The body control module (BCM) monitors the courtesy lamp switch signal circuit in order to determine when the courtesy/dome lamps should be illuminated. When the BCM senses that the courtesy lamp switch signal circuit is grounded when the switch is activated, the BCM will illuminate the courtesy/dome lamps.
This diagnostic procedure supports the following DTC:
DTC B3801 Passenger Compartment Lamp Request Circuit
• | The BCM instrument panel dimmer switch reference voltage must be between 4.5-5.5 volts. |
• | The battery voltage must be between 9.0-16.0 volts. |
• | When the instrument panel dimmer switch signal is greater than 1.0 volt. |
• | When the BCM receives a courtesy lamp ON request signal from the courtesy lamp switch. |
The courtesy/dome lamps will not operate.
• | This DTC will clear on current status after the condition for setting the fault is corrected. |
• | A history DTC will clear after 100 consecutive ignition cycles without a fault present. |
• | History and current DTCs can be cleared using a scan tool. |
• | Test the courtesy lamp switch for sticking in the ON position. |
• | Perform a visual inspection for loose or poor connections at all related components. Refer to Testing for Intermittent Conditions and Poor Connections in Wiring Systems. |
Step | Action | Yes | No |
---|---|---|---|
Schematic Reference: Interior Lights Schematics Connector End View Reference: Lighting Systems Connector End Viewsor Computer/Integrating Systems Connector End Views in Computer/Integrating Systems | |||
1 | Did you perform the Diagnostic System Check - Vehicle? | Go to Step 2 | Go to Diagnostic System Check - Vehicle in Vehicle DTC Information |
2 |
Does the scan tool display as expected? | Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems | Go to Step 3 |
3 |
Does the scan tool display ACTIVE? | Go to Step 4 | Go to Step 6 |
4 | Test the signal circuit of the courtesy lamp switch 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 9 | Go to Step 5 |
5 | Inspect for poor connections at the harness connector of the BCM. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 9 | Go to Step 7 |
6 | Inspect for poor connections at the harness connector of the headlamp switch. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 9 | Go to Step 8 |
7 | Replace the BCM. Refer to Control Module References in Computer/Integrating Systems for replacement, setup, and programming. Did you complete the replacement? | Go to Step 9 | -- |
8 | Replace the headlamp switch. Refer to Headlamp Switch Replacement. Did you complete the replacement? | Go to Step 9 | -- |
9 |
Does the DTC reset? | Go to Step 2 | System OK |