Diagnostic Instructions
DTC Descriptor
DTC B3801 00: Passenger Compartment Lamp Request Circuit
Circuit/System Description
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 directly illuminate the courtesy/dome lamps.
Conditions for Running the DTC
The battery voltage must be between 9-16 volts.
Conditions for Setting the DTC
The BCM detects the courtesy lamp switch is active while the IP lamp dimmer switch at the dim position.
Action Taken When the DTC Sets
The courtesy/dome lamps will be inoperative.
Conditions for Clearing the DTC
• | 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. |
Reference Information
Schematic Reference
Interior Lights Schematics
Connector End View Reference
Component Connector End Views
Description and Operation
Interior Lighting Systems Description and Operation
Electrical Information Reference
Scan Tool Reference
Control Module References for scan tool information
Circuit/System Testing
Dimmer Switch Malfunction
- Ignition OFF, disconnect the harness connector X1 at the headlamp switch.
- Ignition OFF, test for less than 5.0 ohms between the low reference circuit terminal H and ground.
⇒ | If greater than the specified range, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the BCM. |
- Verify the scan tool Dimming Input parameter is less than 1.0 volt.
⇒ | If greater than the specified range, test the signal circuit terminal G for a short to voltage. If the circuit tests normal, replace the BCM. |
- If all circuits test normal, replace the headlamp switch.
Courtesy Lamp Switch Malfunction
- Ignition OFF, disconnect the X1 harness connector at the headlamp switch.
- Ignition ON, verify the scan tool Courtesy Lamp Switch parameter is Inactive.
⇒ | If not the specified value, test the signal circuit terminal J for a short to ground. If the circuit tests normal, replace the BCM. |
- If all circuits test normal, replace the headlamp switch.
Repair Instructions
Perform the
Diagnostic Repair Verification after completing the diagnostic procedure.