Circuit Description
The front fog lamp switch circuit provides a direct battery input to the BCM when the switch is pressed. This input allows the BCM to detect a front fog lamp switch ON or OFF request. If the BCM detects battery voltage on the front fog lamp switch signal circuit when the front fog lamps are OFF, the BCM will turn ON the lamps by energizing the front fog lamp relay. If the BCM detects battery voltage after the front fog lamps ON command, the BCM will turn OFF the lamps. The BCM monitors the front fog lamp switch signal circuit in order to determine how long the voltage has been applied. If the voltage is applied for longer than expected, a malfunction is present and a DTC will set.
Conditions for Setting the DTC
The BCM detects battery positive voltage on the front fog lamp switch signal circuit for longer than 60 seconds.
Action Taken When the DTC Sets
Stores a DTC B2403 in the BCM memory.
Conditions for Clearing the DTC
| • | The BCM no longer detects battery voltage on the front fog lamp switch signal circuit for longer than 60 seconds. |
| • | A history DTC will clear after 50 consecutive ignition cycles if the condition for the malfunction is no longer present. |
| • | Use the IPC clearing DTCs feature. |
| • | The BCM receives the Clear Code command from the scan tool. |
Diagnostic Aids
| • | The following conditions may cause an intermittent malfunction: |
| - | There is an intermittent short to voltage in the front fog lamp switch signal circuit. |
| - | The front fog lamp switch is internally shorted to battery positive voltage or is sticking. |
| - | The front fog lamp switch is pressed for longer than 60 seconds. |
| • | If the front fog lamp switch signal circuit is shorted to battery positive voltage, the front fog lamps will remain ON or OFF at all times depending on whether the lamps were ON or OFF when the short occurred. If the short occurredwhen the lamps were ON, the lamps will remain OFF at all times. If the short occurred when the lamps were OFF, the lamps will remain ON at all times. The BCM will remember whether the lamps were ON or OFF even if the ignition is switchedOFF. |
| • | If the DTC is a history DTC, the problem may be intermittent. Perform the tests shown while moving related wiring and connectors. This can often cause the malfunction to occur. Refer to Testing for Intermittent Conditions and Poor Connections in Wiring Systems. |
Test Description
The number(s) below refer to the step number(s) on the diagnostic table.
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Tests for the normal state of the front fog light switch using a scan tool. The scan tool will display the normal state as INACTIVE, and ACTIVE when the switch is activated.
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Tests if the BCM is able to detect a change in front fog light switch state. The scan tool will display the normal state as INACTIVE, and ACTIVE when the switch is activated.
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Tests for a stuck or shorted front fog light switch. If the front fog light switch is stuck or shorted, the state will change from ACTIVE to INACTIVE when the front fog light switch is disconnected.
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Tests for a short to battery positive voltage in the front fog light switch signal circuit.
Step | Action | Yes | No |
|---|---|---|---|
Schematic Reference: Fog Lights Schematics Connector End View Reference: Master Electrical Component List | |||
1 | Did you perform the Lighting System Diagnostic System Check? | Go to Step 2 | |
Does the scan tool display INACTIVE? | Go to Step 3 | Go to Step 4 | |
Does the Front Fog Light Switch parameter change state? | Go to Diagnostic Aids | Go to Step 4 | |
Does the scan tool display INACTIVE? | Go to Step 7 | Go to Step 5 | |
Test the front fog light switch signal circuit for a short to voltage. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 10 | Go to Step 6 | |
6 | Inspect for poor connections at the harness connector of the BCM. 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 10 | Go to Step 8 |
7 | Inspect for poor connections at the harness connector of the front fog light switch. 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 10 | Go to Step 9 |
8 |
Important: Perform the BCM reprogram procedure. Refer to Body Control Module (BCM) Programming/RPO Configuration in Body Control System. Replace the BCM. Refer to Body Control Module Replacement in Body Control System. Did you complete the replacement? | Go to Step 10 | -- |
9 | Replace the front fog light switch. Refer to Fog Lamp Switch Replacement . Did you complete the replacement? | Go to Step 10 | -- |
10 |
Does the DTC reset? | Go to Step 2 | System OK |
