Circuit Description
The twilight photocell sensor is a light sensitive photocell. The climate control panel (CCP) determines the ambient light based on the voltage from the twilight photocell sensor. The CCP controls the head lamp automatic on/off and delayed off functions.
Conditions for Running the DTC
| • | Enable flag is set to enable. |
| • | DTC B1327 is not current. |
| • | The CCP is powered. |
Conditions for Setting the DTC
| • | The twilight photocell voltage is greater than 4.8 V. |
| • | The above condition is present for greater than 2 seconds. |
Action Taken When the DTC Sets
| • | CCP sets the variable ambient light status to status set to DARK. |
| • | The CCP sets a DTC. |
Conditions for Clearing the MIL/DTC
The CCP does not detect a voltage greater than the predetermined value during the diagnostic self test.
Test Description
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 | Value(s) | Yes | No |
|---|---|---|---|---|
1 | Did you perform the Lighting Systems Diagnostic System Check? | -- | Go to Step 2 | |
2 |
Does the scan tool indicate that the ambient light sesnor parameter is within the specified range? | 0.2-4.8 V | Go to Step 9 | Go to Step 3 |
Does the scan tool indicate that the ambient light sensor data parameter is greater than the specified value? | 4.8 V | Go to Step 4 | Go to Step 5 | |
Does the scan tool indicate that the ambient light sensor data parameter is less than the specified value? | 0.2 V | Go to Step 8 | Go to Step 6 | |
5 | Test the signal circuit of the ambient light sensor for a short to ground. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 12 | Go to Step 9 |
6 | Test the signal circuit of the ambient light sensor for a open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 12 | Go to Step 7 |
7 | Test the signal return circuit of the ambient light sensor for high resistance or an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 12 | Go to Step 9 |
8 | Inspect for poor connections at the harness connector of the ambient light sensor. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 12 | Go to Step 10 |
9 | Inspect for poor connections at the harness connector of the CCP. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 12 | Go to Step 11 |
10 | Replace the ambient light sensor. Refer to Sunload and Twilight Sentinel Sensor Replacement in Instrument Panel, Gauges and Console. Did you complete the replacement? | -- | Go to Step 12 | -- |
11 | Replace the CCP. Refer to Control Assembly Replacement in HVAC Systems with A/C - Manual. Did you complete the replacement? | -- | Go to Step 12 | -- |
12 |
Does the DTC reset? | -- | Go to Step 2 | System OK |
