1. ZJ POWER LOCKS 8P - 1 POWER LOCKS CONTENTS page pageDIAGNOSIS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 SERVICE PROCEDURES ................... 4GENERAL INFORMATION . . . . . . . . . . . . . . . . . . 1 GENERAL INFORMATION Power locks are standard equipment on Grand keyless entry module by sending the correct batteryCherokee models. Power windows and the keyless en- and ground feeds to the lock motors. The lock andtry system are included on vehicles equipped with unlock relays can not be repaired. If faulty, theypower locks. All doors and the liftgate can be locked must be replaced.and unlocked electrically by operating the switch oneither front door panel, or by operating the lock and POWER LOCK MOTORunlock buttons of the remote keyless entry transmit- The locks are actuated by a reversible motorter. The power lock and keyless entry systems oper- mounted within each door. The motor direction isate with battery power supplied independent of the controlled by the battery and ground feeds from theignition switch. power lock/unlock relays. The motor can not be re- A liftgate liftglass is an option on the Grand Cher- paired. If faulty, the entire motor must be replaced.okee model. The liftglass latch operates with batterypower supplied independent of the ignition switch. KEYLESS ENTRY TRANSMITTERThe liftglass latch solenoid is mounted near the lift- The keyless entry transmitter is equipped with twogate wiper motor inside the liftgate. The liftglass buttons labeled Lock and Unlock. It is also designedlatch release switch is mounted in the top of the li- to serve as a key fob and is equipped with a key ring.cense plate tub. A limit switch in the liftgate latch Each transmitter has a different vehicle access code,opens to prevent unauthorized liftglass latch opera-tion when the liftgate latch is locked with a power which must be programmed into the memory of thelock switch, the keyless entry transmitter or the lift- keyless entry module in the vehicle in order to oper-gate lock key cylinder. Refer to Group 23 - Body ate the locks. The operating range of the infraredComponents for service of the liftglass latch compo- transmitter signal is up to 4.75 meters (15 feet) fromnents. the receiver. Following are general descriptions of the major The transmitter operates on two CR1616 3-volt (orcomponents in the power lock and keyless entry sys- equivalent) batteries. Typical battery life is from onetems. Refer to Group 8W - Wiring Diagrams for com- to two years.plete circuit descriptions and diagrams. Refer to theowner’s manual for more information on the features KEYLESS ENTRY MODULEand use of these systems. The keyless entry module is mounted in the dome lamp housing on the headliner, or inside and towardsPOWER LOCK SWITCH the rear of the overhead console (if equipped). This The power locks are controlled by a two-way switch module contains the keyless entry receiver and pro-mounted on the trim panel of each front door. The gram logic for the keyless entry system.switch controls battery feed to the lock and unlock The keyless entry module has a memory functionrelays. The door lock switches can not be repaired. If to retain the vehicle access code of at least one, andfaulty, the entire switch must be replaced. up to four transmitters. The module receives input from the remote keyless entry transmitter. In re-POWER LOCK/UNLOCK RELAYS sponse to that input, it is programmed to control out- The power lock and unlock relays are located in the puts to the lock and unlock relays. The module canrelay center. The relay center is located under a not be repaired and, if faulty, must be replaced.cover in the bottom of the glove box. The relays re-spond to inputs from the power lock switches and the
2. 8P - 2 POWER LOCKS ZJ DIAGNOSIS As a preliminary system diagnosis, note system op- (11) Hold left switch in LOCK position. Measureeration while you actuate both the Lock and Unlock voltage at lock relay terminal 1. Meter should readfunctions with the power lock switches and the key- battery voltage. If OK, go to next step. If not OK, re-less entry transmitter. Then, proceed as follows: place faulty lock relay.• If system fails to function with either the switches (12) Hold left switch in UNLOCK position. Mea-or the transmitter, see Power Lock System diagnosis. sure voltage at unlock relay terminal 1. Meter should• If system functions with both switches, but not the read battery voltage. If OK, check circuit to door locktransmitter, see Keyless Entry Transmitter diagnosis. motor and see Power Lock Motor. If not OK, replace• If system functions with transmitter, but not with faulty unlock relay.one or both switches, see Power Lock System diagno- (13) Repeat steps 7 through 12 for right door locksis. switch.• If one lock fails to operate with the switches ortransmitter, see Power Lock Motor diagnosis.POWER LOCK SYSTEM (1) Inspect fuses 8 and 14 in fuseblock module. Re-place if necessary. If OK, measure voltage at batteryside of fuse. There should be 12 volts. If not OK, re-pair open from Power Distribution Center. (2) Remove door switch(es) and measure voltage atterminal 4. Meter should read battery voltage. If OK,go to next step. If not OK, repair open to fuse 8 infuseblock module. (3) Remove glove box bottom to access the relaycenter. (4) Measure resistance between lock and unlock re-lay terminal 4 and ground. Also measure resistanceat terminal 5 of the unlock relay. Meter should read Fig. 1 Door Lock/Unlock Relayszero ohms. If OK, go to next step. If not OK, repaircircuit to ground. POWER LOCK MOTOR (5) Measure voltage at terminal 2 of both the lock (1) Once it is determined which lock motor is inop-and unlock relays. Meter should read battery voltage. erative, that motor can be tested. Disconnect the wireIf OK, go to next step. If not OK, repair circuit to connector at the motor. Apply 12 volts to the motorfuse 14 in fuseblock module. terminals to check its operation in one direction. Re- (6) Measure resistance at terminal 5 of the lock re- verse the polarity to check the operation in the otherlay. Meter should read zero ohms with left front door direction. If OK, repair circuits to power lock/unlockclosed. If OK, go to next step. If not OK, repair cir- relays as required. If not OK, replace the motor.cuit to chime module and/or see Group 8U - Chime/ (2) If all lock motors are inoperative, the problemBuzzer Warning Systems for further diagnosis. may be caused by one shorted motor. Disconnecting a (7) Hold left switch in LOCK position. Measure shorted motor will allow the good motors to operate.voltage at lock switch terminal 5. Meter should readbattery voltage. If OK, go to next step. If not OK, re- Disconnect each motor connector, one at a time, andplace faulty switch. re-check both lock and unlock functions while operat- (8) Hold left switch in UNLOCK position. Measure ing the door lock switch. If disconnecting one motorvoltage at lock switch terminal 1. Meter should read causes the other motors to become functional, gobattery voltage. If OK, go to next step. If not OK, re- back to step 1 to test the disconnected motor.place faulty switch. (9) Hold left switch in LOCK position. Measure KEYLESS ENTRY TRANSMITTERvoltage at lock relay terminal 3. Meter should read (1) Depress either transmitter button and notebattery voltage. If OK, go to next step. If not OK, re- whether red Light-Emitting Diode (LED) on trans-pair circuit to left switch. mitter case lights. If OK, go to next step. If not OK, (10) Hold left switch in UNLOCK position. Mea- replace batteries as described under Keyless Entrysure voltage at unlock relay terminal 3. Meter should Transmitter in Service Procedures. Test transmitterread battery voltage. If OK, go to next step. If not operation. If OK, discard faulty batteries. If not OK,OK, repair circuit to left switch. go to next step.
3. ZJ POWER LOCKS 8P - 3 (2) Perform transmitter program procedure with (4) Check resistance between connector cavity forsuspect transmitter and another known good trans- module terminal 10 and a good ground. Meter shouldmitter, as described in Service Procedures. Test oper- read zero ohms. If OK, go to next step. If not OK, re-ation with both transmitters. If both transmitters fail pair circuit to ground.to operate power locks, see Keyless Entry Module di- (5) Probe connector cavity for module terminal 1agnosis. If known good transmitter operates power and check for battery voltage. If OK, go to next step.locks and suspect transmitter does not, replace faulty If not OK, repair circuit to fuse 8 as required.transmitter. Be certain to perform transmitter pro- (6) Install a jumper wire from connector cavity forgram procedure again when replacing faulty trans- module terminal 1 to connector cavity for module ter-mitter and to erase test transmitter access code from minal 3. Doors should lock. If OK, go to step 8. If notkeyless entry module. OK, go to next step. (7) Check for continuity between connector cavityKEYLESS ENTRY MODULE for module terminal 3 and lock relay terminal 3 (86). (1) Check fuse 8 in fuseblock module. If OK, go to There should be continuity. If OK, replace lock relay.next step. If not OK, replace fuse. If not OK, repair circuit as required. (2) Check for battery voltage at fuse 8. If OK, go tonext step. If not OK, repair circuit from power distri- (8) Install a jumper wire from connector cavity forbution center. module terminal 1 to connector cavity for module ter- (3) Access keyless entry module connectors as de- minal 4. Doors should unlock. If OK, replace module.scribed in Keyless Entry Module Remove/Install. Un- If not OK, go to next step.plug connector and check connector and receptacle in (9) Check for continuity between connector cavitymodule for loose, corroded, or damaged terminals and for module terminal 4 and unlock relay terminal 3pins. If OK, go to next step. If not OK, repair as re- (86). There should be continuity. If OK, replace un-quired. lock relay. If not OK, repair circuit as required.
4. 8P - 4 POWER LOCKS ZJ SERVICE PROCEDURESKEYLESS ENTRY TRANSMITTER programmed into the module. Within 20 seconds of To replace transmitter batteries, separate transmit- the previous transmitter programming, move the me-ter case by prying gently with a trim stick or other chanical door lock lever to the LOCK position. Aimwide flat-bladed tool at center seam (Fig. 2). Case another transmitter at the receiver dome and presssnaps open and shut. Replace with CR1616 3-volt the LOCK button for at least 5 seconds. The doorbatteries or equivalent (Fig. 3). lock will cycle again. (6) To lock the programmed codes into the module, the ignition switch must be turned OFF and back ON within 20 seconds after programming the last transmitter’s code. At that time, all previous codes are erased from the module. POWER LOCK SWITCH REMOVE/INSTALL (1) Remove screw at top of trim panel near mirror (Fig. 4). Fig. 2 Separate Transmitter Halves Fig. 4 Front Door Trim Panel Remove (2) Remove screw from demister opening at front of door. (3) Remove screw and door handle cover. (4) Remove screw from under armrest. (5) Remove screw from bottom of hand hold cup in armrest. Fig. 3 Battery Install CAUTION: The wiring harness to the door switchesTRANSMITTER PROGRAMMING PROCEDURE is just long enough to allow installation. If trim (1) Open the driver’s door of the vehicle. Leave it panel is pulled off by hand the switch may beopen through the programming procedure. pulled apart. Use a door clip tool to prevent damag- (2) Move the mechanical door lock lever to the ing the switches.LOCK position. (3) Turn the ignition switch to the ON position. (6) Remove the trim panel with a wide, flat-bladed (4) Within 20 seconds, aim a transmitter at the tool (Fig. 5).keyless entry module receiver dome and press the To aid in removal of the trim panel, start atLOCK button for at least 5 seconds. Once the module the bottom of the panel.accepts the programming code, the driver’s door will (7) Unplug electrical connector from switch.unlock. (8) Remove switch from door panel. (5) Once the first transmitter has been pro- (9) Reverse removal procedures to install.grammed, additional transmitters (up to 4) may be
5. ZJ POWER LOCKS 8P - 5 Fig. 5 Trim Panel Remove - TypicalPOWER LOCK MOTOR REMOVE/INSTALLFRONT DOORS (1) Remove front door trim panel as described inPower Lock Switch Remove/Install. (2) Remove 1 bolt holding bottom of window trackto door (Fig. 6). Fig. 7 Lock Actuator Motor - Front Door Fig. 6 Window Track Attaching Bolts - Front Door (3) Disconnect 4 linkage rods from their clips (Fig.7). (4) Unplug wire harness connector from lock actua-tor motor. Fig. 8 Latch Remove/Install - Typical (5) Remove 3 torx head screws retaining the latch (10) Operate outside latch handle button several(Fig. 8). times to release any restriction or tension caused by (6) Place the lock actuator motor, latch and remote improper adjustment.control rods in the door. (11) Tighten latch adjustment screw to 3 N⅐m (30 (7) Attach the lock actuator motor to the door in. lbs.).panel with 3 torx head screws. Tighten screws to 11 (12) Test outside latch handle button and lock cyl-N⅐m (95 in. lbs.). inder for proper operation. (8) Install 4 linkage rods. (13) Using 3M 08044 or 3M 08041 adhesive/seal- (9) Insert a 5/32-inch hex wrench through access ant, install the plastic inner door water shield.hole into latch adjustment screw (Fig. 8). Loosenscrew.
6. 8P - 6 POWER LOCKS ZJ (14) Reverse remaining removal procedures to com- (6) Disconnect 4 linkage rods from their clips (Fig.plete installation. 11).REAR DOORS (1) Remove screw and door handle cover (Fig. 9). Fig. 9 Rear Door Trim Panel Attachment (2) Remove screw from under armrest. (3) Remove screw from bottom of hand hold inarmrest.CAUTION: The wiring harness to the door switchesis just long enough to allow installation. If trimpanel is pulled off by hand the switch may bepulled apart. Use a door clip tool to prevent damag- Fig. 11 Lock Actuator Motor - Rear Dooring the switches. (7) Unplug wire harness connector from lock actua- (4) Remove the trim panel with a wide, flat-bladed tor motor.tool (Fig. 5). (8) Remove 3 torx head screws retaining the latch To aid in removal of the trim panel, start at (Fig. 12).the bottom of the panel. (5) Remove 1 bolt holding bottom of window trackto door (Fig. 10). Fig. 12 Latch Remove/Install - Typical (9) Place the lock actuator motor, latch and remote control rods in the door. Fig. 10 Window Track Attaching Bolts - Rear Door
7. ZJ POWER LOCKS 8P - 7 (10) Attach the lock actuator motor to the doorpanel with 3 torx head screws. Tighten screws to 11N⅐m (95 in. lbs.). (11) Install 4 linkage rods. (12) Insert a 5/32-inch hex wrench through accesshole into latch adjustment screw (Fig. 12). Loosenscrew. (13) Operate outside latch handle button severaltimes to release any restriction or tension caused byimproper adjustment. (14) Tighten latch adjustment screw to 3 N⅐m (30in. lbs.). (15) Test outside latch handle button for proper op-eration. (16) Using 3M 08044 or 3M 08041 adhesive/seal-ant, install the plastic inner door water shield. (17) Reverse remaining removal procedures to com- Fig. 14 Lock Actuator Motor Linkage Clipplete installation.LIFTGATE (1) Remove 5 screws holding liftgate interior trimpanel. (2) Remove the trim panel with a wide, flat-bladedtool (Fig. 13). Fig. 15 Liftgate Lock Actuator Motor Remove/Install Fig. 13 Liftgate Trim Panel Remove To aid in removal of the trim panel, start atthe bottom of the panel. (3) Disconnect the lock actuator motor linkage clipat the handle (Fig. 14). (4) Remove 2 lock actuator motor retaining screws(Fig. 15). (5) Remove the lock actuator motor. (6) Reverse the removal procedures to install.Tighten the lock actuator motor retaining screws to 3N⅐m (28 in. lbs.).
8. 8P - 8 POWER LOCKS ZJKEYLESS ENTRY MODULE REMOVE/INSTALLWITH OVERHEAD CONSOLE AND WITHOUTSUNROOF (1) Remove console forward mounting screw (Fig.16). Fig. 18 Rear Overhead Console Panel Remove (7) Remove the screw and the printed circuit board can be removed (Fig. 19). Fig. 16 Remove/Install Overhead Console (2) Unplug trip computer harness connector. (3) Slide console forward until the console retain- Fig. 19 Keyless Entry Receiver Remove/Installers detach from the rear mounting bracket. (8) Reverse removal procedures to install. (4) Unplug keyless entry receiver harness connec-tor (Fig. 17). Fig. 17 Keyless Entry Receiver Harness Connector (5) Remove 6 screws holding rear half of console(Fig. 18). (6) Release 4 clips and separate cover panel outfrom console.
9. ZJ POWER LOCKS 8P - 9WITH SUNROOF OR WITHOUT OVERHEADCONSOLE (1) Remove dome lamp lens, then remove 2 screwsattaching the dome lamp housing to the roof (Fig.20). Fig. 21 Keyless Entry Receiver Remove/Install Fig. 20 Remove/Install Dome Lamp Housing (2) Push the housing toward the front of the vehi-cle to disengage retainers. (3) Unplug the harness connectors. (4) Release the receiver circuit board connectorfrom its mounting location (Fig. 21). (5) Remove circuit board from housing by releasing Fig. 22 Relay Center Cover4 retainer clips (Fig. 21). (6) Reverse removal procedures to install.POWER LOCK/UNLOCK RELAY REMOVE/INSTALL (1) Open glove box and remove 3 screws holdingrelay center cover (Fig. 22). (2) Remove lock or unlock relay as required (Fig.23). (3) To install, align relay terminals with cavities inrelay center and push relay into place. (4) Re-install relay center cover. Fig. 23 Power Lock/Unlock Relays