Jeep 1997 Grand Cherokee Service Manual page 932

8W - 61 - 6
DESCRIPTION AND OPERATION
INTRODUCTION
The Drivers Door Module (DDM) powers the driv-
ers door lock motor. The Passengers Door Module
(PDM) powers the passenger, both rear doorlock and
the liftgate lock motors. The DDM and PDM each
contain a door lock switch. When one of the switches
is activated, a signal is sent on the CCD Bus to the
other door module (PDM or DDM depending on
which switch activated) to either LOCK or UNLOCK
the lock motors. The Remote Keyless Entry transmit-
ter can also LOCK or UNLOCK the door lock and
liftgate lock motors. The PDM contains the radio fre-
quency receiver that receives the RKE transmitter
signals.
The vehicle is equipped with a Rolling Door Lock
feature. When this feature is enabled, the PDM will
lock the doors and liftgate after the vehicles reaches
approximately 15 MPH.
POWER DOOR LOCKS
Circuit A250 from fuse 11 in the Power Distribu-
tion Center (PDC) powers circuit F81 through the cir-
cuit breaker in cavity 2 of the junction block. Circuit
F81 supplies power to the Drivers Door Module
(DDM) and the Passengers Door Module (PDM). The
DDM and PDM operate the power door locks. Circuit
Z1 provides ground for the power door locks.
The PDM contains the radio frequency receiver
that receives the radio frequency signals from the
Remote Keyless Entry (RKE) transmitter. After
either the passenger door lock switch activates or it
receives input from the RKE transmitter, the PDM
sends the appropriate signal to the DDM over the
8W - 61 POWER DOOR LOCKS
8W-61 POWER DOOR LOCKS
CCD Bus. When the DRIVERS door lock switch acti-
vates, the DDM sends the appropriate signal to the
PDM.
After receiving a LOCK signal, the DDM supplies
battery voltage to the left front door lock motor on
circuit P36. The DDM also connects circuit P34 from
the motor to ground.
When the DDM receives the UNLOCK signal, it
powers circuit P34 and grounds circuit P36.
After receiving a LOCK signal, the PDM supplies
battery voltage to the right front door lock motor,
rear door lock motors and liftgate lock motors on cir-
cuit P2. The PDM also connects circuit P34 from the
motor to ground.
When the DDM receives the UNLOCK signal, it
powers circuit P34 and grounds circuit P2.
REMOTE KEYLESS ENTRY
The Remote Keyless Entry (RKE) transmitter
sends three unique signals to the radio frequency
receiver in Passengers Door Module (PDM): LOCK,
UNLOCK and PANIC. After it receives any one of
the three signals, the PDM broadcasts the appropri-
ate signal over the CCD bus.
LIFTGLASS
Circuit A250 from fuse 11 in the Power Distribu-
tion Center (PDC) powers circuit F70 through fuse 8
in the junction block. If the liftglass limit switch is
closed, it connects circuit F70 to the liftglass switch
(push button) on circuit P101. When closed, the lift-
glass switch connects circuit P101 to circuit P100.
Circuit P100 feeds the liftglass solenoid. Circuit Z1
grounds the solenoid.
ZG