The body control module (BCM) controls the interior illumination. The BCM turns on the interior courtesy lamps when the following actions occur:
• | Any of the vehicle doors are opened. |
• | The dimmer switch is turned to the DOME position. |
• | Exit illumination is active. |
• | The doors are unlocked through the keyless entry system (BCM type 3 and type 4 only). |
• | The doors are unlocked using the door key cylinder (BCM type 4 only). |
The BCM turns the interior lamps off when all the vehicle doors are closed and the dimmer switch is in the OFF position.
All the vehicle doors contain a door lock ajar switch. When the driver door is open, the left front door lock ajar switch closes and sends a ground signal to the BCM through the driver door switch signal circuit.
When one of the right front, left rear, or right rear doors is open, its corresponding door lock ajar switch closes and sends a ground signal to the BCM through the corresponding door ajar input circuit. The BCM grounds the courtesy lamps low control circuit when detecting a ground signal in any of the following circuits:
• | Driver door switch signal circuit |
• | Sliding door switch signal circuit |
• | Door open switch signal circuit |
When the driver door is closed, the left front door lock ajar switch opens the driver door switch signal circuit. When any door is closed, their corresponding door lock ajar switch opens the corresponding door switch signal circuit. The BCM opens the courtesy lamps low control circuit when all of the door switch signal circuits are open.
The BCM powers the interior lights through the courtesy lamps supply voltage circuit. The BCM deactivates the courtesy lamps supply voltage circuit during inadvertent load battery rundown protection. The BCM also opens the courtesy lamps low control circuit when the inadvertent battery power rundown protection is active.
The BCM detects a short to ground or battery voltage in courtesy lamps low control circuit.
• | The BCM sets the diagnostic trouble code (DTC) 3. |
• | The courtesy lamps are disabled when the courtesy lamps low control circuit is shorted to battery positive voltage. |
• | The courtesy lights remain on when the courtesy lamps low control circuit is shorted to ground. |
• | A short to battery positive voltage in the courtesy lamps low control circuit is no longer present between the BCM and any of the courtesy lamps. |
• | A short to ground in the courtesy lamps low control circuit is no longer present between the BCM and any of the courtesy lamps. |
• | After the repairs are completed, clear the DTC. Refer to On-Board Diagnostic Features . |
• | If the problem is intermittent, the diagnostic code may still set. Refer to Testing for Intermittent Conditions and Poor Connections in Wiring Systems. |
• | The following conditions may cause an intermittent malfunction to occur: |
- | Inspect for an intermittent short to battery positive voltage in the courtesy lamp low control circuit. |
- | Inspect for an intermittent short to ground in the courtesy lamp low control circuit. |
Perform the following procedure in order to change the interior lighting mode:
The BCM sounds the chime a number of times equivalent to the BCM type installed on the vehicle. At this time the BCM has entered the feature customizing mode. In order to change the interior lighting, cycle the dimmer switch from the OFF position to the DOME position and then back to the OFF position. The BCM sounds a chime a number of times equal to the lighting mode.
The lighting modes are as follows:
• | Mode 1 - Exit illumination and delayed illumination are disabled. |
• | Mode 2 - Delay illumination is enabled. |
• | Mode 3 - Exit illumination is enabled. |
• | Mode 4 - Exit illumination and delayed illumination are enabled. |
The numbers below refer to the step numbers on the diagnostic table.
Always perform the lighting diagnostic system check before attempting to diagnose DTC 3.
Tests for a short to battery positive voltage in the courtesy lamps low control circuit.
If all the courtesy lamps illuminate when the courtesy lamps supply voltage is connected to battery positive voltage, the courtesy lamps low control circuit has a short to ground.
Step | Action | Yes | No |
---|---|---|---|
Schematic Reference: Interior Lights Schematics Connector End View Reference: Master Electrical Component List in Wiring Systems | |||
Did you perform the lighting diagnostic system check? | Go to Step 2 | ||
2 |
Are the footwell courtesy lamps illuminated? | Go to Step 4 | Go to Step 3 |
Does the test lamp illuminate? | Go to Step 5 | Go to Diagnostic Aids | |
Do the footwell courtesy lamps illuminate? | Go to Step 6 | Go to Step 7 | |
5 | Repair a short to battery positive voltage in the courtesy lamps low control circuit of the BCM. Refer to Wiring Repairs in Wiring Systems. Is the repair complete? | Go to Step 8 | -- |
6 | Repair a short to ground in the courtesy lamps low control circuit of the BCM. Refer to Wiring Repairs in Wiring Systems. Is the repair complete? | Go to Step 8 | -- |
7 | Replace the BCM. Refer to Body Control Module Replacement in Body Control System. Is the repair complete? | Go to Step 8 | -- |
8 |
Are any BCM DTCs present? | Go to Diagnostic Trouble Code (DTC) List in Body Control System | System OK |