B2618

CIRCUIT DESCRIPTION
The Body Control Module (BCM) controls the ground of the courtesy lamp relay on the courtesy lamp relay coil control circuit. When the BCM receives a signal from a door jamb switch, a signal to unlock the doors from the remote control door lock module receiver module or the dome lamp switch being turned ON, the BCM grounds the relay and turns ON the courtesy lamps.

CONDITIONS FOR RUNNING THE DTC
- The system voltage must be between 9 - 16 volts.
- The ignition switch in the OFF position.
- Unlock doors from the remote control door lock key fob, or open any door, or turn ON the dome lamp from the headlamp switch thumbwheel.
- The above conditions must be met for more than 0.5 seconds.

CONDITIONS FOR SETTING THE DTC
To set B2618, the following conditions must be present:
- Courtesy lamps ON.
- The courtesy lamp relay coil control circuit is shorted to battery voltage.
- The above conditions must be met for 0.5 seconds.

ACTION TAKEN WHEN THE DTC SETS
The courtesy lights will not function.

CONDITIONS FOR CLEARING THE MIL/DTC
- This DTC will clear after a fault free courtesy lamp operation.
- A history DTC will clear after 100 consecutive ignition cycles without a fault present.
- Use a scan tool in order to clear history and current DTCs.

DIAGNOSTIC AIDS

IMPORTANT: Use the appropriate probe from the J 35616-A connector test adapter kit for any probing of the electrical components in this table, in order to avoid damage to the terminals.

- The scan tool must display DTC B2618 as a current code before performing these diagnostics.
- Perform a visual inspection for loose or poor connections at all related components. Refer to Testing for Intermittent and Poor Connections in Diagrams.

TEST DESCRIPTION

Steps 1-3:

Steps 4-13:

The numbers below refer to the step numbers on the diagnostic table.
2. Listen for an audible click when the courtesy lamp relay operates. Command both the ON and OFF states. Repeat the commands as necessary.
3. Tests for voltage at the coil side of the courtesy lamp relay. The CTSY LP fuse supplies power to the coil side of the courtesy lamp relay.
4. Verifies that the body control module is providing ground to the courtesy lamp relay.
5. Tests if ground is constantly being applied to the courtesy lamp relay.
12. After replacement of the BCM you must calibrate the new module for proper operation.