Jeep 1997 Grand Cherokee Service Manual page 888

8W - 50 - 12
DESCRIPTION AND OPERATION
AUTO HEADLAMPS . . . . . . . . . . . . . . . . . . . . . 12
FOG LAMPS . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
HEADLAMP LEVELING . . . . . . . . . . . . . . . . . . . 12
DESCRIPTION AND OPERATION
INTRODUCTION
The vehicle is equipped with a Body Control Mod-
ule (BCM). The BCM controls the auto headlamp fea-
ture through the auto headlamp relay.
The park lamps operate when the headlamp switch
is in the ON or PARK position. Also, if the vehicle is
equipped with the Vehicle Theft Security System
(VTSS), the BCM powers the park lamps through the
park lamp relay if it senses unauthorized vehicle
operation.
Circuit A6 from fuse 13 in Power Distribution Cen-
ter (PDC), powers the headlamp switch through the
circuit breaker in the switch.
PARKING LAMPS
Circuit A6 from fuse 13 in the Power Distribution
Center (PDC) powers circuit 366 through fuse 17 in
the junction block. When the headlamp switch is in
the PARK lamp position, it connects circuit 366 to
circuit L90. Circuit L90 powers the parking lamps,
side marker lamps. Circuit L90 also connects to the
Body Control Module (BCM).
The BCM operates the park lamps when it senses
unauthorized entry to the vehicle while the Vehicle
Theft Security System is armed. When it sense unau-
thorized entry, the BCM energizes the park lamp
relay by providing ground for the relay coil on circuit
L79. Circuit 366 powers the relay coil and contacts.
When the relay energizes, it connects circuit 366 to
circuit L90.
HEADLAMPS
When the headlamp switch is in the LOW position,
it connects circuit A6 from fuse 13 in the Power Dis-
tribution Center (PDC) to circuit F34. Circuit F34
connects to the dimmer switch portion of the multi-
function switch and feeds circuit L4. Circuit L4 pow-
ers the low beam of the headlamps.
When the operator selects high beam operation or
flash-to-pass with the turn signal stalk of the multi-
function switch, circuit L11 from fuse 19 in the junc-
tion block connects to circuit L3. Circuit L3 powers
8W - 50 FRONT LIGHTING
8W-50 FRONT LIGHTING
INDEX
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headlamp high beams. Circuit L3 also connects to the
Body Control Module (BCM).
Canada, the Daytime Running Lamps (DRL) module
powers the headlamp high beams on circuit L3 when
the headlamp switch is off and the ignition switch is
in the RUN position.
HEADLAMP LEVELING
connects circuit A1 from fuse 8 in the Power Distri-
bution Center (PDC) to circuit A22. Circuit A22 pow-
ers circuit F83 through fuse 6 in the junction block.
Circuit F83 feeds the headlamp leveling switch. Cir-
cuit Z1 grounds the switch.
AUTO HEADLAMPS
Headlamp feature. The BCM monitors outside light
intensity through the auto headlamp light sensor.
Circuit L109 from the BCM provides 5 volts to the
sensor. Circuit L110 from the sensor sends the light
intensity signal to the BCM.
vides a signal to the BCM by connecting circuit L24
to ground on circuit Z1. If outside light intensity is
low enough when the BCM senses the AUTO head-
lamp request, it energizes the auto headlamp relay
by grounding the relay coil on circuit 714. Circuit A6
from fuse 13 in the Power Distribution Center (PDC)
powers the relay coil and contacts.
circuit F34. Circuit F34 powers circuit L4 through
the headlamp dimmer switch circuitry in the multi-
function switch. Circuit L4 powers the headlamps.
FOG LAMPS
high beams are off and the park lamps are on. The
fog lamp switch contains a light emitting diode
(LED) that illuminates during fog lamp operation.
Body Control Module (BCM) on circuit L35. If the
park lamps are on and the BCM does not sense head-
HEADLAMPS . . . . . . . . . . . . . . . . . . . . . . . . . . 12
INTRODUCTION . . . . . . . . . . . . . . . . . . . . . . . . 12
PARKING LAMPS . . . . . . . . . . . . . . . . . . . . . . . 12
If the vehicle was built for sale in the Country of
When the ignition switch is in the RUN position, it
The Body Control Module (BCM) operates the Auto
In the AUTO position, the headlamp switch pro-
When the relay energizes, it connects circuit A6 to
The fog lamps only operate when the headlamp
When the fog lamp switch closes, it signals the
ZG
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