B0189
DTC B0184 or B0189
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 B0184
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Solar Load Sensor 1 Circuit Range/Performance (left)
DTC B0189
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Solar Load Sensor 2 Circuit Range/Performance (right)
Diagnostic Fault Information
Circuit/System 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. 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 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 a measurement of the amount of light shining on the vehicle. Bright or high intensity light causes the vehicles inside temperature to increase. The HVAC system compensates for the increased temperature by diverting additional cool air into the passenger compartment when in the Auto mode.
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 0.09 volt (5 counts) or more than 4.90 volts (250 counts).
Action Taken When the DTC Sets
If the DTC sets due to a low voltage condition, the HVAC control module will operate the system as if a maximum sunload condition exists. If the DTC sets due to a high voltage condition, the HVAC control module will operate the system as if a minimum 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 Electrical Diagrams
Connector End View Reference
Component Connector End Views 5 Bow Lowered Switch (CM7)
Description and Operation
Automatic HVAC Description and Operation Description and Operation
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 assembly.
2. Test for less than 2.0 ohm 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 Left Sunload Sensor parameter is greater than 250 counts.
• If not the specified value, test the signal circuit terminal A for a short to ground. If the circuit tests normal, replace the HVAC control module.
4. Ignition ON, verify the Right Sunload Sensor parameter is greater than 250 counts.
• If not the specified value, test the signal circuit terminal B for a short to ground. If the circuit tests normal, replace the HVAC control module.
5. Install a 3A fused jumper wire between the signal circuit terminal A and the low reference circuit terminal C. Verify the Left Sunload Sensor parameter is less than 5 counts.
• 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.
6. Install a 3A fused jumper wire between the signal circuit terminal B and the low reference circuit terminal C. Verify the Right Sunload Sensor parameter is less than 5 counts.
• 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.
7. If all circuits test normal, test or replace the sunload sensor assembly.
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 Control Module References for HVAC control module replacement, setup, and programming