Symptoms - Lighting Systems. Buick Park Avenue 2003

Important: The following steps must be completed before using the symptom table.

•	Perform the Diagnostic System Check - Lighting Systems before using the Symptom Tables in order to verify that all of the following are true:

-	There are no DTCs set.

-	The control modules can communicate via the serial data link.

•	Review the system description and operation in order to familiarize yourself with the system functions. Refer to Interior Lighting Systems Description and Operation and Exterior Lighting Systems Description and Operation .

•	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.

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

Refer to a symptom diagnostic procedure from the following list in order to diagnose the symptom:

•	Backup Lamps Always On

•	Backup Lamps Inoperative

•	Cornering Lamps Always On

•	Cornering Lamps Inoperative

•	Courtesy Lamps Always On

•	Courtesy Lamps Inoperative

•	Daytime Running Lamps (DRL) Always On

•	Daytime Running Lamps (DRL) Inoperative

•	Hazard Lamps Always On

•	Hazard Lamps Inoperative

•	Headlamp Low or High Beams Always On

•	Headlamps Inoperative - High Beams

•	Headlamps Inoperative - Low Beams

•	Headlamps Flash to Pass Inoperative

•	High Beam Indicator Always On

•	High Beam Indicator Inoperative

•	Interior Backlighting Does Not Dim

•	Interior Backlighting Inoperative

•	Instrument Panel Compartment Lamp Inoperative

•	Instrument Panel Compartment Lamp Always On

•	License Lamps Inoperative

•	Park Lamps Always On

•	Park Lamps Inoperative

•	Reading Lamp Always On

•	Reading Lamp Inoperative

•	Rear Compartment Lamp Always On

•	Rear Compartment Lamp Inoperative

•	Stop Lamps Always On

•	Stop Lamps Inoperative

•	Turn Signal Lamps and/or Indicators Always On or Flashing

•	Turn Signal Lamps and/or Indicators Inoperative

•	Twilight Sentinel Inoperative

•	Vanity Mirror Lamp Always On

•	Vanity Mirror Lamp Inoperative