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 vehicle.
• | Sunload sensor 1 refers to the left sunload sensor |
• | Sunload sensor 2 refers to the right sunload sensor |
This diagnostic procedure supports the following DTCs:
• | DTC B0184 Sunload Sensor 1 Circuit Performance |
• | DTC B0189 Sunload Sensor 2 Circuit Performance |
The ignition is turned ON.
The HVAC control module detects the signal circuit is less than 0.09 volt (5 counts) or more than 4.90 volts (250 counts).
• | If the DTC sets due to a low voltage condition, the HVAC control module will operate the system as if a minimum 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. |
• | The DTC will become history if the HVAC control module no longer detects a failure. |
• | The history DTC will clear after 50 fault free ignition cycles. |
• | The DTC can be cleared with a scan tool. |
The numbers below refer to the step numbers on the diagnostic table.
Tests for the proper operation of the circuit in the high voltage range.
Tests for the proper operation of the circuit in the low voltage range. If the fuse in the jumper opens when you perform this test, the signal circuit is shorted to voltage.
Step | Action | Values | Yes | No | ||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Schematic Reference: HVAC Schematics Connector End View Reference: HVAC Connector End Views | ||||||||||||||
1 | Did you perform the Diagnostic System Check - Vehicle? | -- | Go to Step 2 | |||||||||||
2 |
Does the scan tool indicate that the Solar Sensor parameter is with in the specified range? | 0.09-4.90 V | Go to Testing for Intermittent Conditions and Poor Connections | Go to Step 3 | ||||||||||
Does the scan tool indicate that the Solar Sensor parameters are greater than the specified value? | 4.90 V | Go to Step 4 | Go to Step 5 | |||||||||||
Does the scan tool indicate that the Solar Sensor parameter is less than the specified value? | 0.09 V | Go to Step 9 | Go to Step 6 | |||||||||||
5 | Test the driver or passenger signal circuit of the sunload sensor assembly for a short to ground. Refer to Circuit Testing and Wiring Repairs . Did you find and correct the condition? | -- | Go to Step 13 | Go to Step 10 | ||||||||||
6 | Test the driver or passenger signal circuit of the sunload sensor assembly for a short to voltage, a high resistance, or an open. Refer to Circuit Testing and Wiring Repairs . Did you find and correct the condition? | -- | Go to Step 13 | Go to Step 7 | ||||||||||
7 | Test the low reference circuit of the sunload sensor assembly for a high resistance or an open. Refer to Circuit Testing and Wiring Repairs . Did you find and correct the condition? | -- | Go to Step 13 | Go to Step 8 | ||||||||||
8 | Test the following signal circuits for a short to voltage:
Refer to Circuit Testing and Wiring Repairs . Did you find and correct the condition? | -- | Go to Step 13 | Go to Step 10 | ||||||||||
9 | Inspect for poor connections at the harness connector of the sunload sensor assembly. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs . Did you find and correct the condition? | -- | Go to Step 13 | Go to Step 11 | ||||||||||
10 | Inspect for poor connections at the harness connector of the HVAC control module. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs . Did you find and correct the condition? | -- | Go to Step 13 | Go to Step 12 | ||||||||||
11 | Replace the sunload sensor assembly. Refer to Sun Load Sensor Replacement . Did you complete the replacement? | -- | Go to Step 13 | -- | ||||||||||
12 | Replace the HVAC control module. Refer to Control Module References for replacement, setup and programming. Did you complete the replacement? | -- | Go to Step 13 | -- | ||||||||||
13 |
Does the DTC reset? | -- | Go to Step 2 | System OK |