A Symptoms - Lighting Systems

SYMPTOMS

IMPORTANT: The following steps must be completed before using the symptom tables.

1. Perform the Diagnostic System Check - Vehicle in Vehicle DTC Information, before using the symptom tables in order to verify that all of the following are true:
- There are no DTCs set.
- The body control module (BCM) can communicate via the serial data link. Diagnostic System Check - Vehicle
2. Review the system operation in order to familiarize yourself with the system functions. Refer to the following:
- Exterior Lighting Systems Description and Operation
- Interior Lighting Systems Description and Operation

Visual/Physical Inspection
Several of the symptom procedures ask for a careful visual/physical check. This step is extremely important, it could lead to correcting a problem without further checks and can save valuable time. These checks include the following:
- Inspect for aftermarket devices which could affect the operation of the Lighting System.
- Inspect the easily accessible or visible system components and harness connectors for obvious damage or conditions which could cause the symptom.
- If only one lamp is inoperative, inspect and repair a poor connection or an open in the power feed or ground circuit before replacing the light bulb.

Symptom List
Refer to a symptom diagnostic procedure from the following list in order to diagnose a symptom that does not set a DTC:
- Backup Lamps Always On
- Backup Lamps Inoperative
- Courtesy Lamps Always On
- Courtesy Lamps Inoperative (From I/P Dimmer Switch) Courtesy Lamps Inoperative (From Door Switch)
- Daytime Running Lamps (DRL) Indicator Inoperative
- Fog Lamps Always On
- Fog Lamps Inoperative
- Hazard Lamps Inoperative
- Headlamps Inoperative - Low Beams
- Headlamps Inoperative - High Beams
- Headlamps Inoperative - Low and High Beams
- Headlamps Inoperative - Flash to Pass
- High Beam Indicator Inoperative
- Park Lamps Inoperative
- Rear Compartment Lamp(s) Inoperative
- Reading Lamp(s) Inoperative
- Stop Lamps Inoperative
- Turn Signal Lamps and/or Indicators Inoperative