• | 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. |
Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance |
---|---|---|---|---|
Door Ajar Switch Voltage Supply Circuit | 1 | 2 | -- | -- |
Dome Lamp Switch | 1 | 2 | -- | -- |
BCM | 1 | 2 | 2 | -- |
Door Ajar Switch | 1 | 2 | 2 | -- |
1. Courtesy Lamps Always ON 2. Courtesy Lamps Inoperative |
The courtesy lamps are controlled by the body control module (BCM). Inputs from the dome lamp switch and the door ajar switches are monitored by the BCM. When a door ajar switch is closed the BCM supplies the ground for the courtesy lamps or the dome lamp switch is turned to the ON position. The BCM also supplies the voltage for the courtesy lamps.
• | Check for the proper operation of the courtesy lamp bulbs. |
• | Check the position of the dome lamp switch. |
Ignition ON, observe the Scan Tool Door Lamp Command parameter while OPENING and CLOSING the drive door. The reading should change between OFF and ON.
⇒ | If greater than 1 ohm, test the ground circuit for an open/high resistance. |
⇒ | If the dome lamp command is not OFF, test the signal circuit for a short to ground. If the circuit tests normal, replace the BCM. |
⇒ | If the dome lamp command is not ON, test the signal circuit of the dome lamp switch for a short to voltage or an open/high resistance. If circuit tests normal, replace the BCM. |
⇒ | If the dome lamp command is not ON, test the signal circuit of the dome lamp switch for a short to voltage or an open/high resistance. If circuit tests normal, replace the BCM. |
Important: This test can be performed on any of the door ajar switches.
⇒ | If greater than 1 ohm, test the ground circuit for an open/high resistance. |
⇒ | If the dome lamp command is not OFF, test the signal circuit for a short to ground. If the circuit tests normal, replace the BCM. |
⇒ | If the dome lamp is not ON, test the signal circuit of the door ajar switch for a short to voltage or an open/high resistance. If circuit tests normal, replace the BCM. |
⇒ | If less than infinite resistance, replace the dome lamp switch. |
⇒ | If greater than 2.1 ohms, replace the dome lamp switch. |
Important: This test can be performed on any of the door ajar switches
⇒ | If less than infinite resistance, replace the door ajar switch. |
⇒ | If greater than 1 ohms, replace the door ajar switch. |
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
• | Control Module References for BCM replacement, setup, and programming |