A Symptoms - Lighting Systems

1. Perform the A Diagnostic System Check - Lighting Systems before using the Symptom Tables in order to verity that all of the following are true:
- There are no DTCs set.
- The control module(s) can communicate via the serial data link.
2. Review the system operation in order to familiarize yourself with the system functions. Refer to:
- Headlights Circuit Description
- Headlights/Daytime Running Lights (DRL) Circuit Description
- Fog Lights Circuit Description
- Exterior Lights Circuit Description
- Backup Lights Circuit Description
- Interior Lights Circuit Description
- Trailer/Brake Controller Wiring Information

Visual/Physical Inspection
- Inspect for aftermarket devices which could affect the operation of the Lighting System. Refer to Checking Aftermarket Accessories in Wiring Systems.
- Inspect the easily accessible or visible system components for obvious damage or conditions which could cause the symptom.

Intermittent
Faulty electrical connections or wiring may be the cause of intermittent conditions. Refer to Testing for Intermittent and Poor Connections in Wiring Systems.

Symptom List
Refer to a symptom diagnostic procedure from the following list in order to diagnose the symptom:
- Backup Lamps Always On
- Backup Lamps Inoperative
- Backup Lamp Inoperative One Lamp
- Cargo Lamp Always On
- Cargo Lamp Inoperative
- CARGO LAMP ON Message Always On
- CARGO LAMP ON Message Inoperative
- Clearance Lamps Inoperative
- Courtesy Lamps inoperative
- Courtesy or Dome Lamps Always On
- Courtesy or Dome Lamps Inoperative
- Courtesy Lamps Inoperative with IP Dimmer Switch
- Courtesy/Reading Lamps Inoperative W/ Lamp Switch
- Dome Lamps Inoperative with LF Door Open
- Dome Lamps Inoperative with IP Dimming Switch
- Daytime Running Lamps (DRL) Headlamps Always On
- Daytime Running Lamps (DRL) Headlamps Inoperative
- Exterior Courtesy Lamp(s) Always On
- Exterior Courtesy Lamp(s) Inoperative
- Fog Lamp Indicator Inoperative
- Fog Lamps Always On
- Fog Lamps Inoperative - All
- Fog Lamp Switch Illumination Lamp Inoperative
- Hazard Lamps Inoperative
- Headlamps Inoperative - Left Low Beam
- Headlamps Inoperative - Right Low Beam
- Headlamps Inoperative - Low Beams
- Headlamps Inoperative - Left High Beam
- Headlamps Inoperative - Right High Beam
- Headlamps Inoperative - High Beams
- Headlamps Inoperative - Flash to Pass
- Headlamps Inoperative - Low and High Beams
- Headlamps Inoperative in Low Light Conditions
- Headlamps On in Daylight Conditions
- Headlamps Do Not Switch Intensity
- Headlamps, Daytime Running Lamps (DRL) On With Park Brake Applied
- High Beam Indicator Always On
- High Beam Indicator Inoperative
- Instrument Cluster Illumination Lamps Inoperative
- IP Compartment Lamp Inoperative
- Vanity Mirror Lamp(s) Inoperative
- Vanity Mirror Lamp(s) Always On
- Underhood Lamp Inoperative
- Instrument Panel Lamps Do Not Dim
- Instrument Panel Lamps Inoperative
- Window Switch Lamp Inoperative
- Lamps Inoperative - Switch
- License Lamps Inoperative
- Park Lamps Inoperative
- Park Lamps Inoperative - Front
- Park Lamp Inoperative - LF
- Park Lamp Inoperative - RF
- Side Marker Lamp Inoperative - One Lamp
- Stop Lamps Inoperative
- Stop Lamps Inoperative - Center High Mounted
- Stop Lamps Always On
- Tail Lamps Inoperative - LR
- Tail Lamps Inoperative - RR
- Turn Signal Lamps Inoperative
- [1][2]Turn Signal Lamp Inoperative - LF
- [1][2]Turn Signal Lamp Inoperative - RF
- Turn Signal Lamps Inoperative - Left or Right Side
- Turn Signal Lamps Inoperative - LR
- [1][2]Turn Signal Lamp Inoperative - RR
- Turn Signal Indicators Inoperative - Left
- Turn Signal Indicators Inoperative - Right
- Vacuum Fluorescent (VF) Displays Do Not Dim W/ IP Dimmer Switch