DESCRIPTION & OPERATION
The Memory Seat/Mirror (MSM) module is located under driver seat. The MSM module provides driver with power adjustable seat, recliner and power side mirror positioning controls that remember stored positions and can resume these positions upon command. MSM module monitors switch inputs and operates appropriate component motor. Component motors have position sensing potentiometers for memory recall. MSM module stores this position information after a valid input sequence. See SETTING MEMORY POSITIONS. Memory system can be activated using Remote Keyless Entry (RKE) transmitter. See USING RKE SYSTEM.
Setting Memory Positions
MSM module allows storage of 2 different mirror and seat presets. Use mirror and seat switches to attain mirror and seat positions desired. Press and release "S" button located below driver inside door handle. Press and release "1" or "2" button within 5 seconds of releasing "S" button to store positions in memory. Do not press any other seat or mirror buttons for 10 seconds. A 2nd set of positions can be stored by using other numbered button. Every time the "S" button is pressed followed by a numbered button, the old memory position is erased and replaced by existing positions. Stored positions can be activated by pressing numbered button while vehicle is in Park.
Using RKE System
To program RKE transmitter, seat and mirror position must be reset. See SETTING MEMORY POSITIONS. After numbered button on driver door panel is pressed, press and release Lock button on RKE transmitter. After the RKE transmitter is programed, unlocking car using RKE transmitter will return seat and mirror to preset positions.
TESTING
| CAUTION | When battery is disconnected, vehicle computer and memory systems may lose memory data. Driveability problems may exist until computer systems have completed a relearn cycle. See COMPUTER RELEARN PROCEDURES article in the GENERAL INFORMATION section before disconnecting battery. |
MEMORY SELECTOR SWITCH
Remove memory selector switch assembly from driver door panel. See MEMORY SWITCHES under REMOVAL & INSTALLATION. Using ohmmeter, test continuity between appropriate switch terminals. (Scheme 1) If continuity is not as specified, replace memory selector switch assembly. See MEMORY SELECTOR SWITCH ASSEMBLY TEST table.
| Button Depressed (1) | Continuity Between Pins No. |
|---|---|
| "1" | 6 & 3 |
| "2" | 4 & 3 |
| "S" | 5 & 3 |
| (1) Without buttons depressed, all circuits are open. No continuity. | |
| (1) | Without buttons depressed, all circuits are open. No continuity. |
MEMORY SELECTOR SWITCH ASSEMBLY TEST
Scheme 1
Mode 1
Diagnostic mode 1 clears soft limits and sets memory switches to predetermined values. To activate, press and hold "S" and "1" buttons for 5 seconds. Mode 1 is exited at completion of tasks or when RKE input to MSM module is grounded. The RKE input is grounded by shifting transmission out of Park. Memory "1" button will be set to horizontal rearward, front down, rear down and recliner rearward positions. Memory "2" button will be set to horizontal forward, front up, rear up and recliner forward positions.
Mode 2
Diagnostic mode 2 shows if seat/mirror motors and position sensors are connected properly. To activate, press and hold "S" and "2" buttons for 5 seconds. Mode 2 is exited after 5 seconds of switch inactivity or when RKE input to MSM module is grounded. The RKE input is grounded by shifting transmission out of Park. Mode 2 will
- Adjust seat and mirror motors to midpoint.
- To test switch input and motor output, seat or mirror motors will respond to single axis switch requests.
- When switch is released, motors will automatically return to original position. If sensor for motor is out of range the motor will not return to original position. This test checks integrity of sensor and motor outputs. For circuit descriptions see appropriate CONNECTOR TERMINAL IDENTIFICATION table. (Scheme 2)- (Scheme 4).
Scheme 2
| Terminal No. | Wire Color | Description |
|---|---|---|
| 1 | Red/Lt. Blue | Seat B+ Horizontal Rear |
| 2 | Yellow/Dk. Blue | Seat B+ Horizontal Front |
| 3 | Yellow/White | Seat B+ Rear Riser Up |
| 4 | Gray/Lt. Blue | Recliner B+ Seat Back Front |
| 5 | Yellow/Lt. Green | Seat B+ Front Riser Up |
| 6 | Red/White | Seat B+ Rear Riser Down |
| 7 | Black | Module Ground |
| 8 | Red | Battery Feed To Module |
| 9 | Gray/White | Recliner B+ Seat Back Rear |
| 10 | Red/Lt. Green | Seat B+ Front Riser Down |
MSM MODULE 10-PIN CONNECTOR TERMINAL IDENTIFICATION
Scheme 3
| Terminal No. | Wire Color | Description |
|---|---|---|
| 1 | Red/Lt. Green | Seat Horizontal Front Riser Down Switch Input |
| 2 | Red/White | Seat Rear Riser Down Switch Input |
| 3 | Red/Lt. Blue | Seat Horizontal Rear Switch Input |
| 4 | Gray/White | Recliner Rear Switch Input |
| 7 | Lt. Blue/Red | Seat Rear Position Sense (UP/Down) |
| 8 | Brown | Seat Front Position Sense (UP/Down) |
| 10 | Brown/Red | Seat & Recliner Position Sense Ground |
| 11 | Red | Seat & Recliner Switch PTC Resistive Feed |
| 12 | Yellow/Lt. Green | Seat Front Riser Up Switch Input |
| 13 | Yellow/White | Seat Rear Riser Up Switch Input |
| 14 | Yellow/Lt Blue | Seat Horizontal Front Switch Input |
| 15 | Gray/Lt. Blue | Recliner Front Switch Input |
| 17 | Lt. Blue | Recliner Position Sense (For/Aft) |
| 18 | Violet/Red | Seat Horizontal Position Sense (For/Aft) |
| 20 | Brown/Red | Seat & Recliner Position Sense + Feed |
MSM MODULE 21-PIN CONNECTOR TERMINAL IDENTIFICATION
Scheme 4
| Terminal No. | Wire Color | Description |
|---|---|---|
| 1 | White/Red | Left Mirror Rheostat Sense Ground |
| 2 | Yellow/Orange | Left Mirror Rheostat Sense Vertical |
| 3 | Dk. Blue/Yellow | Left Mirror Rheostat Sense Horizontal |
| 8 | Pink/Black | Memory Set Switch Input |
| 10 | Yellow/Pink | Left Common Mirror Output |
| 11 | Yellow | Left Vertical Mirror Output |
| 12 | Dk Blue/White | Left Horizontal Mirror Output |
| 13 | White/Black | Right Mirror Rheostat Sense Ground |
| 14 | Yellow/Red | Right Mirror Rheostat Sense Vertical |
| 15 | Dk. Green/Red | Right Mirror Rheostat Sense Horizontal |
| 16 | Pink | Battery Feed For Wake-Ups & Recalls |
| 19 | Lt Green/Red | RKE Data Link Input |
| 20 | Pink/Red | Memory Switch "1" Input |
| 21 | Pink/White | Memory Switch "2" Input |
| 23 | White | Right Common Mirror Output |
| 24 | Yellow/Black | Right Vertical Mirror Output |
| 25 | Dk Blue | Right Horizontal Mirror Output |
MSM MODULE 25-PIN CONNECTOR TERMINAL IDENTIFICATION
CHECKING POWER & GROUNDS
- Power seats and mirrors receive power through fuse No. 2, a 40-amp maxi-fuse located in Power Distribution Center (PDC). PDC is located in engine compartment on left inner fenderwell. If power seats, mirrors, locks, rear blower and fog lamps are all inoperative check maxi-fuse and replace as necessary.
- If new fuse blows immediately, repair short to ground in one of the listed circuits. See the SYSTEM WIRING DIAGRAMS article in the WIRING DIAGRAMS section.
- If power seats are inoperative with a good maxi-fuse, check 30-amp circuit breaker located in driver's seat harness 10 inches from Black 4-pin connector.
- The power circuit is Red/White wire. Leaving 30-amp circuit breaker, 2 Red wires supply system power to passenger power seat switch and MSM module.
- If power locks, rear blower and fog lamps are all operating and both seats are inoperative, repair open in Red wire or defective 30-amp circuit breaker.
- Ensure Black ground wire between left cowl ground block and driver power seat switch terminal No. 1 and between left cowl ground block and MSM module terminal No. 7 have continuity.
- If passenger power seat is operational and driver power seat is not, check continuity of Red wire between 30-amp circuit breaker and MSM module 10-pin connector terminal No. 8. (Scheme 2) Repair as necessary.
- If driver power seat remains inoperative, using DVOM, check for voltage at MSM module 21-pin connector terminal No. 11 and Driver power seat switch terminal No. 5. (Scheme 3) This is a low current battery voltage circuit and will not light a test light. If voltage is not present, replace MSM module or repair open Red wire as necessary.
MSM Module Does Not Make Relay Click Sound When Any Power Seat Switch Input Is Selected
- Check power and ground circuits. See «CHECKING POWER & GROUNDS»(/chrysler/town-country/iii-1995-2000/remont/memory-modules/#memory-systems__checking-power-grounds) under TESTING. Ensure connectors are firmly engaged into MSM module.
- To wake up MSM module, shift vehicle into any gear. Position sense voltage can be checked at MSM module 21-pin and 25-pin connectors. See «MSM MODULE 21-PIN CONNECTOR TERMINAL IDENTIFICATION»(/chrysler/town-country/iii-1995-2000/remont/memory-modules/#memory-systems) table and «MSM MODULE 25-PIN CONNECTOR TERMINAL IDENTIFICATION»(/chrysler/town-country/iii-1995-2000/remont/memory-modules/#memory-systems) table. Ensure driver power seat switch connector is seated firmly on inside and outside of shield.
- Using DVOM, check driver power seat switch for output voltage at appropriate terminals. See «WIRING DIAGRAMS»(/chrysler/town-country/iii-1995-2000/remont/memory-modules/#memory-systems). Check for driver power seat switch output voltage at appropriate MSM module terminals. See «MSM MODULE 21-PIN CONNECTOR TERMINAL IDENTIFICATION»(/chrysler/town-country/iii-1995-2000/remont/memory-modules/#memory-systems) table and test terminals No. 1-4 and 12-15. (Scheme 3) If voltage is not present at any terminal of MSM module, repair or replace seat wiring harness. If voltage is present at all terminals of MSM module, replace MSM module.
MSM Module Does Not Make Relay Click Sound When Specific Power Seat Switch Input Is Selected
Check continuity of circuit that does not click between MSM module and driver power seat switch. See WIRING DIAGRAMS . See MSM MODULE 21-PIN CONNECTOR TERMINAL IDENTIFICATION table. If voltage is not present at appropriate terminal of MSM module, repair or replace seat wiring harness. If voltage is present at appropriate terminal of MSM module, replace MSM module.
MSM Module Provides Relay Click Sound When Power Seat Switch Input Is Selected But No Reaction From Appropriate Motor
Disconnect MSM module 10-pin connector. Using jumper wire, jumper battery voltage from MSM module 10-pin connector terminal No. 8 and ground. Connect second jumper wire from MSM module 10-pin connector terminal No. 7 to inoperative motor connector. (Scheme 2) Motor should operate. Reverse jumper leads at motor connector to reverse motor direction. If motor operates, replace MSM module. If motor does not operate, check continuity of wiring to motor connector from MSM module and repair as necessary. If wiring continuity is okay, replace seat track assembly. Motor assemblies are not serviceable separately.
SEAT & RECLINER POSITION SENSING
Potentiometers are built into bell end of seat motors. These potentiometers provide a voltage signal to MSM module through MSM module 21-pin connector. Voltage signal should change with motor direction. See SENSE VOLTAGE SPECIFICATIONS table.
| MSM 25-Pin Terminal No. | Position | Voltage Direction |
|---|---|---|
| 8 | Seat Track Front Up | Increase |
| 8 | Seat Track Front Down | Decrease |
| 7 | Seat Track Rear Up | Increase |
| 7 | Seat Track Rear Down | Decrease |
| 18 | Horizontal Track Forward | Increase |
| 18 | Horizontal Track Rearward | Decrease |
| 17 | Recliner Forward | Increase |
| 17 | Recliner Rearward | Decrease |
SENSE VOLTAGE SPECIFICATIONS
Using DVOM, connect negative voltmeter lead to MSM module 21-pin connector terminal No. 10 (Brown/Red wire) and positive lead to terminal No. 20 (Brown/White wire). Voltage should be 3.5-5 volts when power seat switch selection is made. If transmission is in Park, voltage will stay active for 3 seconds.
If voltage is less than 3.5 volts, disconnect MSM module 25-pin connector. If voltage is still less than 3.5 volts, disconnect position sense connectors at each seat motor. See MSM MODULE 21-PIN CONNECTOR TERMINAL IDENTIFICATION table. If voltage is still less than 3.5 volts, replace MSM module.
If voltage increases when any motor is disconnected from circuit, check seat harness for short to ground and repair or replace as necessary. If seat harness is okay, replace seat tract assembly. Motor assemblies are not serviceable separately.
REMOVAL & INSTALLATION
| CAUTION | If battery is disconnected, vehicle computer and memory systems may lose memory data. Driveability problems may exist until computer systems have completed a relearn cycle. See COMPUTER RELEARN PROCEDURES article in the GENERAL INFORMATION section before disconnecting battery. |
Insert door panel tool at front edge of memory switch bezel. Pry switch from trim panel opening. Disconnect wire connector from back of switch. To install, reverse removal procedure.
MSM module is located under driver seat. Remove fasteners holding module bracket. Remove wire connectors. (Scheme 5) Remove module from under seat. To install, reverse removal procedure.
Scheme 5
Remove seat from vehicle. Remove seat cushion pan. Remove nut holding recliner to seat back frame. Remove bolts holding seat back frame from recliner. Separate seat back from recliner. To install, transfer power recliner, wire harness and trim covers to new seat track. To complete installation, reverse removal procedure.
Memory Mirror System Wiring Diagram. Scheme 6
Memory Seat System Wiring Diagram. Scheme 7
See also:
• MEMORY SWITCHES
• CHECKING POWER & GROUNDS