For 1990-2009 cars

### Diagnostic Instructions

• | Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.

• | Review Strategy Based Diagnosis for an overview of the diagnostic approach.

• | Diagnostic Procedure Instructions provides an overview of each diagnostic category.

### Diagnostic Fault Information

Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance
--- | --- | --- | --- | ---
BCM | 1 | 1 | -- | --
1. Illuminated Entry Inoperative

### Circuit/System Description

The courtesy lamp supply voltage of the body control module (BCM) supplies battery positive voltage to the dome lamp, the liftgate lamp, and the map lamps. When any door is opened, the door jamb switch contacts close providing a door open input to the BCM. The BCM then provides a ground to the interior lamps with the switch in the AUTO position. The interior lamps receive a ground at G401 with the switch in the ON position.

### Diagnostic Aids

• | A malfunction in the door unlock system would cause the illuminated entry inoperative.

• | An open/high resistance in the BCM may cause a malfunction to occur.

• | The dome lamp switch in the OFF position will cause a malfunction to occur.

### Reference Information

#### Schematic Reference

Interior Lights Schematics

#### Connector End View Reference

Lighting Systems Connector End Views

#### Electrical Information Reference

• | Circuit Testing

• | Connector Repairs

• | Testing for Intermittent Conditions and Poor Connections

• | Wiring Repairs

#### Scan Tool Reference

• | Scan Tool Data Definitions

• | Scan Tool Data List

• | Scan Tool Output Controls

### Circuit/System Verification

Ignition ON, turn the headlamp switch to the park position. Observe the instrument panel lamps. The instrument panel lamp should be ON and while rotating the dimmer switch the instrument panel lamps should change brightness.

If the liftgate is opened after all the modules go to sleep, the dome light will not come on. The liftgate ajar switch input to the BCM will not wake up the BCM once it has gone to sleep, so the dome light will not come on. Once the BCM gets an input to wake it up from the remote keyless entry (RKE) or a door handle, the dome light will turn on when the liftgate is opened. If the driver inadvertently leaves any interior lamp ON, the BCM will turn it OFF after a 20-minute time out. The courtesy lamps will turn OFF immediately if the ignition switch is turned to the ON position or approximately 20 seconds after all doors are closed.

### Circuit/System Testing

1. Ignition OFF, lock and close all of the doors.
2. Ignition OFF, wait 20 seconds, use a remote keyless entry transmitter to unlock the doors and to see if the illuminated entry turns ON.

⇒ | If the illuminated entry does not turn ON, replace the BCM.

### Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Control Module References for BCM replacement, setup, and programming