Jeep 1997 Grand Cherokee Service Manual page 955

ZG
DESCRIPTION AND OPERATION (Continued)
A bus bar internal to the switch connects circuit P12
to ground on circuit Z1.
For REAR VERTICAL DOWN function the circuits
are reversed. P12 is the feed, and P10 is the ground.
When the operator selects the FRONT VERTICAL
UP function, the switch passes power from circuit
F35 to circuit P18. Circuit P18 connects to the motor.
Ground is provided on circuit P20 back to the switch.
A bus bar internal to the switch connects circuit P20
to ground on circuit Z1.
For FRONT VERTICAL DOWN function the cir-
cuits are reversed. P20 is the feed, and P18 is the
ground.
When the operator selects the RECLINE UP func-
tion, the switch passes power from circuit F35 to the
P44 circuit. Circuit P44 connects to the motor.
Ground is provided on circuit P42 back to the switch.
A bus bar internal to the switch connects circuit P42
to ground on circuit Z1.
For RECLINE DOWN function the circuits are
reversed. P42 is the feed, and P44 is the ground.
MEMORY SEATS
Circuit A7 from fuse 15 in the Power Distribution
Center (PDC) powers circuit F35 through the circuit
breaker in cavity 3 of the junction block. Circuit F35
powers the Memory Seat Module (MSM). Circuit Z1
provides ground for the MSM.
When the operator moves the power seat switch or
the lumbar adjustment switch, contacts in the switch
CLOSE connecting the switch to the MSM. The MSM
receives this input and operates the proper seat
motor.
The drivers memory seat system can be activated
by either one of the memory switches on the left door
panel or through the Remote Keyless Entry (RKE)
transmitter. If one of the memory switches on the
door panel is pushed, the Drivers Door Module
(DDM) signals the MSM on the CCD bus. If the
memory function is activated by the RKE transmit-
ter, the Passenger Door Module (PDM) signals the
MSM on the CCD bus.
The following is a list of the circuits that connect
from the power seat switch to the MSM and their
functions:
• P40 - Recliner up
• P48 - Recliner down
• P19 - Front up
• P21 - Front down
• P11 - Rear up
• P13 - Rear down
• P15 - Seat forward
• P17 - Seat rearward
• P104 – lumbar rearward
• P105 – lumbar forward
8W - 63 POWER SEAT
To operate the seat motor(s), the control module
supplies the power and ground. The following is a list
of the circuits that connect from the control module
to the seat motors:
• P119, P121 - Seat front up and down
• P111, P113 - Rear up and down
• P115, P117 - Seat forward and rearward
• P41, P43 - Recliner forward and rearward
• P106, P107 – Lumbar forward and rearward
SEAT POSITION SENSORS
The Memory Seat Module (MSM) receives seat
position inputs from five sensors in the driver's seat.
On circuit P29, the MSM supplies power to the seat
position sensors on circuit P29. The MSM provides
ground for the sensors on circuit P28.
Circuit P25 provides the input from the horizontal
forward/rearward motor sensor to the MSM. Circuit
P47 provides the input from the recline motor sensor.
Circuit P103 sends the lumbar motor sensor input.
Circuit P27 provides the input from the rear riser
motor sensor to the MSM. Circuit P26 provides the
input from the front riser motor sensor. Circuit P29
from the MSM powers the riser motor sensors. The
MSM provides ground for the riser motor sensors on
circuit P28.
MEMORY SWITCH
The memory switch is used for programming the
desired seat positions into the MSM memory. The
memory switch also programs power mirror position
into the Drivers Door Module (DDM) and the Passen-
gers Door Module (PDM), and presets radio station
selections.
Circuit P22 from DDM supplies power to the three
sets of switches in the memory switch; set, memory
1, and memory 2. The three switch sets are wired in
parallel and each contains a separate resistor. The
voltage level present on circuit P22 depends on which
memory switch is activated. Circuit Z1 from the
DDM provides ground for the switches.
After a memory switch activates, the DDM broad-
casts the appropriate signal on CCD bus. The MSM
adjusts seat position in response to the signal.
Circuit M1 from the DDM powers the green Light
Emitting Diodes (LED) in the set switch. Circuit G49
powers the red LED in the set switch. Circuit Z1 pro-
vides ground for the LEDs.
HEATED SEATS
Separate control modules operate the driver and
passenger heated seats. Circuit F35 from the circuit
breaker in cavity 3 of the junction block supplies
power to both heated seat control modules. Circuit
A7 from fuse 15 in the Power Distribution Center
(PDC) powers circuit F35 through the circuit breaker.
8W - 63 - 17