systems OFF, disconnect the harness connector at the ambient light/sunload sensor. It may take up to 2 minutes for all vehicle systems to power down.
2. Test for less than 10 ohms between the ground circuit terminal C and ground.
• If 10 ohms or greater
1. Ignition OFF, disconnect the X1 harness connector at the HVAC control module.
2. Test for less than 2 ohms in the ground circuit end to end.
• If 2 ohms or greater, repair the open/high resistance in the circuit.
• If less than 2 ohms, repair the open/high resistance in the ground connection.
• If less than 10 ohms
3. Ignition ON.
4. Test for 4.8-5.2 V between the ground circuit terminal C and the signal circuit terminals listed below:
* Driver sunload sensor signal terminal A.
* Passenger sunload sensor signal terminal B.
• If less than 4.8 V
1. Ignition OFF, disconnect the appropriate X1 harness connector at the HVAC control module.
2. Test for infinite resistance between the signal circuit and ground.
• If less than infinite resistance, repair the short to ground on the circuit.
• If infinite resistance
3. Test for less than 2 ohms in the signal circuit end to end.
• If 2 ohms or greater, repair the open/high resistance in the circuit.
• If less than 2 ohms, replace the HVAC control module.
• If greater than 5.2 V
1. Ignition OFF, disconnect the appropriate X1 harness connector at the HVAC control module.
2. Test for less than 1 V between the signal circuit and ground.
• If 1 V or greater, repair the short to voltage on the circuit.
• If less than 1 V, replace the HVAC control module.
• If between 4.8-5.2 V
5. Test or replace the ambient light/sunload sensor.
6. Verify the DTC does not set when operating the vehicle under the Conditions for Running the DTC.
• If the DTC sets
Replace the HVAC control module.
• If the DTC does not set
7. All OK.
Repair Instructions
Perform the Diagnostic Repair Verification Verification Tests after completing the repair.
* Sun Load Temperature Sensor Replacement Service and Repair
* Control Module References Control Module References for HVAC control module replacement, programming and setup