JEEP XJ 1995 Service And Repair Manual

VEHICLE SPEED CONTROL
VEHICLE SPEED CONTROL
The vehicle speed control system is operated by the
Powertrain Control Module (PCM).
Circuit F12 from fuse 11 in the Power Distribution
Center (PDC) supplies battery voltage to the vehicle
speed control ON/OFF switch. Circuit A21 supplies
voltage to fuse 11 when the ignition switch is in the
START or RUN positions. In the START or RUN po-
sition the ignition switch connects circuit A21 with
circuit A1. Fuse 6 in the PDC protects circuit A1.
The vehicle speed control ON/OFF switch supplies
voltage to the SET/COAST and RESUME/ACCEL
switches. Both switches send signals to the PCM
(which supplies the ground path for the switches).
The PCM controls the vent and vacuum functions
of the speed control servo on circuits V35 and V36.
Depending on the signal it receives from the vehicle
speed control switches, the PCM either applies vac-
uum to, or vents vacuum from, the servo. Circuit V36
from cavity 33 of the PCM sends the vacuum signal
to the servo. Circuit V35 from cavity 53 sends the
vent signal.
Circuit V32 signals to the PCM that the speed con-
trol switch is in the ON position. The V32 circuit con-
nects to cavity 49 of the PCM.Circuit V31 provides the SET/COAST signal to cav-
ity 48 of the PCM. Circuit V33 sends the RESUME/
ACCEL signal to cavity 50 of the PCM.
Circuit K29 connects to cavity 29 of the PCM and
to ground through the stop lamp switch. The stop
lamp switch OPENS when the operator depresses the
brake pedal. The PCM disables speed control when
the stop lamp switch opens. From the stop lamp
switch, circuit Z1 provides ground for circuit K29.
DIAGRAM INDEX
Component Page
ABS Control Module......................8W-33-2
Fuse 4 (PDC)...........................8W-33-2
Fuse 6 (PDC)...........................8W-33-2
Fuse 11 (PDC)..........................8W-33-2
Ignition Switch..........................8W-33-2
Powertrain Control Module.................8W-33-2, 3
Stop Lamp Switch........................8W-33-2
Transmission Control Module.................8W-33-2
Vehicle Speed Control Servo.................8W-33-3
Vehicle Speed Control Switch.................8W-33-3
J8W-33 VEHICLE SPEED CONTROLÐXJ-RHD 8W - 33 - 1

INSTRUMENTCLUSTER

LOW WASHER FLUID WARNING LAMP
Circuit G29 connects the low washer fluid switch to
the warning lamp in the instrument cluster. Circuit
F12 supplies battery voltage to the switch.
When the low washer fluid switch closes, it con-
nects circuits G29 and F12. Battery voltage from cir-
cuit F12 powers the low washer fluid lamp. Circuit
Z1 at the instrument cluster provides ground to illu-
minate the warning lamp.
SEAT BELT INDICATOR WARNING LAMP
The seat belt indicator warning lamp is activated
by the chime/buzzer on circuit G11. Circuit G11 sup-
plies power to instrument cluster for the lamp. Cir-
cuit Z1 provides ground for the lamp at the cluster.
The chime/buzzer module powers circuit G11 after
it receives an input on circuit G10 indicating the seat
belt switch is open.
HIGH-BEAM INDICATOR LAMP
Circuit L3 supplies power for the high beam indi-
cator lamp. The ground path for the lamp is through
circuit Z1. Circuit Z1 provides ground for the indica-
tor lamp at the cluster.
ABS WARNING LAMP
Circuit F87 provides power for the ABS warning
lamp at the instrument cluster. Ground for the ABS
warning lamp is provided by either the ABS control
module or by the ABS power relay when the relay is
not energized. The ABS control module illuminates
the lamp by providing ground on circuit B205.
Circuit B205 splices to connect to circuit B235
through a diode. When the ABS power relay is not
energized, it connects circuit B235 to circuit Z12. The
ground path for the warning lamp is through the di-
ode to circuit B235, through the ABS power relay to
ground on circuit Z12.
The diode between circuits B205 and B235 pre-
vents voltage from flowing to the ABS control module
when the ABS power relay switches to supply power
on circuit B235.
TURN SIGNAL INDICATOR LAMPS
Circuits L61 and L60 power for the turn signal in-
dicator lamps. Circuit L61 powers the left indicator
lamp. Circuit L60 powers the right indicator lamp.
Circuit Z1 provides ground for the lamps.
BRAKE WARNING LAMP
Circuit F87 supplies power to the park brake lamp.
Ground for the park brake lamp is supplied through
the case grounded park brake switch or brake warn-
ing switch on circuit G9. Circuit G9 connects to the
brake warning lamp at the instrument cluster.
FOUR-WHEEL DRIVE (4WD) SWITCH
When the 4WD switch closes, circuit Z1 provides
ground for the 4WD indicator lamp in the instrument
cluster. Circuit F87 connects to the instrument clus-
ter and supplies battery voltage to the 4WD indicator
lamp. Circuit G107 connects the indicator lamp to
the 4WD switch. Circuit G106 connects the lamp to
the instrument cluster and circuit F87.
TACHOMETER
The Powertrain Control Module (PCM) supplies the
signal to the tachometer on circuit G21. Circuit G21
connects to cavity 43 of the PCM.
CLUSTER GROUND
Circuit Z1 from the instrument cluster left connec-
tor provides ground for the illumination lamps and
indicator lamps.
HELPFUL INFORMATION
²If the warning lamps don't operate, check fuse 26
in the fuse block.
²If the indicator lamps don't operate, check fuse 14
in the fuse block.
²If the illumination lamps don't operate, check fuse
25 in the fuse block.
8W - 40 - 2 8W-40 INSTRUMENT CLUSTERÐXJ-RHDJ