Sable V6-3.0L VIN 2 Flex Fuel (2005)
Daytime Running Lamp: Initial Inspection and Diagnostic Overview
Principles of Operation
PRINCIPLES OF OPERATION
Daytime Running Lamps (DRL) The daytime running lamps (DRL) are controlled by the smart junction box (SJB). It operates the low beam headlamps
at a reduced intensity. The DRL driver (integral to the SJB) supplies pulse-width modulated (PWM) voltage, approximately 75% - 92% of battery
voltage, to the low beam headlamps when the following conditions are met:
-
the high beam headlamps are disabled.
-
the ignition switch is in the RUN position.
-
the parking brake switch is not engaged.
Inspection and Verification
INSPECTION AND VERIFICATION
1. Verify the customer concern.
2. Visually inspect for obvious signs of electrical damage.
VISUAL INSPECTION CHART
Electrical
-
Smart junction box (SJB)
-
Circuitry
3. Make sure the headlamps operate correctly. Correct any concerns before proceeding to the next step. Refer to Headlamp for any headlamp
concerns.
4. Make sure the parking brake control is fully released.
5. If an obvious cause for an observed or reported concern is found, correct the cause (if possible) before proceeding to the next step.
6. If the concern remains after the inspection, determine the symptom and GO to Symptom Chart. See: Symptom Related Diagnostic Procedures
