Diagnostic Instructions
| • | Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. |
| • | Review Strategy Based Diagnosis for an overview of the diagnostic approach. |
| • | Diagnostic Procedure Instructions provides an overview of each diagnostic category. |
DTC Descriptors
DTC B0183: Solar Load Sensor 1 CircuitDTC B0188: Solar Load Sensor 2 Circuit
Diagnostic Fault Information
Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance |
|---|---|---|---|---|
Ambient Air Temperature Sensor Signal | B0158 06 | B0158 06 | B0158 07* | B0158 03, 07 |
Inside Air Temperature Sensor Signal | B0163 06 | B0163 06 | B0163 07* | B0163 03, 07 |
Left Sunload Sensor Signal | B0183 | B0183 | B0183* | -- |
Right Sunload Sensor Signal | B0188 | B0188 | B0188* | -- |
Evaporator Temperature Sensor Signal | B3933 06 | B3933 06 | B3933 06* | -- |
Low Reference | -- | B3933 06, B0158 06, B0163 06 | B3933 06, B0158 07, B0163 07 | B0158 07, B0163 07 |
Sunload sensors Ground Circuit | -- | B0183, B0188 | B0183, B0188 | -- |
* If the signal circuit is shorted to voltage B0158, B0163, B0183, B0188 and B3933 will all set | ||||
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 very bright. 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.
Conditions for Running the DTC
The ignition is turned 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 50 fault-free ignition cycles. |
Reference Information
Schematic Reference
Connector End View Reference
Description and Operation
Air Temperature Description and Operation
Electrical Information Reference
Scan Tool Reference
Circuit/System Testing
- Ignition OFF, disconnect the harness connector at the appropriate sunload sensor.
- Test for less than 1.0 ohm of resistance between the ground circuit terminal C and ground.
- Ignition ON, verify the appropriate sunload sensor parameter listed below is greater than 250 counts.
- 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 sunload sensor parameter is less than 5 counts.
- If all circuits test normal, test or replace the sunload sensor.
| ⇒ | If greater than the specified range, test the ground circuit for an open/high resistance. |
| • | Left sunload sensor circuit terminal A. |
| • | Right sunload sensor circuit terminal B. |
| ⇒ | If not the specified value, test the appropriate signal circuit terminal A or B 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. |
| ⇒ | 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. |
Repair Instructions
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
| • | Control Module References for HVAC control module replacement, setup and programming |
