Operation; Diagnosis And Testing - Headlamp - Chrysler 300M 2002 Service Manual

LH
HEADLAMP (Continued)

OPERATION

HEADLAMP SYSTEM
The headlamp system will default to the head-
lamps ON position when the ignition switch is ON,
or when an open/short circuit failure occurs on the
headlamp switch input. The system will return to
normal operation when the open or short is repaired.
A fault will be reported by the BCM when a failure
occurs on the dimmer or headlamp switch input.
The dimmer system will default to Daytime Bright-
ness when an open or a short occurs on the dimmer
switch input.
The BCM will turn OFF the exterior lamps if they
are left ON with the ignition switch OFF for more
than ten minutes. This feature prevents the vehicle
battery from being discharged when the vehicle
lights have been left ON.
AUTO HEADLAMP SYSTEM
Automatic headlamps are controlled by the Body
Control Module (BCM). With the headlamp switch in
the AUTO position (Automatic mode). The BCM will
control the headlamp, parking, side marker, tail and
instrumentation lamps based on ambient light levels.
CONDITION
HEADLAMPS ARE DIM
WITH ENGINE IDLING OR
IGNITION TURNED OFF
HEADLAMP BULBS BURN
OUT FREQUENTLY
HEADLAMP DIAGNOSIS
POSSIBLE CAUSES
1. Loose or corroded battery cables.
2. Loose or worn generator drive
belt.
3. Charging system output too low.
4. Battery has insufficient charge.
5. Battery is sulfated or shorted.
6. Poor lighting circuit Z1 ground.
7. Both headlamp bulbs defective.
1. Charging system output too high.
2. Loose or corroded terminals or
splices in circuit.
LAMPS/LIGHTING - EXTERIOR 8L - 15
Ambient light levels are monitored by the BCM using
the automatic temperature control system Sun Sen-
sor, located on the top of the instrument panel cover.
Ambient light readings are averaged to limit cycling
the lamps ON and OFF when passing through areas
with varying light levels. The automatic headlamps
will only function when the engine is running. When
the headlamp switch is in the AUTO position, the
Headlamp Time Delay system will function when the
ignition is switched OFF.

DIAGNOSIS AND TESTING - HEADLAMP

When a vehicle experiences problems with the
headlamp system, verify the condition of:
• Battery connections
• Charging system
• Headlamp bulbs
• Head lamp relay
• High beam dimmer switch
• Headlamp switch
• Body Control Module
• Wire connectors
Refer to Wiring Diagrams, for component locations
and circuit information.
1. Clean and secure battery cable clamps
and posts.
2. Adjust or replace generator drive belt.
3. Test and repair charging system, refer
to Electrical, Battery
4. Test battery state-of-charge, refer to
Electrical, Battery.
5. Load test battery, refer to Electrical,
Battery.
6. Test for voltage drop across Z1 ground
locations, refer to Wiring Diagrams.
7. Replace both headlamp bulbs.
1. Test and repair charging system, refer
to Electrical, Battery.
2. Inspect and repair all connectors and
splices, refer to Wiring Diagrams.
CORRECTION