Power Window Systems — 1996 Jeep Grand Cherokee ZJ Service Manual
Pages 463–469 · 7 pages · 3 words repaired
The DDM circuitry controls the output to the left front and rear door power window motors, and supplies battery feed for the power window switch on the left rear door. The PDM circuitry controls the output to the right front and rear power window motors, and supplies battery feed for the power window switch on the right rear door. When a DDM-integrated power window switch for a passenger’s side window is actuated, the DDM circuitry sends a message to the PDM on the Chrysler Collision Detection (CCD) data bus to activate the output to that power window motor(s).
The front door power window switches and their lamps cannot be repaired so, if faulty, the entire door module must be replaced. The rear door power window switches and their lamps cannot be repaired but, if faulty, only the switch unit must be replaced.
DOOR MODULE
A Driver Door Module (DDM) and a Passenger Door Module (PDM) are used on this model to control and integrate many of the vehicle’s electrical features and functions. The DDM and PDM communicate with each other, and with other vehicle modules on the Chrysler Collision Detection (CCD) data bus network.
The CCD data bus network allows the sharing of sensor information. This helps to reduce wiring harness complexity, internal controller hardware, and component sensor current loads. At the same time, this system provides increased reliability, enhanced diagnostics, and allows the addition of many new feature capabilities.
For diagnosis of the DDM, PDM, or the CCD data bus network, refer to the proper Body Diagnostic Procedures Manual.
BODY CONTROL MODULE
A Body Control Module (BCM) is used on this model to control and integrate many of the vehicle’s electrical functions and features. The BCM contains a central processing unit and interfaces with other modules in the vehicle on the Chrysler Collision Detection (CCD) data bus network.
The CCD data bus network allows the sharing of sensor information. This helps to reduce wiring harness complexity, reduce internal controller hardware, and reduce component sensor current loads. At the same time, this system provides increased reliability, enhanced diagnostics, and allows the addition of many new feature capabilities.
One of the functions and features that the BCM supports and controls, is the Power Window System. The BCM receives inputs from the ignition switch and the door ajar switches. The programming in the BCM allows it to process the information from these inputs and send ignition switch and door ajar status messages to the DDM and PDM on the CCD data bus. The DDM and PDM use this information to control the lighting of the switch lamps, and to control the power window operation after ignition off feature.
The BCM is mounted under the left end of the instrument panel, behind the instrument panel support armature and below the left switch pod. Refer to Group 8E - Instrument Panel Systems for removal and installation procedures. For diagnosis of the BCM or the CCD data bus, refer to the proper Body Diagnostic Procedures Manual. The BCM can only be serviced by an authorized repair station. Refer to the Warranty Policies and Procedures Manual for a listing of authorized repair stations.
POWER WINDOW MOTOR
A permanent magnet reversible motor moves the window regulator through an integral gearbox mechanism. A positive and negative battery connection to the two motor terminals will cause the motor to rotate in one direction. Reversing current through these same two connections will cause the motor to rotate in the opposite direction. In addition, each power window motor is equipped with an integral self-resetting circuit breaker to protect the motor from overloads. The power window motor and gearbox assembly cannot be repaired. If faulty, the entire motor assembly must be replaced.
CIRCUIT BREAKER
An automatic resetting circuit breaker in the junction block is used to protect the power window system circuit. The circuit breaker can protect the system from a short circuit, or from an overload condition caused by an obstructed or stuck window glass or regulator. The circuit breaker cannot be repaired. If faulty, the circuit breaker must be replaced.
DIAGNOSIS AND TESTING
POWER WINDOW SYSTEM
For circuit descriptions and diagrams, refer to 8W-60 - Power Windows in Group 8W - Wiring Diagrams.
ALL WINDOWS INOPERATIVE
(1) Check the circuit breaker in the junction block, as described in this group. If OK, go to Step 2. If not OK, replace the faulty circuit breaker.
(2) Remove the left and right front door trim panels. Check the 12-way door module wiring connectors to see that they are fully seated in the door module receptacles. If OK, go to Step 3. If not OK, install the connectors properly.
(3) Unplug the 12-way door module connectors. Check for continuity between the ground circuit cavity of each module connector and a good ground. If OK, go to Step 4. If not OK, repair the open circuit to ground as required.
(4) Check for battery voltage at the fused B(+) circuit cavity of each module connector. If OK, use a DRB scan tool and the proper Body Diagnostic Procedures Manual to diagnose the door modules and the CCD data bus. If not OK, repair the open circuit to the junction block as required.
ONE WINDOW INOPERATIVE
The window glass must be free to slide up and down for the power window motor to function properly. If the glass is not free to move up and down, the motor will overload and trip the circuit breaker. To determine if the glass is free, disconnect the regulator plate from the glass. Then slide the window up and down by hand.
There is an alternate method to check if the glass is free. Position the glass between the up and down stops. Then, shake the glass in the door. Check that the glass can be moved slightly from side to side, front to rear, and up and down. Then check that the glass is not bound tight in the tracks. If the glass is free, proceed to the Door Module diagnosis in this group. If the glass is not free, refer to Group 23 - Body Components for window glass service and adjustment procedures.
CIRCUIT BREAKER
For circuit descriptions and diagrams, refer to 8W-60 - Power Windows in Group 8W - Wiring Diagrams.
(1) Locate the correct circuit breaker in the junction block. Pull out the circuit breaker slightly, but be sure that the terminals still contact the terminals in the junction block.
(2) Connect the negative lead of a 12-volt DC voltmeter to a good ground.
(3) With the voltmeter positive lead, check both terminals of the circuit breaker for battery voltage.
If only one terminal has battery voltage, the circuit breaker is faulty and must be replaced. If neither terminal has battery voltage, repair the open circuit from the power distribution center as required. If the circuit breaker checks OK, but no power windows operate, see the diagnosis for Power Window System.
DOOR MODULE
If the problem being diagnosed is a rear door window that doesn’t operate from the rear door switch, but does operate from the master switch on the driver’s door, go to the diagnosis for Power Window Switch in this group. If the problem is a passenger side front or rear window that operates from the switch on that door, but does not operate from the master switch on the driver’s door, use a DRB scan tool and the proper Body Diagnostic Procedures Manual to diagnose the circuitry of the door modules and the CCD data bus.
NOTE: The following tests may not prove conclusive in the diagnosis of this component. The most reliable, efficient, and accurate means to diagnose this system involves the use of a DRB scan tool and the proper Body Diagnostic Procedures Manual.
For circuit descriptions and diagrams, refer to 8W-60 - Power Windows in Group 8W - Wiring Diagrams.
(1) Disconnect and isolate the battery negative cable. Remove the front door trim panel as described in this group. Go to Step 2.
(2) Check the 12-way door module wiring connector to see that it is fully seated in the door module receptacle. If OK, go to Step 3. If not OK, install the connector properly.
(3) Unplug the 12-way connector from the door module. Check for continuity between the ground circuit cavity of the door module connector and a good ground. There should be continuity. If OK, go to Step 4. If not OK, repair the open circuit as required. (4) Connect the battery negative cable. Check for battery voltage at the fused B(+) circuit cavity of the connector. If OK, go to Step 5. If not OK, repair the open circuit as required.
(5) If the inoperative window is on a front door, go to Step 6. If the inoperative window is on a rear door go to Step 9.
(6) Disconnect and isolate the battery negative cable. Unplug the inoperative power window motor connector. Check for continuity between the front window driver up circuit cavity of the door module connector and a good ground. Repeat the check for the front window driver down circuit cavity. In each case there should be no continuity. If OK, go to Step 7. If not OK, repair the short circuit as required. (7) Check for continuity between the front window driver up circuit cavities of the door module connector and the power window motor connector. Repeat the check for the front window driver down circuit cavities. In each case there should be continuity. If OK, go to Step 8. If not OK, repair the open circuit as required.
(8) Plug the 12-way connector back into the door module. Connect the battery negative cable. Connect the probes of a reversible DC digital voltmeter to the door module side of the power window motor connector. Observe the voltmeter while actuating the switch in the up and down directions. There should be battery voltage for as long as the switch is held in both the up and down positions, and no voltage in the neutral position. If OK, see the diagnosis for Power
Window Motors. If not OK, replace the faulty door module.
(9) Disconnect and isolate the battery negative cable. Remove the rear door trim panel as described in this group. Check the rear door power window switch continuity as described in this group. If OK, go to Step 10. If not OK, replace the faulty switch.
(10) Connect the wiring to the rear door power window switch. Unplug the inoperative power window motor connector. Check for continuity between the rear window driver up circuit cavity of the door module connector and a good ground. Repeat the check for the rear window driver down circuit cavity. In each case there should be no continuity. If OK, go to Step 11. If not OK, repair the short circuit as required.
(11) Check for continuity between the rear window driver up circuit cavities of the door module connector and the power window motor connector. Repeat the check for the rear window driver down circuit cavities. In each case there should be continuity. If OK, go to Step 12. If not OK, repair the open circuit as required.
NOTE: The door module feeds battery voltage to both terminals of the rear door power window motors when the window lock switch is in the Unlock position. The door module feeds ground to both terminals of the rear door power window motor when the window lock switch is in the Lock position.
(12) Plug the 12-way connector back into the door module. Connect the battery negative cable. Check for battery voltage at each cavity of the switch side of the power window motor connector. Each cavity should have battery voltage in the neutral position. Each cavity should also have battery voltage in one other switch position, either up or down, and zero volts with the switch in the opposite position. If OK, go to the Power Window Motor diagnosis in this group. If not OK, replace the faulty door module.
POWER WINDOW SWITCH
This diagnosis is for the rear door power window switches. The front door power window switches are integral to the door modules. For diagnosis of the front door power window switches, refer to Door Module in this group. For circuit descriptions and diagrams, refer to 8W-60 - Power Windows in Group 8W - Wiring Diagrams. (1) Disconnect and isolate the battery negative cable.
(2) Remove the switch from the door trim panel as described in this group. Unplug the wiring connector from the switch.
(3) Check the switch continuity in each position, as shown in the chart (Fig. 1). If OK, see the Power Window Motor diagnosis in this group. If not OK, replace the faulty switch.
POWER WINDOW MOTOR
For circuit descriptions and diagrams, refer to 8W-60 - Power Windows in Group 8W - Wiring Diagrams. Before you proceed with this diagnosis, confirm proper switch operation. See the Door Module and/or Power Window Switch diagnosis in this group.
(1) Remove the door trim panel as described in this group.
(2) Disconnect the power window motor connector. Apply 12 volts across the motor terminals to check its operation in one direction. Reverse the connections across the motor terminals to check the operation in the other direction. Remember, if the window is in the full up or full down position, the motor will not operate in that direction by design. If OK, repair the circuits from the motor to the switch as required. If not OK, replace the faulty motor.
(3) If the motor operates in both directions, check the window’s operation through its complete up and down travel. If not OK, refer to Group 23 - Body Components to check the window glass, tracks, and regulator for sticking, binding, or improper adjustment.
REMOVAL AND INSTALLATION
DOOR MODULE
(1) Disconnect and isolate the battery negative cable.
(2) Remove the bezel near the inside door latch release handle by inserting a straight-bladed screwdriver in the notched end and prying gently upwards.
(3) Remove the door trim panel mounting screw located in the bezel opening near the inside door latch release handle (Fig. 2).
(4) Remove the trim cap and screw near the rear of the door armrest.
(5) Remove the trim cap and screw at the upper front corner of the trim panel.
(6) Remove the screw located above the front door speaker grille.
(7) Using a wide flat-bladed tool such as a trim stick, pry the trim panel away from the door around the perimeter and remove the trim panel.
NOTE: To aid in the removal of the trim panel, start at the bottom of the panel.
(8) Unplug the wiring connectors from the door module and the door courtesy lamp, if equipped.
(9) Remove the five screws securing the door module to the door trim panel (Fig. 3).
(10) Remove the door module from the trim panel. (11) Reverse the removal procedures to install.
POWER WINDOW SWITCH
(1) Disconnect and isolate the battery negative cable.
(2) Remove the rear door trim panel bezel near the inside door latch release handle by inserting a straight-bladed screwdriver in the notched end and prying gently upwards.
(3) Remove the door trim panel mounting screw located in the bezel opening near the inside door latch release handle (Fig. 4).
(4) Remove the trim cap and screw near the rear of the door armrest.
(5) Using a wide flat-bladed tool such as a trim stick, pry the trim panel away from the door around the perimeter and remove the trim panel.
NOTE: To aid in the removal of the trim panel, start at the bottom of the panel.
(6) Unplug the wiring connector from the door power window switch.
(7) Unsnap the switch from the receptacle in the trim panel (Fig. 5).
Install
(8) Reverse the removal procedures to install.
POWER WINDOW MOTOR
FRONT DOOR
(1) Remove the front door trim panel as described in Door Module in this group.
(2) Remove the watershield from the inner door panel.
(3) Loosen the two nuts securing the door glass to the window regulator lift plate (Fig. 6).
(4) Slide the door glass rearward to remove it from the nuts.
(5) Pull the door glass to the full up position and tape the glass to the upper door window frame.
(6) Unplug the wire harness connector from the power window motor.
(7) Remove the four screws securing the window regulator to the inner door panel (Fig. 7).
(8) Loosen the last two screws securing the regulator to the inner door panel.
(9) Remove the window regulator assembly from inside the door.
(10) To install, place the window regulator inside the door and slide the two loose screws into the slotted holes in the door inner panel.
(11) Install the remaining regulator mounting screws and tighten to 12 N·m (105 in. lbs.).
(12) Remove the tape securing the glass to the upper door window frame and lower the glass. Move the glass as far rearward into the channel as possible and push down. Tighten the two loose window regulator screws to 12 N·m (105 in. lbs.).
(13) Attach the door glass by sliding the two nuts into the slotted holes on the regulator lift plate. Tighten the nuts to 12 N·m (105 in. lbs.).
(14) Connect the wire harness to the power window motor.
(15) Use an adhesive/sealant to install the plastic watershield to the door inner panel.
(16) Reverse the remaining removal procedures to complete the installation.
REAR DOOR
(1) Remove the rear door trim panel as described in Power Window Switch in this group.
(2) Remove the watershield from the inner door panel.
(3) Loosen the two nuts securing the door glass to the window regulator lift plate (Fig. 8).
(4) Slide the door glass forward to remove it from the nuts.
(5) Pull the door glass to the full up position and tape the glass to the upper door window frame.
(6) Unplug the wire harness connector from the power window motor.
(7) Remove the four screws securing the window regulator to the inner door panel (Fig. 9).
(8) Loosen the last two screws securing the regulator to the inner door panel.
(9) Remove the window regulator assembly from inside the door.
(10) To install, place the window regulator inside the door and slide the two loose screws into the slotted holes in the door inner panel.
(11) Install the remaining regulator mounting screws and tighten to 12 N·m (105 in. lbs.).
(12) Remove the tape securing the glass to the upper door window frame and lower the glass. Move the glass as far rearward into the channel as possible and push down. Tighten the two loose window regulator screws to 12 N·m (105 in. lbs.).
(13) Attach the door glass by sliding the two nuts into the slotted holes on the regulator lift plate. Tighten the nuts to 12 N·m (105 in. lbs.).
(14) Connect the wire harness to the power window motor.
(15) Use an adhesive/sealant to install the plastic watershield to the door inner panel.
(16) Reverse the remaining removal procedures to complete the installation.