Memory System Cadillac Eldorado X

DESCRIPTION

Note. For additional information about power seats, see SEATS - POWER article. For additional information about power mirrors, see MIRRORS - POWER article.

The memory seat and mirror system allows the driver's seat to be set in 4 preset positions: MEMORY 1, MEMORY 2, EXIT 1 and EXIT 2. The Memory Seat Module (MSM) controls movement of 3 seat position motors, 2 lumbar support motors and one recline motor. The Memory Mirror Module (MMM) controls movement of 2 left mirror motors and 2 right mirror motors. All motors have a position sensor, and work independently of each other.

On Concours and DeVille, MMM receives manual seat operation inputs from left seat switch. MMM then sends a message over the class 2 serial data line to MSM. MSM then supplies voltage to appropriate seat motors.

On Eldorado and Seville, MSM receives manual seat operation inputs directly from the left seat switch. MSM then supplies voltage to appropriate seat motors.

POWER MOTORS

Power seat uses 3 reversible motors that control seat position. Front and back parts of seat are operated by different motors, and can be raised and lowered independently. Third motor controls forward/backward movement. If seat switch is operated to move entire seat up and down, both height motors run simultaneously. Recline motor moves angle of seatback. Lumbar support is controlled by an up/down motor and in/out motor. Each power mirror uses an up/down motor and a left/right motor. All motors are reversible, allowing motors to operate movement in each direction.

POSITION SENSORS

Position sensors are used by MSM and MMM to store motor positions in memory and return motors to stored memory positions. Each sensor is a potentiometer, and is mounted to each motor's transmission cable. When cable rotates, resistance of potentiometer varies, and feedback voltage is monitored by MSM or MMM to determine motor position. Feedback voltages vary between 0.25 volts to 4.75 volts.

The MSM and MMM store motor positions by recording each position sensor feedback voltage. When a memorized position is requested, each motor is moved until the position sensor feedback voltage equals feedback voltage stored in memory. For Easy Exit functions, only seat position sensor feedback voltages are recorded and only seat motors operate.

MEMORY SET

MMM receives input from memory function switch. Seat, seatback, lumbar and mirror positions may be recorded for 2 drivers. When SET MEMORY button is pressed, a chime will sound. Within 5 seconds, either MEMORY-1 or MEMORY-2 button must be pressed. When these inputs are received by MMM, the feedback voltages from 4 position sensors is recorded. A single chime will sound to indicate position has been recorded. A class 2 message will also be sent to MSM. MSM then records all feedback voltages from all seat position sensors.

EASY EXIT

An EASY EXIT position may also be recorded for each memorized driver position. Move seat to comfortable exit position. Press SET MEMORY button. A chime will sound. Within 5 seconds, press EXIT button. MMM identifies memorized position for last recall or set command, and sends a class 2 message to inform MSM of appropriate set exit command to record. MSM then records feedback voltages of forward/back, rear height, front height and recline position sensors. A single chime will sound to indicate position has been recorded.

MEMORY RECALL

When MEMORY-1 or MEMORY-2 button is pressed, MMM receives input and a single chime is sounded. MMM then applies voltage to mirror motors until feedback voltage of all mirror position sensors equals the appropriate stored feedback voltages. MMM also sends a class 2 message to MSM, which then applies voltage to all seat motors until feedback voltage of all seat position sensors equals the appropriate stored feedback voltages.

When EXIT button is pressed, a single chime will sound. MMM identifies driver position of last set or recall command, and sends a class 2 message to MSM. MSM then moves forward/back, rear height, front height, and recline motors until feedback voltage of position sensors equals the appropriate stored feedback voltages.

RECALL PERSONALIZATION

When a remote keyless entry transmitter is used to unlock doors, Remote Function Actuator (RFA) sends a class 2 message to inform MMM of command and indicate which driver performed the command. When MMM receives an unlock message, 3 personalized recall options are available

1. Recall immediately upon receipt of RFA message.
2. Recall when a key-in message is received using last known driver to record or recall.
3. Do not recall upon receipt of RFA message. Only perform recall functions using memory switches.

MEMORY INHIBIT/ENABLE

MMM receive park gear and ignition inputs via class 2 messages. When ignition switch is off, memory record, memory recall, personalization recall, and exit recall functions are allowed. When ignition is on and gearshift lever is in Park, only personalization recall is deactivated and all other memory functions are allowed. When ignition is on and gearshift is out of Park, memory record is allowed, but all other memory functions are deactivated.

COMPONENT LOCATIONS

COMPONENT LOCATIONS

TROUBLE SHOOTING

Note. Trouble shooting tests are written specifically for use with GM Tech I or Tech II scan tools. Generic scan tool can be used, but may have limited functions.

DIAGNOSTIC PROCEDURE

Check for Diagnostic Trouble Codes (DTCs). See RETRIEVING DIAGNOSTIC TROUBLE CODES (DTCS) under SELF-DIAGNOSTICS. If DTCs exist, go to appropriate DIAGNOSTIC TROUBLE CODES (DTCs) under SELF-DIAGNOSTICS. If no DTCs exist, proceed to PRELIMINARY CHECKS and DIAGNOSTIC SYSTEM CHECK. After repair is complete, recheck system operation.

PRELIMINARY CHECKS

1. Check BATT fuse (10-amp) in trunk compartment fuse block. Check MIRROR fuse (10-amp) in engine compartment fuse/relay center. Check SEATS circuit breaker (30-amp) in left maxi-fuse block. Ensure ground connections are clean and tight. Check for proper installation of aftermarket electronic equipment.
2. If seat motor internal circuit breaker is tripped, remove voltage from motor to reset. Check for broken or partially broken wire inside of insulation, which could cause system malfunction but prove good in a continuity/voltage check with system disconnected. These circuits may be intermittent or resistive when loaded.

DIAGNOSTIC SYSTEM CHECK

Note. Perform this check before diagnosing symptoms.

1. Put gearshift lever in Park. Operate left seat switch in each of the following positions: Front height up, front height down, rear height up, rear height down, entire seat up, entire seat down, seat forward, seat back, recline up and recline down. Left seat should move as commanded. If seat does not move as commanded, see «LEFT SEAT DOES NOT MANUALLY MOVE IN ANY DIRECTION»(/cadillac/eldorado/x-1992-2002/remont/memory-modules/#memory-system) or LEFT SEAT DOES NOT MANUALLY MOVE IN ONE DIRECTION.
2. Operate left lumbar switch in up, down, in and out positions. Left lumbar support should move as commanded. If left lumbar support does not move as commanded, see «LEFT LUMBAR SUPPORT DOES NOT MANUALLY MOVE IN ANY DIRECTION»(/cadillac/eldorado/x-1992-2002/remont/memory-modules/#memory-system__left-lumbar-support-does-not-manually) or LEFT LUMBAR SUPPORT DOES NOT MANUALLY MOVE IN ONE DIRECTION.
3. Using mirror select switch, select left mirror. Operate left mirror switch in left, right, up and down positions. Left mirror should move as commanded. If left mirror does not move as commanded, see appropriate MIRROR DOES NOT MOVE MANUALLY symptom.
4. Using mirror select switch, select right mirror. Operate right mirror switch in left, right, up and down positions. Right mirror should move as commanded. If right mirror does not move as commanded, see appropriate MIRROR DOES NOT MOVE MANUALLY symptom.
5. Press MEMORY-1 button. A single beep should be heard. Left seat, lumbar support and both mirrors should move to programmed position for Driver No. 1. If seat or mirrors do not respond as commanded, see ONE MIRROR DOES NOT MOVE LEFT & RIGHT FOR MANUAL & RECALL FUNCTIONS, ONE MIRROR DOES NOT MOVE UP & DOWN FOR MANUAL & RECALL FUNCTIONS or MEMORY FUNCTION SWITCH INOPERATIVE.
6. Press MEMORY-2 button. A single beep should be heard. Left seat, lumbar support and both mirrors should move to programmed position for Driver No. 2. If seat or mirrors do not respond as commanded, see ONE MIRROR DOES NOT MOVE LEFT & RIGHT FOR MANUAL & RECALL FUNCTIONS, ONE MIRROR DOES NOT MOVE UP & DOWN FOR MANUAL & RECALL FUNCTIONS or MEMORY FUNCTION SWITCH INOPERATIVE.
7. Press EXIT button. A single beep should be heard. Left seat should move to exit position programmed for last memorized position. If seat or mirrors do not respond as commanded, see ONE MIRROR DOES NOT MOVE LEFT & RIGHT FOR MANUAL & RECALL FUNCTIONS, ONE MIRROR DOES NOT MOVE UP & DOWN FOR MANUAL & RECALL FUNCTIONS or MEMORY FUNCTION SWITCH INOPERATIVE.
8. Move left seat, lumbar support and both mirrors to desired position. Left seat should move as commanded. Press SET button. Within 5 seconds, press MEMORY-1 button. A single beep should be heard, and current positions for seat, lumbar support and mirrors should be stored in memory. Move left seat, lumbar support and both mirrors in all directions. Press MEMORY-1 button. Seat, lumbar support and mirrors should return to memorized position. If seat or mirrors do not respond as commanded, see ONE MIRROR DOES NOT MOVE LEFT & RIGHT FOR MANUAL & RECALL FUNCTIONS, ONE MIRROR DOES NOT MOVE UP & DOWN FOR MANUAL & RECALL FUNCTIONS or MEMORY FUNCTION SWITCH INOPERATIVE.
9. Apply parking brake. Move gearshift lever out of Park. Briefly press MEMORY-1 button. Seat and mirrors should not move. If seat and mirrors move, locate and repair problem in Brake Transaxle Shift Interlock (BTSI) system. See AUTOMATIC TRANSMISSION SERVICE article.
10. Press Driver-1 keyless entry transmitter UNLOCK button. Press Driver-2 keyless entry transmitter UNLOCK button. Recall function is capable of recalling 3 personalized options. Left seat and mirror should move to appropriate programmed option. If left seat and mirror do not function as specified, locate and repair problem in remote keyless entry system. See «KEYLESS ENTRY SYSTEM - REMOTE»(/cadillac/eldorado/x-1992-2002/remont/door-locks-anti-theft-systems/#keyless-entry-system-remote) article.

Concours & DeVille

1. If diagnostic system check was performed, go to next step. If diagnostic system check was not performed, go to «DIAGNOSTIC SYSTEM CHECK»(/cadillac/eldorado/x-1992-2002/remont/memory-modules/#memory-system__diagnostic-system-check) .
2. Disconnect MSM Light Green 6-pin connector C2. Using DVOM, check voltage between MSM harness connector C2 terminals "D" (Orange wire) and "C" (Black wire). If reading is about 12 volts, go to next step. If reading is not about 12 volts, go to step 6).
3. Disconnect MMM 32-pin connector C1. Check voltage between MMM harness connector C1 terminals E1 (Orange wire) and F1 (Black/White wire). If reading is about 12 volts, go to next step. If reading is not about 12 volts, go to step 7).
4. Disconnect left seat switch connector. Check voltage between MMM harness connector C1 terminal E1 (Orange wire) and left seat switch harness connector terminal "J" (Black wire). If reading is about 12 volts, go to next step. If reading is not about 12 volts, go to step 8).
5. Replace left seat switch. See appropriate POWER SEATS article. Perform «DIAGNOSTIC SYSTEM CHECK»(/cadillac/eldorado/x-1992-2002/remont/memory-modules/#memory-system__diagnostic-system-check) .
6. Repair open in circuit No. 850 (Black wire) between MSM and ground. Perform «DIAGNOSTIC SYSTEM CHECK»(/cadillac/eldorado/x-1992-2002/remont/memory-modules/#memory-system__diagnostic-system-check) .
7. Repair open in circuit No. 151 (Black/White wire) between MMM and ground. Perform «DIAGNOSTIC SYSTEM CHECK»(/cadillac/eldorado/x-1992-2002/remont/memory-modules/#memory-system__diagnostic-system-check) .
8. Repair open in circuit No. 50 (Black wire) between left seat switch and ground. Perform «DIAGNOSTIC SYSTEM CHECK»(/cadillac/eldorado/x-1992-2002/remont/memory-modules/#memory-system__diagnostic-system-check) .

Eldorado & Seville

1. If diagnostic system check was performed, go to next step. If diagnostic system check was not performed, go to «DIAGNOSTIC SYSTEM CHECK»(/cadillac/eldorado/x-1992-2002/remont/memory-modules/#memory-system__diagnostic-system-check) .
2. Disconnect MSM Light Green 6-pin connector C2. Using DVOM, check voltage between MSM harness connector C2 terminals "D" (Orange wire) and "C" (Black wire). If reading is about 12 volts, go to next step. If reading is not about 12 volts, go to step 5).
3. Disconnect left seat switch connector. Check voltage between MSM harness connector C2 terminal "D" (Orange wire) and left seat switch harness connector terminal "H" (Black wire). If reading is about 12 volts, go to next step. If reading is not about 12 volts, go to step 6).
4. Replace left seat switch. See appropriate POWER SEATS article. Perform «DIAGNOSTIC SYSTEM CHECK»(/cadillac/eldorado/x-1992-2002/remont/memory-modules/#memory-system__diagnostic-system-check) .
5. Repair open in circuit No. 850 (Black wire) between MSM and ground. Perform «DIAGNOSTIC SYSTEM CHECK»(/cadillac/eldorado/x-1992-2002/remont/memory-modules/#memory-system__diagnostic-system-check) .
6. Repair open in circuit No. 850 (Black wire) between left seat switch and ground. Perform «DIAGNOSTIC SYSTEM CHECK»(/cadillac/eldorado/x-1992-2002/remont/memory-modules/#memory-system__diagnostic-system-check) .

LEFT SEAT DOES NOT MANUALLY MOVE IN ONE DIRECTION

1. If diagnostic system check was performed, go to next step. If diagnostic system check was not performed, go to «DIAGNOSTIC SYSTEM CHECK»(/cadillac/eldorado/x-1992-2002/remont/memory-modules/#memory-system__diagnostic-system-check) .
2. Turn ignition off. Enter Mode 1 Diagnostics by grounding MSM diagnostic connector, located under left seat (connector must remain grounded throughout test). MSM should beep once to confirm that Mode 1 Diagnostics has been entered. While in Mode 1 Diagnostics, all seat and recliner movements are disabled. If one beep was heard, go to next step. If one beep was not heard, go to step 7).
3. Move left seat switch to inoperative position. If MSM beeps once when switch is moved to inoperative position, go to step 8). If MSM does not beep once when switch is moved to inoperative position, go to next step.
4. Disconnect left seat switch connector. Move left seat switch to inoperative position. Using DVOM, check resistance between ground and appropriate left seat switch terminal (switch-side). See «WIRING DIAGRAMS»(/cadillac/eldorado/x-1992-2002/remont/memory-modules/#memory-system) . If resistance is less than 5 ohms, go to next step. If resistance is not less than 5 ohms, go to step 6).
5. Repair open in appropriate wire. See «WIRING DIAGRAMS»(/cadillac/eldorado/x-1992-2002/remont/memory-modules/#memory-system) . Perform «DIAGNOSTIC SYSTEM CHECK»(/cadillac/eldorado/x-1992-2002/remont/memory-modules/#memory-system__diagnostic-system-check) .
6. Replace left seat switch. See appropriate POWER SEATS article. Perform «DIAGNOSTIC SYSTEM CHECK»(/cadillac/eldorado/x-1992-2002/remont/memory-modules/#memory-system__diagnostic-system-check) .
7. Check power and ground circuits to MSM. See «WIRING DIAGRAMS»(/cadillac/eldorado/x-1992-2002/remont/memory-modules/#memory-system) . Check for poor connections at MSM. If circuits and connections are okay, replace MSM. Perform «DIAGNOSTIC SYSTEM CHECK»(/cadillac/eldorado/x-1992-2002/remont/memory-modules/#memory-system__diagnostic-system-check) .
8. Disconnect suspect seat motor. Connect a fused jumper wire between one motor terminal and battery voltage. Connect another fused jumper wire between other motor terminal and ground. If motor runs, go to next step. If motor does not run, go to step 10).
9. Repair open or short to ground in appropriate wire between suspect motor and MSM. See «WIRING DIAGRAMS»(/cadillac/eldorado/x-1992-2002/remont/memory-modules/#memory-system) . Perform DIAGNOSTIC SYSTEM CHECK.
10. Replace suspect seat motor. See «SEATS - POWER»(/cadillac/eldorado/x-1992-2002/remont/seats/#power-seat-system) article. Perform «DIAGNOSTIC SYSTEM CHECK»(/cadillac/eldorado/x-1992-2002/remont/memory-modules/#memory-system__diagnostic-system-check) .

LEFT LUMBAR SUPPORT DOES NOT MANUALLY MOVE IN ANY DIRECTION

1. If diagnostic system check was performed, go to next step. If diagnostic system check was not performed, go to «DIAGNOSTIC SYSTEM CHECK»(/cadillac/eldorado/x-1992-2002/remont/memory-modules/#memory-system__diagnostic-system-check) .
2. Disconnect MSM Light Green 6-pin connector C2. Using DVOM, check voltage between MSM harness connector C2 terminals "D" (Orange wire) and "C" (Black wire). If reading is about 12 volts, go to next step. If reading is not about 12 volts, go to step 5).
3. Disconnect left lumbar switch connector. Check voltage between MSM harness connector C2 terminal "D" (Orange wire) and left lumbar switch harness connector terminal "E" (Black wire). If reading is about 12 volts, go to next step. If reading is not about 12 volts, go to step 6).
4. Replace left lumbar switch. See appropriate POWER SEATS article. Perform «DIAGNOSTIC SYSTEM CHECK»(/cadillac/eldorado/x-1992-2002/remont/memory-modules/#memory-system__diagnostic-system-check) .
5. Repair open in circuit No. 850 (Black wire) between MSM and ground. Perform «DIAGNOSTIC SYSTEM CHECK»(/cadillac/eldorado/x-1992-2002/remont/memory-modules/#memory-system__diagnostic-system-check) .
6. Repair open in circuit No. 850 (Black wire) between left lumbar switch and ground. Perform «DIAGNOSTIC SYSTEM CHECK»(/cadillac/eldorado/x-1992-2002/remont/memory-modules/#memory-system__diagnostic-system-check) .

LEFT LUMBAR SUPPORT DOES NOT MANUALLY MOVE IN ONE DIRECTION

1. If diagnostic system check was performed, go to next step. If diagnostic system check was not performed, go to «DIAGNOSTIC SYSTEM CHECK»(/cadillac/eldorado/x-1992-2002/remont/memory-modules/#memory-system__diagnostic-system-check) .
2. Turn ignition off. Enter Mode 1 Diagnostics by grounding MSM diagnostic connector, located under left seat (connector must remain grounded throughout test). MSM should beep once to confirm that Mode 1 Diagnostics has been entered. While in Mode 1 Diagnostics, all seat and recliner movements are disabled. If one beep was heard, go to next step. If one beep was not heard, go to step 7).
3. Move left lumbar switch to inoperative position. If MSM beeps once when switch is moved to inoperative position, go to step 8). If MSM does not beep once when switch is moved to inoperative position, go to next step.
4. Disconnect left lumbar switch connector. Move left lumbar switch to inoperative position. Using DVOM, check resistance between ground and appropriate left lumbar switch terminal (switch-side). See «WIRING DIAGRAMS»(/cadillac/eldorado/x-1992-2002/remont/memory-modules/#memory-system) . If resistance is less than 5 ohms, go to next step. If resistance is not less than 5 ohms, go to step 6).
5. Repair open in appropriate wire. See «WIRING DIAGRAMS»(/cadillac/eldorado/x-1992-2002/remont/memory-modules/#memory-system) . Perform «DIAGNOSTIC SYSTEM CHECK»(/cadillac/eldorado/x-1992-2002/remont/memory-modules/#memory-system__diagnostic-system-check) .
6. Replace left lumbar switch. See appropriate POWER SEATS article. Perform «DIAGNOSTIC SYSTEM CHECK»(/cadillac/eldorado/x-1992-2002/remont/memory-modules/#memory-system__diagnostic-system-check) .
7. Check power and ground circuits to MSM. See «WIRING DIAGRAMS»(/cadillac/eldorado/x-1992-2002/remont/memory-modules/#memory-system) . Check for poor connections at MSM. If circuits and connections are okay, replace MSM. Perform «DIAGNOSTIC SYSTEM CHECK»(/cadillac/eldorado/x-1992-2002/remont/memory-modules/#memory-system__diagnostic-system-check) .
8. Disconnect suspect seat motor. Connect a fused jumper wire between one motor terminal and battery voltage. Connect another fused jumper wire between other motor terminal and ground. If motor runs, go to next step. If motor does not run, go to step 10).
9. Repair open or short to ground in appropriate wire between suspect motor and MSM. See «WIRING DIAGRAMS»(/cadillac/eldorado/x-1992-2002/remont/memory-modules/#memory-system) . Perform DIAGNOSTIC SYSTEM CHECK.
10. Replace suspect seat motor. See appropriate POWER SEATS article. Perform «DIAGNOSTIC SYSTEM CHECK»(/cadillac/eldorado/x-1992-2002/remont/memory-modules/#memory-system__diagnostic-system-check) .

1. If diagnostic system check was performed, go to next step. If diagnostic system check was not performed, go to «DIAGNOSTIC SYSTEM CHECK»(/cadillac/eldorado/x-1992-2002/remont/memory-modules/#memory-system__diagnostic-system-check) .
2. Using test light, backprobe between outside mirror switch connector terminal "E" (Orange wire) and ground. If test light illuminates, go to next step. If test light does not illuminate, go to step 7).
3. Using test light, backprobe between outside mirror switch connector terminals "E" (Orange wire) and "D" (Black wire). If test light illuminates, go to next step. If test light does not illuminate, go to step 8).
4. If both mirrors operate in all directions during memory recall functions, go to next step. If both mirrors do not operate in all directions during memory recall functions, go to step 6).
5. Replace outside mirror switch. See «MIRRORS - POWER»(/cadillac/eldorado/x-1992-2002/remont/mirrors/#power-mirror-system) article. Perform «DIAGNOSTIC SYSTEM CHECK»(/cadillac/eldorado/x-1992-2002/remont/memory-modules/#memory-system__diagnostic-system-check) .
6. Replace MMM. Perform «DIAGNOSTIC SYSTEM CHECK»(/cadillac/eldorado/x-1992-2002/remont/memory-modules/#memory-system__diagnostic-system-check) .
7. Repair open in circuit No. 1740 (Orange wire) between outside mirror switch and engine compartment fuse/relay center. Perform «DIAGNOSTIC SYSTEM CHECK»(/cadillac/eldorado/x-1992-2002/remont/memory-modules/#memory-system__diagnostic-system-check) .
8. Repair open in circuit No. 50 (Black wire) between outside mirror switch and ground. Perform «DIAGNOSTIC SYSTEM CHECK»(/cadillac/eldorado/x-1992-2002/remont/memory-modules/#memory-system__diagnostic-system-check) .

1. If diagnostic system check was performed, go to next step. If diagnostic system check was not performed, go to «DIAGNOSTIC SYSTEM CHECK»(/cadillac/eldorado/x-1992-2002/remont/memory-modules/#memory-system__diagnostic-system-check) .
2. Using test light, backprobe between outside mirror switch connector terminal "H" (Orange wire) and ground. If test light illuminates, go to next step. If test light does not illuminate, go to step 9).
3. Using test light, backprobe between outside mirror switch connector terminals "H" (Orange wire) and "A" (Black wire). If test light illuminates, go to next step. If test light does not illuminate, go to step 10).
4. Using test light, backprobe between outside mirror switch connector terminals "H" (Orange wire) and "C" (Tan/White wire). If test light illuminates, go to next step. If test light does not illuminate, go tostep 11).
5. Using test light, backprobe between outside mirror switch connector terminals "H" (Orange wire) and "B" (Brown wire). If test light illuminates, go to next step. If test light does not illuminate, go to step 11).
6. Using test light, backprobe between outside mirror switch connector terminals "H" (Orange wire) and MMM connector terminal F8 (Tan/White wire). If test light illuminates, go to next step. If test light does not illuminate, go to step 12).
7. Using test light, backprobe between outside mirror switch connector terminals "H" (Orange wire) and MMM connector terminal E8 (Brown wire). If test light illuminates, go to next step. If test light does not illuminate, go to step 13).
8. Replace MMM. Perform «DIAGNOSTIC SYSTEM CHECK»(/cadillac/eldorado/x-1992-2002/remont/memory-modules/#memory-system__diagnostic-system-check) .
9. Repair open in circuit No. 1740 (Orange wire) between outside mirror switch and engine compartment fuse/relay center. Perform «DIAGNOSTIC SYSTEM CHECK»(/cadillac/eldorado/x-1992-2002/remont/memory-modules/#memory-system__diagnostic-system-check) .
10. Repair open in circuit No. 50 (Black wire) between outside mirror switch and ground. Perform «DIAGNOSTIC SYSTEM CHECK»(/cadillac/eldorado/x-1992-2002/remont/memory-modules/#memory-system__diagnostic-system-check) .
11. Replace outside mirror switch. See appropriate POWER MIRRORS article. Perform «DIAGNOSTIC SYSTEM CHECK»(/cadillac/eldorado/x-1992-2002/remont/memory-modules/#memory-system__diagnostic-system-check) .
12. Repair open in circuit No. 942 (Tan/White wire) between outside mirror switch and MMM. Perform «DIAGNOSTIC SYSTEM CHECK»(/cadillac/eldorado/x-1992-2002/remont/memory-modules/#memory-system__diagnostic-system-check) .
13. Repair open in circuit No. 945 (Brown wire) between outside mirror switch and MMM. Perform «DIAGNOSTIC SYSTEM CHECK»(/cadillac/eldorado/x-1992-2002/remont/memory-modules/#memory-system__diagnostic-system-check) .

1. If diagnostic system check was performed, go to next step. If diagnostic system check was not performed, go to «DIAGNOSTIC SYSTEM CHECK»(/cadillac/eldorado/x-1992-2002/remont/memory-modules/#memory-system__diagnostic-system-check) .
2. Using test light, backprobe between outside mirror switch connector terminals "E" (Orange wire) and "B" (White wire). Operate mirror switch up. Backprobe between outside mirror switch connector terminals "D" (Black wire) and "B" (White wire). Operate mirror switch down. If test light illuminates, go to next step. If test light does not illuminate, go to step 9).
3. Using test light, backprobe between outside mirror switch connector terminals "E" (Orange wire) and "F" (Yellow wire). Operate mirror switch up. Backprobe between outside mirror switch connector terminals "D" (Black wire) and "F" (Yellow wire). Operate mirror switch down. If test light illuminates, go to next step. If test light does not illuminate, go to step 9).
4. If both mirrors operate up and down during memory recall functions, go to next step. If both mirrors do not operate up and down during memory recall functions, go to step 8).
5. Disconnect outside mirror switch connector. Disconnect MMM 32-pin connector C1. Using DVOM, check resistance between MMM harness connector C1 terminal F8 (White wire) and outside mirror switch harness connector terminal "B" (White wire). If resistance is 5 ohms or less, go to next step. If resistance is not 5 ohms or less, go to step 7).
6. Repair open in circuit No. 1517 (Yellow wire) between outside mirror switch and MMM connector C1. Perform «DIAGNOSTIC SYSTEM CHECK»(/cadillac/eldorado/x-1992-2002/remont/memory-modules/#memory-system__diagnostic-system-check) .
7. Repair open in circuit No. 889 (White wire) between outside mirror switch and MMM connector C1. Perform «DIAGNOSTIC SYSTEM CHECK»(/cadillac/eldorado/x-1992-2002/remont/memory-modules/#memory-system__diagnostic-system-check) .
8. Replace MMM. Perform «DIAGNOSTIC SYSTEM CHECK»(/cadillac/eldorado/x-1992-2002/remont/memory-modules/#memory-system__diagnostic-system-check) .
9. Replace outside mirror switch. See «MIRRORS - POWER»(/cadillac/eldorado/x-1992-2002/remont/mirrors/#power-mirror-system) article. Perform «DIAGNOSTIC SYSTEM CHECK»(/cadillac/eldorado/x-1992-2002/remont/memory-modules/#memory-system__diagnostic-system-check) .

1. If diagnostic system check was performed, go to next step. If diagnostic system check was not performed, go to «DIAGNOSTIC SYSTEM CHECK»(/cadillac/eldorado/x-1992-2002/remont/memory-modules/#memory-system__diagnostic-system-check) .
2. Using test light, backprobe between outside mirror switch connector terminals "E" (Orange wire) and "A" (Red/White wire). Move mirror switch left. Backprobe between outside mirror switch connector terminals "D" (Black wire) and "A" (Red/White wire). Move mirror switch right. If test light illuminates at both positions, go to next step. If test light does not illuminate at both positions, go to step 9).
3. Using test light, backprobe between outside mirror switch connector terminals "E" (Orange wire) and "G" (White wire). Move mirror switch left. Backprobe between outside mirror switch connector terminals "D" (Black wire) and "G" (White wire). Move mirror switch right. If test light illuminates at both positions, go to next step. If test light does not illuminate at both positions, go to step 9).
4. If both mirrors operate left and right during memory recall function, go to next step. If both mirrors do not operate during memory recall function, go to step 8).
5. Disconnect outside mirror switch connector. Disconnect MMM 32-pin connector C1. Using DVOM, check resistance between MMM harness connector C1 terminal E8 (Red/White wire) and outside mirror switch harness connector terminal "A" (Red/White wire). If resistance is less than 5 ohms, go to next step. If resistance is not less than 5 ohms, go to step 7).
6. Repair open in circuit No. 1512 (White wire) between outside mirror switch and MMM connector C1. Perform «DIAGNOSTIC SYSTEM CHECK»(/cadillac/eldorado/x-1992-2002/remont/memory-modules/#memory-system__diagnostic-system-check) .
7. Repair open in circuit No. 881 (Red/White wire) between outside mirror switch and MMM connector C1. Perform «DIAGNOSTIC SYSTEM CHECK»(/cadillac/eldorado/x-1992-2002/remont/memory-modules/#memory-system__diagnostic-system-check) .
8. Replace MMM. Perform «DIAGNOSTIC SYSTEM CHECK»(/cadillac/eldorado/x-1992-2002/remont/memory-modules/#memory-system__diagnostic-system-check) .
9. Replace outside mirror switch. See appropriate POWER MIRRORS article. Perform «DIAGNOSTIC SYSTEM CHECK»(/cadillac/eldorado/x-1992-2002/remont/memory-modules/#memory-system__diagnostic-system-check) .

1. If diagnostic system check was performed, go to next step. If diagnostic system check was not performed, go to «DIAGNOSTIC SYSTEM CHECK»(/cadillac/eldorado/x-1992-2002/remont/memory-modules/#memory-system__diagnostic-system-check) .
2. Using mirror select switch, select left mirror. Using test light, backprobe between outside mirror switch connector terminals "E" (Orange wire) and "H" (Tan/White wire). Move mirror switch down. Move mirror switch left. Backprobe between outside mirror switch connector terminals "D" (Black wire) and "H" (Tan/White wire). Move mirror switch up. Move mirror switch right. If test light illuminates at all positions, go to next step. If test light does not illuminate at all positions, go to step 6).
3. If left mirror operates in all directions during memory recall function, go to next step. If left mirror does not operate in all directions during memory recall function, go to step 5).
4. Repair open in circuit No. 942 (Tan/White wire) between outside mirror switch and MMM connector C1. Perform «DIAGNOSTIC SYSTEM CHECK»(/cadillac/eldorado/x-1992-2002/remont/memory-modules/#memory-system__diagnostic-system-check) .
5. Replace MMM. Perform «DIAGNOSTIC SYSTEM CHECK»(/cadillac/eldorado/x-1992-2002/remont/memory-modules/#memory-system__diagnostic-system-check) .
6. Replace outside mirror switch. See «MIRRORS - POWER»(/cadillac/eldorado/x-1992-2002/remont/mirrors/#power-mirror-system) article. Perform «DIAGNOSTIC SYSTEM CHECK»(/cadillac/eldorado/x-1992-2002/remont/memory-modules/#memory-system__diagnostic-system-check) .

1. If diagnostic system check was performed, go to next step. If diagnostic system check was not performed, go to «DIAGNOSTIC SYSTEM CHECK»(/cadillac/eldorado/x-1992-2002/remont/memory-modules/#memory-system__diagnostic-system-check) .
2. Using mirror select switch, select left mirror. Using test light, backprobe between outside mirror switch connector terminals "H" (Orange wire) and "E" (Yellow wire). If test light illuminates, go to next step. If test light does not illuminate, go to step 7).
3. Using test light, backprobe between outside mirror switch connector terminals "H" (Orange wire) and "D" (White wire). If test light illuminates, go to next step. If test light does not illuminate, go to step 7).
4. Using test light, backprobe between outside mirror switch connector terminal "H" (Orange wire) and MMM connector terminal F7 (Yellow wire). If test light illuminates, go to next step. If test light does not illuminate, go to step 8).
5. Using test light, backprobe between outside mirror switch connector terminal "H" (Orange wire) and MMM connector terminal E7 (White wire). If test light illuminates, go to next step. If test light does not illuminate, go to step 9).
6. Replace MMM. Perform «DIAGNOSTIC SYSTEM CHECK»(/cadillac/eldorado/x-1992-2002/remont/memory-modules/#memory-system__diagnostic-system-check) .
7. Replace outside mirror switch. See «MIRRORS - POWER»(/cadillac/eldorado/x-1992-2002/remont/mirrors/#power-mirror-system) article. Perform «DIAGNOSTIC SYSTEM CHECK»(/cadillac/eldorado/x-1992-2002/remont/memory-modules/#memory-system__diagnostic-system-check) .
8. Repair open in circuit No. 1517 (Yellow wire) between outside mirror switch and MMM. Perform «DIAGNOSTIC SYSTEM CHECK»(/cadillac/eldorado/x-1992-2002/remont/memory-modules/#memory-system__diagnostic-system-check) .
9. Repair open in circuit No. 1512 (White wire) between outside mirror switch and MMM. Perform «DIAGNOSTIC SYSTEM CHECK»(/cadillac/eldorado/x-1992-2002/remont/memory-modules/#memory-system__diagnostic-system-check) .

1. If diagnostic system check was performed, go to next step. If diagnostic system check was not performed, go to «DIAGNOSTIC SYSTEM CHECK»(/cadillac/eldorado/x-1992-2002/remont/memory-modules/#memory-system__diagnostic-system-check) .
2. Using mirror select switch, select right mirror. Using test light, backprobe between outside mirror switch connector terminals "E" (Orange wire) and "C" (Brown wire). Move mirror switch down. Move mirror switch left. Backprobe between outside mirror switch connector terminals "D" (Black wire) and "C" (Brown wire). Move mirror switch up. Move mirror switch right. If test light illuminates at all positions, go to next step. If test light does not illuminate at all positions, go to step 6).
3. If right mirror operates in all directions during memory recall function, go to next step. If right mirror does not operate in all directions during memory recall function, go to step 5).
4. Repair open in circuit No. 945 (Brown wire) between outside mirror switch and MMM connector C1. Perform «DIAGNOSTIC SYSTEM CHECK»(/cadillac/eldorado/x-1992-2002/remont/memory-modules/#memory-system__diagnostic-system-check) .
5. Replace MMM. Perform «DIAGNOSTIC SYSTEM CHECK»(/cadillac/eldorado/x-1992-2002/remont/memory-modules/#memory-system__diagnostic-system-check) .
6. Replace outside mirror switch. See «MIRRORS - POWER»(/cadillac/eldorado/x-1992-2002/remont/mirrors/#power-mirror-system) article. Perform «DIAGNOSTIC SYSTEM CHECK»(/cadillac/eldorado/x-1992-2002/remont/memory-modules/#memory-system__diagnostic-system-check) .

1. If diagnostic system check was performed, go to next step. If diagnostic system check was not performed, go to «DIAGNOSTIC SYSTEM CHECK»(/cadillac/eldorado/x-1992-2002/remont/memory-modules/#memory-system__diagnostic-system-check) .
2. Using mirror select switch, select right mirror. Using test light, backprobe between outside mirror switch connector terminals "H" (Orange wire) and "F" (Purple/White wire). If test light illuminates, go to next step. If test light does not illuminate, go to step 7).
3. Using test light, backprobe between outside mirror switch connector terminals "H" (Orange wire) and "G" (Red/White wire). If test light illuminates, go to next step. If test light does not illuminate, go tostep 7).
4. Using test light, backprobe between outside mirror switch connector terminal "H" (Orange wire) and MMM connector terminal E6 (Purple/White wire). If test light illuminates, go to next step. If test light does not illuminate, go to step 8).
5. Using test light, backprobe between outside mirror switch connector terminal "H" (Orange wire) and MMM connector terminal F6 (Red/White wire). If test light illuminates, go to next step. If test light does not illuminate, go to step 9).
6. Replace MMM. Perform «DIAGNOSTIC SYSTEM CHECK»(/cadillac/eldorado/x-1992-2002/remont/memory-modules/#memory-system__diagnostic-system-check) .
7. Replace outside mirror switch. See «MIRRORS - POWER»(/cadillac/eldorado/x-1992-2002/remont/mirrors/#power-mirror-system) article. Perform «DIAGNOSTIC SYSTEM CHECK»(/cadillac/eldorado/x-1992-2002/remont/memory-modules/#memory-system__diagnostic-system-check) .
8. Repair open in circuit No. 889 (Purple/White wire) between outside mirror switch and MMM. Perform «DIAGNOSTIC SYSTEM CHECK»(/cadillac/eldorado/x-1992-2002/remont/memory-modules/#memory-system__diagnostic-system-check) .
9. Repair open in circuit No. 881 (Red/White wire) between outside mirror switch and MMM. Perform «DIAGNOSTIC SYSTEM CHECK»(/cadillac/eldorado/x-1992-2002/remont/memory-modules/#memory-system__diagnostic-system-check) .

Left Mirror

1. If diagnostic system check was performed, go to next step. If diagnostic system check was not performed, go to «DIAGNOSTIC SYSTEM CHECK»(/cadillac/eldorado/x-1992-2002/remont/memory-modules/#memory-system__diagnostic-system-check) .
2. Disconnect left outside mirror connector C1. Connect a fused jumper wire between component-side of outside mirror connector C1 terminal "A" (Light Blue wire) and battery voltage. Connect another fused jumper wire between component-side of outside mirror connector C1 terminal "B" (White wire) and ground. If left/right motor runs, go to next step. If left/right motor does not run, go to step 6).
3. Disconnect MMM connector. Using DVOM, check resistance between MMM harness connector terminal E11 (White wire) and outside mirror harness connector C1 terminal "B" (White wire). If resistance is 5 ohms or less, go to next step. If resistance is not 5 ohms or less, go to step 7).
4. Check resistance between MMM harness connector terminal E13 (Light Blue wire) and outside mirror harness connector C1 terminal "A" (Light Blue wire). If resistance is 5 ohms or less, go to next step. If resistance is not 5 ohms or less, go to step 8).
5. Replace MMM. Perform «DIAGNOSTIC SYSTEM CHECK»(/cadillac/eldorado/x-1992-2002/remont/memory-modules/#memory-system__diagnostic-system-check) .
6. Replace left outside mirror. See «MIRRORS - POWER»(/cadillac/eldorado/x-1992-2002/remont/mirrors/#power-mirror-system) article. Perform «DIAGNOSTIC SYSTEM CHECK»(/cadillac/eldorado/x-1992-2002/remont/memory-modules/#memory-system__diagnostic-system-check) .
7. Repair open in circuit No. 81 (White wire) between left outside mirror and MMM. Perform «DIAGNOSTIC SYSTEM CHECK»(/cadillac/eldorado/x-1992-2002/remont/memory-modules/#memory-system__diagnostic-system-check) .
8. Repair open in circuit No. 82 (Light Blue wire) between left outside mirror and MMM. Perform «DIAGNOSTIC SYSTEM CHECK»(/cadillac/eldorado/x-1992-2002/remont/memory-modules/#memory-system__diagnostic-system-check) .

Right Mirror

1. If diagnostic system check was performed, go to next step. If diagnostic system check was not performed, go to «DIAGNOSTIC SYSTEM CHECK»(/cadillac/eldorado/x-1992-2002/remont/memory-modules/#memory-system__diagnostic-system-check) .
2. Disconnect right outside mirror connector C1. Connect a fused jumper wire between component-side of outside mirror connector C1 terminal "A" (Gray wire) and battery voltage. Connect another fused jumper wire between component-side of outside mirror connector C1 terminal "B" (Red/White wire) and ground. If left/right motor runs, go to next step. If left/right motor does not run, go to step 6).
3. Disconnect MMM connector. Using DVOM, check resistance between MMM harness connector terminal F11 (Red/White wire) and outside mirror harness connector C1 terminal "B" (Red/White wire). If resistance is 5 ohms or less, go to next step. If resistance is not 5 ohms or less, go to step 7).
4. Check resistance between MMM harness connector terminal F13 (Gray wire) and outside mirror harness connector C1 terminal "A" (Gray wire). If resistance is 5 ohms or less, go to next step. If resistance is not 5 ohms or less, go to step 8).
5. Replace MMM. Perform «DIAGNOSTIC SYSTEM CHECK»(/cadillac/eldorado/x-1992-2002/remont/memory-modules/#memory-system__diagnostic-system-check) .
6. Replace right outside mirror. See «MIRRORS - POWER»(/cadillac/eldorado/x-1992-2002/remont/mirrors/#power-mirror-system) article. Perform «DIAGNOSTIC SYSTEM CHECK»(/cadillac/eldorado/x-1992-2002/remont/memory-modules/#memory-system__diagnostic-system-check) .
7. Repair open in circuit No. 881 (Red/White wire) between right outside mirror and MMM. Perform «DIAGNOSTIC SYSTEM CHECK»(/cadillac/eldorado/x-1992-2002/remont/memory-modules/#memory-system__diagnostic-system-check) .
8. Repair open in circuit No. 90 (Gray wire) between right outside mirror and MMM. Perform «DIAGNOSTIC SYSTEM CHECK»(/cadillac/eldorado/x-1992-2002/remont/memory-modules/#memory-system__diagnostic-system-check) .

1. If diagnostic system check was performed, go to next step. If diagnostic system check was not performed, go to «DIAGNOSTIC SYSTEM CHECK»(/cadillac/eldorado/x-1992-2002/remont/memory-modules/#memory-system__diagnostic-system-check) .
2. Disconnect left outside mirror connector C1. Connect a fused jumper wire between component-side of outside mirror connector C1 terminal "C" (Light Green wire) and battery voltage. Connect another fused jumper wire between component-side of outside mirror connector C1 terminal "D" (Yellow wire) and ground. If up/down motor runs, go to next step. If up/down motor does not run, go to step 6).
3. Disconnect MMM connector. Using DVOM, check resistance between MMM harness connector terminal F10 (Yellow wire) and outside mirror harness connector C1 terminal "D" (Yellow wire). If resistance is 5 ohms or less, go to next step. If resistance is not 5 ohms or less, go to step 7).
4. Check resistance between MMM harness connector terminal F12 (Light Green wire) and outside mirror harness connector C1 terminal "C" (Light Green wire). If resistance is 5 ohms or less, go to next step. If resistance is not 5 ohms or less, go to step 8).
5. Replace MMM. Perform «DIAGNOSTIC SYSTEM CHECK»(/cadillac/eldorado/x-1992-2002/remont/memory-modules/#memory-system__diagnostic-system-check) .
6. Replace left outside mirror. See «MIRRORS - POWER»(/cadillac/eldorado/x-1992-2002/remont/mirrors/#power-mirror-system) article. Perform «DIAGNOSTIC SYSTEM CHECK»(/cadillac/eldorado/x-1992-2002/remont/memory-modules/#memory-system__diagnostic-system-check) .
7. Repair open in circuit No. 88 (Light Green wire) between left outside mirror and MMM. Perform «DIAGNOSTIC SYSTEM CHECK»(/cadillac/eldorado/x-1992-2002/remont/memory-modules/#memory-system__diagnostic-system-check) .
8. Repair open in circuit No. 89 (Yellow wire) between left outside mirror and MMM. Perform «DIAGNOSTIC SYSTEM CHECK»(/cadillac/eldorado/x-1992-2002/remont/memory-modules/#memory-system__diagnostic-system-check) .

1. If diagnostic system check was performed, go to next step. If diagnostic system check was not performed, go to «DIAGNOSTIC SYSTEM CHECK»(/cadillac/eldorado/x-1992-2002/remont/memory-modules/#memory-system__diagnostic-system-check) .
2. Disconnect right outside mirror connector C1. Connect a fused jumper wire between component-side of outside mirror connector C1 terminal "C" (Purple/White wire) and battery voltage. Connect another fused jumper wire between component-side of outside mirror connector C1 terminal "D" (Brown/White wire) and ground. If up/down motor runs, go to next step. If up/down motor does not run, go to step 6).
3. Disconnect MMM connector. Using DVOM, check resistance between MMM harness connector terminal E10 (Brown/White wire) and outside mirror harness connector C1 terminal "D" (Brown/White wire). If resistance is 5 ohms or less, go to next step. If resistance is not 5 ohms or less, go to step 7).
4. Check resistance between MMM harness connector terminal E12 (Purple/White wire) and outside mirror harness connector C1 terminal "C" (Purple/White wire). If resistance is 5 ohms or less, go to next step. If resistance is not 5 ohms or less, go to step 8).
5. Replace MMM. Perform «DIAGNOSTIC SYSTEM CHECK»(/cadillac/eldorado/x-1992-2002/remont/memory-modules/#memory-system__diagnostic-system-check) .
6. Replace right outside mirror. See «MIRRORS - POWER»(/cadillac/eldorado/x-1992-2002/remont/mirrors/#power-mirror-system) article. Perform «DIAGNOSTIC SYSTEM CHECK»(/cadillac/eldorado/x-1992-2002/remont/memory-modules/#memory-system__diagnostic-system-check) .
7. Repair open in circuit No. 1498 (Brown/White wire) between right outside mirror and MMM. Perform «DIAGNOSTIC SYSTEM CHECK»(/cadillac/eldorado/x-1992-2002/remont/memory-modules/#memory-system__diagnostic-system-check) .
8. Repair open in circuit No. 889 (Purple/White wire) between right outside mirror and MMM. Perform «DIAGNOSTIC SYSTEM CHECK»(/cadillac/eldorado/x-1992-2002/remont/memory-modules/#memory-system__diagnostic-system-check) .

MEMORY FUNCTION SWITCH INOPERATIVE

1. If diagnostic system check was performed, go to next step. If diagnostic system check was not performed, go to «DIAGNOSTIC SYSTEM CHECK»(/cadillac/eldorado/x-1992-2002/remont/memory-modules/#memory-system__diagnostic-system-check) .
2. Using test light, backprobe between MMM connector terminal E1 (Orange wire) and memory function switch connector terminal "E" (Black wire). If test light illuminates, go to next step. If test light does not illuminate, go to step 6).
3. Using test light, backprobe between MMM connector terminal E1 (Orange wire) and appropriate memory function connector switch terminal. See «WIRING DIAGRAMS»(/cadillac/eldorado/x-1992-2002/remont/memory-modules/#memory-system) . Operate suspect memory switch. If test light illuminates, go to next step. If test light does not illuminate, go to step 7).
4. Using test light, backprobe between MMM connector terminal E1 (Orange wire) and appropriate MMM connector terminal. See «WIRING DIAGRAMS»(/cadillac/eldorado/x-1992-2002/remont/memory-modules/#memory-system) . Operate suspect memory switch. If test light illuminates, go to next step. If test light does not illuminate, go to step 8).
5. Replace MMM. Perform «DIAGNOSTIC SYSTEM CHECK»(/cadillac/eldorado/x-1992-2002/remont/memory-modules/#memory-system__diagnostic-system-check) .
6. Check for open in Black wire between memory function switch and ground. If circuit is okay, go to next step. If circuit is not okay, go to step 9).
7. Replace memory function switch. Perform «DIAGNOSTIC SYSTEM CHECK»(/cadillac/eldorado/x-1992-2002/remont/memory-modules/#memory-system__diagnostic-system-check) .
8. Repair problem in appropriate wire. See «WIRING DIAGRAMS»(/cadillac/eldorado/x-1992-2002/remont/memory-modules/#memory-system) . Perform «DIAGNOSTIC SYSTEM CHECK»(/cadillac/eldorado/x-1992-2002/remont/memory-modules/#memory-system__diagnostic-system-check) .
9. Repair open in Black wire between memory function switch and ground. Perform «DIAGNOSTIC SYSTEM CHECK»(/cadillac/eldorado/x-1992-2002/remont/memory-modules/#memory-system__diagnostic-system-check) .

SELF-DIAGNOSTICS

Note. Diagnostic trouble code tests are written specifically for use with GM Tech I or Tech II scan tools. Generic scan tool can be used, but may have limited functions.

Check for Diagnostic Trouble Codes (DTCs). See RETRIEVING DIAGNOSTIC TROUBLE CODES (DTCS) . If no DTCs exist, proceed to TROUBLE SHOOTING and diagnose vehicle by symptom. If DTCs exist, go to MEMORY SEAT MODULE (MSM) DIAGNOSTIC TROUBLE CODES . Perform appropriate DTC test. After repair is complete, clear DTCs. See CLEARING DIAGNOSTIC TROUBLE CODES (DTCS) . Recheck system operation.

RETRIEVING DIAGNOSTIC TROUBLE CODES (DTCS)

Note. Use of Tech 1 or 2 scan tool is required to retrieve DTCs. Refer to user reference manuals supplied with scan tool.

CLEARING DIAGNOSTIC TROUBLE CODES (DTCS)

To clear DTCs from memory, either to determine if malfunction will occur again or after making necessary repairs, disconnect power supply to Powertrain Control Module (PCM) for at least 30 seconds or clear codes using a scan tool.

MANUAL DIAGNOSTIC FEATURE

1. When MSM diagnostic connector (taped to body harness) is grounded, one chime will sound to indicate MSM has entered Diagnostic Mode 1. MSM diagnostic connector must remain grounded for entire test. During Mode 1, all seat switch inputs are tested and all seat movement is disabled. When each switch is activated, one chime will sound. If a switch is activated and no chime is heard, MSM did not receive input.
2. To enter Mode 2, remove ground from MSM diagnostic connector, and re-establish ground within 5 seconds. During Mode 2, all position sensors are tested and seats will move. As seat is moved, MSM will test seat position sensor for a gradual voltage change. If a large change or no change in feedback voltage occurs, a chime will sound. 3) To exit either diagnostic mode, remove ground for more than 5 seconds. When diagnostic mode is exited, 3 chimes will sound.

DIAGNOSTIC TROUBLE CODES (DTCS)

MEMORY SEAT MODULE (MSM) DTCS (1)

MEMORY MIRROR MODULE (MMM) DTCS (1)

Memory Seat Module (MSM) performs self-tests on its EEPROM. MSM DTC B1656 and B1658 will set when MSM detects a problem with the EEPROM. When MSM DTC B1656 is set, module will store value being written on another block of EEPROM. When MSM DTC B1658 is set, module will use default values for blocks of EEPROM that are corrupt. DTCs will clear when self-test indicates that EEPROM is okay.

Diagnostic Procedures

Clear DTCs. See CLEARING DIAGNOSTIC TROUBLE CODES (DTCS) . Cycle ignition. Check for DTCs. See RETRIEVING DIAGNOSTIC TROUBLE CODES (DTCS) . If MSM DTC B1656 or B1658 is current, replace MSM.

Memory Seat Module (MSM) supplies a 5-volt reference voltage to all seat position sensors using circuit No. 788 (Gray wire). MSM DTC B0846 will set when 5-volt feed voltage is not about 4.6-5.2 volts. When DTC is set, MSM will not allow any memory recall function. Only manual seat movement is allowed, and only one motor can operate at a time. MSM DTC B0846 will clear when 5-volt feed voltage is within a valid operating range during the last monitoring cycle.

1. Turn ignition off. Disconnect front height position sensor connector. Using DVOM, check voltage between front height position sensor harness connector terminal "B" (Gray wire) and ground. If reading is about zero volts, go to step 5). If reading is not about zero volts, go to next step.
2. If reading is about 12 volts, go to step 6). If reading is not about 12 volts, go to next step.
3. Disconnect MSM 26-pin connector C1. Using DVOM, check resistance between MSM harness connector C1 terminal No. 13 (Gray wire) and ground. If resistance is about 5 ohms, go to next step. If resistance is not about 5 ohms, go to step 7).
4. Replace MSM. Go to step 7).
5. Repair short to ground in circuit No. 788 (Gray wire) between position sensor and MSM. Go to step 8).
6. Repair short to voltage in circuit No. 788 (Gray wire) between position sensor and MSM. Go to step 8).
7. Repair open in circuit No. 788 (Gray wire) between MSM 26-pin connector C1 and splice S348. Go to next step.
8. Clear DTCs. Reconnect all disconnected connectors. Recheck system operation.

Memory Seat Module (MSM) is supplied battery voltage from SEATS circuit breaker (30-amp) in left maxi-fuse block using circuit No. 742 (Red wire). This battery voltage is used to operate seat motors. MSM DTC B0856 will set when battery voltage falls out of range of 9-15.5 volts. MSM DTC B0856 will clear when dirty battery voltage is within a valid operating range during the last monitoring cycle.

Check battery for proper voltage, and repair or replace as necessary. If battery is okay, repair open or short in circuit No. 742 (Red wire) between MSM and left maxi-fuse block. Recheck system operation.

Memory Seat Module (MSM) is supplied battery voltage using circuit No. 1840 (Orange wire). MSM monitors battery voltage to ensure it is in within valid operating range. MSM DTC B1982 will set when battery voltage is greater than 15.5 volts. MSM DTC B1983 will set when battery voltage is less than 9 volts. When MSM DTC B1983 is set, MSM will try to "write" status of DTC to EEPROM, then no other "writes" to EEPROM will occur while DTC is current. MSM DTC B1982 or B1983 will clear when condition for setting the code no longer exists.

1. Turn ignition off. Connect scan tool to Data Link Connector (DLC). Select DATA from MSM DATA LIST. If reading is 9-15.5 volts, go to step 4). If reading is not 9-15.5 volts, go to next step.
2. Disconnect MSM Light Green 6-pin connector C2. Using DVOM, check voltage between MSM harness connector C2 terminal "D" (Orange wire) and ground. If reading is 9-15.5 volts, go to step 4). If reading is not 9-15.5 volts, go to next step.
3. Locate and repair problem in charging system. See appropriate «GENERATOR & REGULATOR»(/cadillac/eldorado/x-1992-2002/remont/charging-system/#charging-system) article in ELECTRICAL section. Recheck system operation.
4. Clear DTCs. See «CLEARING DIAGNOSTIC TROUBLE CODES (DTCS)»(/cadillac/eldorado/x-1992-2002/remont/memory-modules/#memory-system__clearing-diagnostic-trouble-codes-dtcs) under SELF-DIAGNOSTICS. Cycle ignition. Check for DTCs. See «RETRIEVING DIAGNOSTIC TROUBLE CODES (DTCS)»(/cadillac/eldorado/x-1992-2002/remont/memory-modules/#memory-system__retrieving-diagnostic-trouble-codes-dtcs) under SELF-DIAGNOSTICS. If DTC is current, replace MSM. Go to next step.
5. Clear DTCs. See «CLEARING DIAGNOSTIC TROUBLE CODES (DTCS)»(/cadillac/eldorado/x-1992-2002/remont/memory-modules/#memory-system__clearing-diagnostic-trouble-codes-dtcs) under SELF-DIAGNOSTICS. Reinstall and reconnect all components and connectors. Recheck system operation.

Diagnostic Aids

These DTCs will not allow most other DTCs to set. MSM DTC B1982 may set if vehicle is placed on a battery charger on fast charge for a long period of time.

Memory Seat Module (MSM) receives inputs from left seat switch (Eldorado and Seville only) and left lumbar switch. When switch is operated, it becomes grounded. The input is recognized by MSM, which moves seat or lumbar support in appropriate direction. If MSM continues to receive input from seat or lumbar support switch for 30 seconds after motion in requested direction has ceased, switch is considered shorted. If a seat or lumbar position sensor DTC is currently set and a switch in the associated direction of suspect sensor has been active for 30 seconds, switch is considered shorted.

Appropriate MSM DTC will set when a switch failure is detected. When DTC is set, associated motor outputs of suspect switch will be deactivated. MSM will continue to respond to valid inputs from other manual switches. All memory recall commands will be ignored. DTC will clear when MSM does not detect switch failure during last monitoring cycle.

1. Turn ignition off. Connect scan tool to Data Link Connector (DLC). Disconnect left seat switch (Eldorado and Seville only) or left lumbar switch. Using scan tool, clear DTCs. See «CLEARING DIAGNOSTIC TROUBLE CODES (DTCS)»(/cadillac/eldorado/x-1992-2002/remont/memory-modules/#memory-system__clearing-diagnostic-trouble-codes-dtcs) under SELF-DIAGNOSTICS. After 30 seconds, check for DTCs. See «RETRIEVING DIAGNOSTIC TROUBLE CODES (DTCS)»(/cadillac/eldorado/x-1992-2002/remont/memory-modules/#memory-system__retrieving-diagnostic-trouble-codes-dtcs) under SELF-DIAGNOSTICS. If DTC is reset, go to next step. If DTC is not reset, go tostep 3).
2. Repair short to ground in appropriate wire. See appropriate table under «DIAGNOSTIC TROUBLE CODES (DTCS)»(/cadillac/eldorado/x-1992-2002/remont/memory-modules/#memory-system__diagnostic-trouble-codes-dtcs) under SELF-DIAGNOSTICS. See «WIRING DIAGRAMS»(/cadillac/eldorado/x-1992-2002/remont/memory-modules/#memory-system) . Go to step 4).
3. Replace left seat switch (Eldorado and Seville) or left lumbar switch. See appropriate «SEATS - POWER»(/cadillac/eldorado/x-1992-2002/remont/seats/#power-seat-system) article. Recheck system operation.
4. Clear DTCs. See «CLEARING DIAGNOSTIC TROUBLE CODES (DTCS)»(/cadillac/eldorado/x-1992-2002/remont/memory-modules/#memory-system__clearing-diagnostic-trouble-codes-dtcs) under SELF-DIAGNOSTICS. Reinstall and reconnect all components and connectors. Recheck system operation.

Memory Seat Module (MSM) receives inputs from seat and lumbar position sensors during memory set, memory recall and easy exit functions. As motor moves seat and lumbar support, potentiometers in position sensors vary in resistance. MSM receives a variable voltage input depending on resistance of potentiometer. During memory set, MSM records voltage across all seat and lumbar potentiometers. During memory recall, MSM moves motors until voltage across each potentiometer matches stored voltages. During easy exit, MSM moves seat motors until voltages matched stored voltages. During normal operation, position sensors are checked against out-of-range limits.

DTCs will not set if MSM DTC B1982 or B1983 is current. Appropriate MSM DTC will set when a position sensor out-of-range is detected. MSM will set appropriate DTC when it detects the sensor input voltage is out of range (less than 0.25 volts or greater than 4.75 volts). When DTC is set, MSM will disable suspect motor during memory recall and easy exit functions. Motor will remain enabled for manual positioning. DTC will clear when MSM does not detect position sensor failure during last monitoring cycle.

1. Disconnect appropriate position connector. See appropriate table under «DIAGNOSTIC TROUBLE CODES (DTCS)»(/cadillac/eldorado/x-1992-2002/remont/memory-modules/#memory-system__diagnostic-trouble-codes-dtcs) under SELF-DIAGNOSTICS. On recline sensor, rear height sensor and forward/back sensor, use DVOM to check voltage between terminals "A" and "D". On front height sensor, lumbar in/out sensor and lumbar up/down sensor, use DVOM to check voltage between terminals "B" and "D". If reading is about 5 volts, go to next step. If reading is not about 5 volts, go to step 4).
2. Check for open or short in appropriate wire. See «WIRING DIAGRAMS»(/cadillac/eldorado/x-1992-2002/remont/memory-modules/#memory-system) . If circuit is okay, go to next step. If circuit is not okay, go to step 7).
3. Replace appropriate position sensor. Go to step 8).
4. Check for open or short in circuit No. 788 (Gray wire) between position sensor and splice S348. If circuit is okay, go to next step. If circuit is not okay, go to step 7).
5. Check for open or short in circuit No. 782 (Black wire) between position sensor and splice S349. If circuit is okay, go to next step. If circuit is not okay, go to step 7).
6. Check for poor connections at MSM 26-pin connector C1. If connections are okay, replace MSM. Go to step 8).
7. Repair open or short in appropriate wire. See «WIRING DIAGRAMS»(/cadillac/eldorado/x-1992-2002/remont/memory-modules/#memory-system) . Go to next step.
8. Clear DTCs. See «CLEARING DIAGNOSTIC TROUBLE CODES (DTCS)»(/cadillac/eldorado/x-1992-2002/remont/memory-modules/#memory-system__clearing-diagnostic-trouble-codes-dtcs) under SELF-DIAGNOSTICS. Reinstall and reconnect all components and connectors. Recheck system operation.

Memory Seat Module (MSM) supplies voltage to seat and lumbar motors when it receives input from manual switch or recall function. DTC will not set if MSM DTC B1982 or B1983 is current. MSM DTC B2130 will set when only one motor is being driven and motor's current draw is greater than 45 amps. When DTC is set, all seat movement is stopped. MSM DTC B2130 will clear when MSM does not detect seat motor failure during last monitoring cycle.

1. Disconnect left forward/back motor connector. Connect a fused jumper wire between one forward/back motor terminal and battery voltage. Connect another fused jumper wire between other forward/back motor terminal and ground. If forward/back motor runs, go to next step. If forward/back motor does not run, go to step 32).
2. Disconnect MSM Natural 6-pin connector C4. Using DVOM, check resistance between MSM harness connector C4 terminal "C" (Tan wire) and left forward/back motor harness connector terminal "A" (Tan wire). If resistance is less than 5 ohms, go to step 4). If resistance is not less than 5 ohms, go to next step.
3. Repair open in circuit No. 285 (Tan wire) between left forward/back motor and MSM connector C4. Recheck system operation.
4. Disconnect MSM Light Green 6-pin connector C2. Check resistance between MSM harness connector C2 terminal "A" (Light Green wire) and left forward/back motor harness connector terminal "B" (Light Green wire). If resistance is less than 5 ohms, go to step 6). If resistance is not less than 5 ohms, go to next step.
5. Repair open in circuit No. 284 (Light Green wire) between left forward/back motor and MSM connector C2. Recheck system operation.
6. Disconnect left rear height motor connector. Connect a fused jumper wire between one rear height motor terminal and battery voltage. Connect another fused jumper wire between other rear height motor terminal and ground. If rear height motor runs, go to next step. If rear height motor does not run, go to step 32).
7. Using DVOM, check resistance between MSM harness connector C4 terminal "E" (Yellow wire) and left rear height motor harness connector terminal "B" (Yellow wire). If resistance is less than 5 ohms, go to step 9). If resistance is not less than 5 ohms, go to next step.
8. Repair open in circuit No. 282 (Yellow wire) between left rear height motor and MSM connector C4. Recheck system operation.
9. Check resistance between MSM harness connector C2 terminal "B" (Light Blue wire) and left rear height motor harness connector terminal "A" (Light Blue wire). If resistance is less than 5 ohms, go to step 11). If resistance is not less than 5 ohms, go to next step.
10. Repair open in circuit No. 283 (Light Blue wire) between left rear height motor and MSM connector C2. Recheck system operation.
11. Disconnect left front height motor connector. Connect a fused jumper wire between one front height motor terminal and battery voltage. Connect another fused jumper wire between other front height motor terminal and ground. If front height motor runs, go to next step. If front height motor does not run, go to step 32).
12. Using DVOM, check resistance between MSM harness connector C4 terminal "A" (Dark Green wire) and left front height motor harness connector terminal "B" (Dark Green wire). If resistance is less than 5 ohms, go to step 14). If resistance is not less than 5 ohms, go to next step.
13. Repair open in circuit No. 286 (Dark Green wire) between left front height motor and MSM connector C4. Recheck system operation.
14. Disconnect MSM Black 6-pin connector C3. Using DVOM, check resistance between MSM harness connector C3 terminal "F" (Dark Blue wire) and left front height motor harness connector terminal "A" (Dark Blue wire). If resistance is less than 5 ohms, go to step 16). If resistance is not less than 5 ohms, go to next step.
15. Repair open in circuit No. 287 (Dark Blue wire) between left front height motor and MSM connector C3. Recheck system operation.
16. Disconnect left recline motor connector. Connect a fused jumper wire between one recline motor terminal and battery voltage. Connect another fused jumper wire between other recline motor terminal and ground. If recline motor runs, go to next step. If recline motor does not run, go to step 32).
17. Using DVOM, check resistance between MSM harness connector C4 terminal "D" (Light Green wire) and left recline motor harness connector terminal "B" (Light Green wire). If resistance is less than 5 ohms, go to step 19). If resistance is not less than 5 ohms, go to next step.
18. Repair open in circuit No. 276 (Light Green wire) between left recline motor and MSM connector C4. Recheck system operation.
19. Check resistance between MSM harness connector C2 terminal "F" (Light Blue wire) and left recline motor harness connector terminal "A" (Light Blue wire). If resistance is less than 5 ohms, go to step 21). If resistance is not less than 5 ohms, go to next step.
20. Repair open in circuit No. 277 (Light Blue wire) between left recline motor and MSM connector C2. Recheck system operation.
21. Disconnect left in/out lumbar motor connector. Connect a fused jumper wire between one in/out lumbar motor terminal and battery voltage. Connect another fused jumper wire between other in/out lumbar motor terminal and ground. If in/out lumbar motor runs, go to next step. If in/out lumbar motor does not run, go to step 32).
22. Using DVOM, check resistance between MSM harness connector C4 terminal "F" (Pink wire) and left in/out lumbar motor harness connector terminal "A" (Pink wire). If resistance is less than 5 ohms, go to step 24). If resistance is not less than 5 ohms, go to next step.
23. Repair open in circuit No. 610 (Pink wire) between left in/out lumbar motor and MSM connector C4. Recheck system operation.
24. Check resistance between MSM harness connector C3 terminal "B" (Dark Blue wire) and left in/out lumbar motor harness connector terminal "B" (Dark Blue wire). If resistance is less than 5 ohms, go to step 26). If resistance is not less than 5 ohms, go to next step.
25. Repair open in circuit No. 611 (Dark Blue wire) between left in/out lumbar motor and MSM connector C3. Recheck system operation.
26. Disconnect left up/down lumbar motor connector. Connect a fused jumper wire between one up/down lumbar motor terminal and battery voltage. Connect another fused jumper wire between other up/down lumbar motor terminal and ground. If up/down lumbar motor runs, go to next step. If up/down lumbar motor does not run, go to step 32).
27. Using DVOM, check resistance between MSM harness connector C3 terminal "A" (Tan wire) and left up/down lumbar motor harness connector terminal "A" (Tan wire). If resistance is less than 5 ohms, go to step 29). If resistance is not less than 5 ohms, go to next step.
28. Repair open in circuit No. 768 (Tan wire) between left up/down lumbar motor and MSM connector C3. Recheck system operation.
29. Check resistance between MSM harness connector C3 terminal "E" (Purple wire) and left up/down lumbar motor harness connector terminal "B" (Purple wire). If resistance is less than 5 ohms, go tostep 26). If resistance is not less than 5 ohms, go to next step.
30. Repair open in circuit No. 767 (Purple wire) between left up/down lumbar motor and MSM connector C3. Recheck system operation.
31. Clear DTCs. See «CLEARING DIAGNOSTIC TROUBLE CODES (DTCS)»(/cadillac/eldorado/x-1992-2002/remont/memory-modules/#memory-system__clearing-diagnostic-trouble-codes-dtcs) under SELF-DIAGNOSTICS. Cycle ignition. Operate all left seat motors. If MSM DTC B2130 resets, replace MSM. Recheck system operation.
32. Replace suspect seat motor. See appropriate «SEATS - POWER»(/cadillac/eldorado/x-1992-2002/remont/seats/#power-seat-system) article. Recheck system operation.

MSM DTC U1064: LOSS OF SERIAL COMMUNICATIONS (PZM)

Note. Platform Zone Module (PZM) may also be referred to as Body Control Module (BCM).

When ignition switch is in RUN position, all modules that communicate over the class 2 serial data bus send a State Of Health (SOH) message every 5 seconds to ensure system is operating properly. DTC will not set if MSM DTC B1982, B1983 or U1300 is current. MSM DTC U1064 will set when MSM does not receive an SOH message from PZM after 3 consecutive monitoring cycles. MSM DTC U1064 will clear when MSM detects an SOH message from PZM, conditions for setting DTC no longer exists or upon every power mode initialization.

Note. To identify circuit and components on class 2 serial data line, see appropriate wiring diagram in DATA LINK CONNECTORS article in WIRING DIAGRAMS.

1. MSM DTC U1064 does not necessarily represent an MSM failure. If DTCs are history, check each module on class 2 data line before diagnosing class 2 data line.
2. Clear all DTCs. See «CLEARING DIAGNOSTIC TROUBLE CODES (DTCS)»(/cadillac/eldorado/x-1992-2002/remont/memory-modules/#memory-system__clearing-diagnostic-trouble-codes-dtcs) under SELF-DIAGNOSTICS. Cycle ignition. Check for DTCs. See «RETRIEVING DIAGNOSTIC TROUBLE CODES (DTCS)»(/cadillac/eldorado/x-1992-2002/remont/memory-modules/#memory-system__retrieving-diagnostic-trouble-codes-dtcs) under SELF-DIAGNOSTICS. If no DTCs exist, recheck system operation.
3. If multiple DTCs exist, check for intermittent short to ground in circuit No. 1807 (Purple wire) between MSM and other modules on class 2 serial data line.
4. If DTC is current, use scan tool to establish communication with PZM. If communication cannot be established, see «BODY CONTROL MODULE»(/cadillac/eldorado/x-1992-2002/remont/body-cab-control-systems/#body-control-module) article. If communication can be established, replace MSM.
5. If DTC is history, check for intermittent open in circuit No. 1807 (Purple wire) between MSM and other modules on class 2 serial data line.

When ignition switch is in RUN position, all modules that communicate over the class 2 serial data bus send a State Of Health (SOH) message every 5 seconds to ensure system is operating properly.

DTC will not set if MSM DTC B1982, B1983 or U1300 is current. MSM DTC U1255 will set when MSM requests a message for initialization and the following criteria is met: Request is not acknowledged after all message retries are sent out, requested information contains an internal failsoft value, and the source ID with desired information is not known. MSM DTC U1255 will clear when conditions for setting DTC no longer exists or upon every power mode initialization.

Note. To identify circuit and components on class 2 serial data line, see appropriate wiring diagram in DATA LINK CONNECTORS article in WIRING DIAGRAMS.

1. MSM DTC U1255 does not necessarily represent an MSM failure. If DTCs are history, check each module on class 2 data line before diagnosing class 2 data line.
2. Clear all DTCs. See «CLEARING DIAGNOSTIC TROUBLE CODES (DTCS)»(/cadillac/eldorado/x-1992-2002/remont/memory-modules/#memory-system__clearing-diagnostic-trouble-codes-dtcs) under SELF-DIAGNOSTICS. Cycle ignition. Check for DTCs. See «RETRIEVING DIAGNOSTIC TROUBLE CODES (DTCS)»(/cadillac/eldorado/x-1992-2002/remont/memory-modules/#memory-system__retrieving-diagnostic-trouble-codes-dtcs) under SELF-DIAGNOSTICS. If MSM DTC U1255 is current, ensure all modules on class 2 serial data line are functioning properly. Check for short to ground or voltage in circuit No. 1807 (Purple wire) between MSM and other modules on class 2 serial data line. Check for poor connections at MSM. If components, circuit and connections are okay, replace MSM.

MSM DTC U1300: CLASS 2 SHORTED TO GROUND/VOLTAGE

Note. Platform Zone Module (PZM) may also be referred to as Body Control Module (BCM).

When ignition switch is in RUN position, all modules that communicate over the class 2 serial data bus send a State Of Health (SOH) message every 5 seconds to ensure system is operating properly. DTC will not set if MSM DTC B1982 or B1983 is current. MSM DTC U1300 will set when MSM detects that class 2 serial data line is shorted to ground or voltage for at least 3 seconds. MSM DTC U1300 will clear when conditions for setting DTC no longer exist.

Note. To identify circuit and components on class 2 serial data line, see appropriate wiring diagram in DATA LINK CONNECTORS article in WIRING DIAGRAMS.

MSM DTC U1300 cannot be received as current, as class 2 bus will not function during this condition. See BODY CONTROL MODULE article.

Memory Mirror Module (MMM) performs self-tests on its EEPROM. MMM DTC B1656 and B1658 will set if MMM detects a problem with the EEPROM. When MMM DTC B1656 is set, module will store value being written on another block of EEPROM. When MMM DTC B1658 is set, module will use default values for blocks of EEPROM that are corrupt. DTCs will clear when self-test indicates that EEPROM is okay.

Clear DTCs. See CLEARING DIAGNOSTIC TROUBLE CODES (DTCS) under SELF-DIAGNOSTICS. Cycle ignition. Check for DTCs. See RETRIEVING DIAGNOSTIC TROUBLE CODES (DTCS) under SELF-DIAGNOSTICS. If MMM DTC B1656 or B1658 is current, replace MMM.

Memory Mirror Module (MMM) is supplied battery voltage using circuit No. 1740 (Orange wire). MMM monitors battery voltage to ensure it is in within valid operating range. MMM DTC B1982 will set when battery voltage is greater than 15.5 volts. MMM DTC B1983 will set when battery voltage is less than 9 volts. When MMM DTC B1983 is set, MMM will try to "write" status of DTC to EEPROM, then no other "writes" to EEPROM will occur while DTC is current. MMM DTC B1982 or B1983 will clear when conditions for setting the code no longer exist.

1. Turn ignition off. Connect scan tool to Data Link Connector (DLC). Select DATA from MMM DATA LIST. If reading is 9-15.5 volts, go to step 4). If reading is not 9-15.5 volts, go to next step.
2. Disconnect MMM connector. Using DVOM, check voltage between MMM harness connector terminal E1 (Orange wire) and ground. If reading is 9-15.5 volts, go to step 4). If reading is not 9-15.5 volts, go to next step.
3. Locate and repair problem in charging system. See «GENERATOR & REGULATOR»(/cadillac/eldorado/x-1992-2002/remont/charging-system/#charging-system) article in ELECTRICAL section. Recheck system operation.
4. Clear DTCs. See «CLEARING DIAGNOSTIC TROUBLE CODES (DTCS)»(/cadillac/eldorado/x-1992-2002/remont/memory-modules/#memory-system__clearing-diagnostic-trouble-codes-dtcs) under SELF-DIAGNOSTICS. Cycle ignition. Check for DTCs. See «RETRIEVING DIAGNOSTIC TROUBLE CODES (DTCS)»(/cadillac/eldorado/x-1992-2002/remont/memory-modules/#memory-system__retrieving-diagnostic-trouble-codes-dtcs) under SELF-DIAGNOSTICS. If DTC is current, replace MMM. Go to next step.
5. Clear DTCs. See «CLEARING DIAGNOSTIC TROUBLE CODES (DTCS)»(/cadillac/eldorado/x-1992-2002/remont/memory-modules/#memory-system__clearing-diagnostic-trouble-codes-dtcs) under SELF-DIAGNOSTICS. Reinstall and reconnect all components and connectors. Recheck system operation.

These DTCs will not allow most other DTCs to set. MMM DTC B1982 may set if vehicle is placed on a battery charger on fast charge for a long period of time.

Description (Concours & DeVille)

Memory Mirror Module (MMM) receives inputs from left seat switch. When switch is operated, it becomes grounded. The input is recognized by MMM, which sends a class 2 message to MSM. MSM then moves seat in appropriate direction. If MMM continues to receive input from seat switch for 30 seconds after motion in requested direction has ceased, switch is considered shorted. If a seat position sensor DTC is currently set and a switch in the associated direction of suspect sensor has been active for 30 seconds, switch is considered shorted.

Appropriate MMM DTC will set when a switch failure is detected. When DTC is set, associated motor outputs of suspect switch will be deactivated. MMM will continue to respond to valid inputs from other manual switches. All memory recall commands will be ignored. DTC will clear when MMM does not detect switch failure during last monitoring cycle.

1. Turn ignition off. Connect scan tool to Data Link Connector (DLC). Disconnect left seat switch. Using scan tool, clear DTCs. See «CLEARING DIAGNOSTIC TROUBLE CODES (DTCS)»(/cadillac/eldorado/x-1992-2002/remont/memory-modules/#memory-system__clearing-diagnostic-trouble-codes-dtcs) under SELF-DIAGNOSTICS. After 30 seconds, check for DTCs. See «RETRIEVING DIAGNOSTIC TROUBLE CODES (DTCS)»(/cadillac/eldorado/x-1992-2002/remont/memory-modules/#memory-system__retrieving-diagnostic-trouble-codes-dtcs) under SELF-DIAGNOSTICS. If DTC is reset, go to next step. If DTC is not reset, go to step 3).
2. Repair short to ground in appropriate wire. See appropriate table under «DIAGNOSTIC TROUBLE CODES (DTCS)»(/cadillac/eldorado/x-1992-2002/remont/memory-modules/#memory-system__diagnostic-trouble-codes-dtcs) under SELF-DIAGNOSTICS. See «WIRING DIAGRAMS»(/cadillac/eldorado/x-1992-2002/remont/memory-modules/#memory-system) . Go to step 4).
3. Replace left seat switch. See «SEATS - POWER»(/cadillac/eldorado/x-1992-2002/remont/seats/#power-seat-system) article. Recheck system operation.
4. Clear DTCs. See «CLEARING DIAGNOSTIC TROUBLE CODES (DTCS)»(/cadillac/eldorado/x-1992-2002/remont/memory-modules/#memory-system__clearing-diagnostic-trouble-codes-dtcs) under SELF-DIAGNOSTICS. Reinstall and reconnect all components and connectors. Recheck system operation.

Memory Mirror Module (MMM) receives inputs from memory function switch. When a switch is operated, it becomes grounded. MMM recognizes each input, performs the requested action and sends a class 2 message to MSM. MSM then also performs the requested action. When any memory function switch input continues to be active for 30 seconds after motion in requested direction has ceased, switch is considered shorted.

Appropriate MMM DTC will set when a switch failure is detected. When DTC is set, associated motor outputs of suspect switch will be deactivated. MMM will continue to respond to valid inputs from other manual switches. All memory recall commands will be ignored. DTC will clear when MMM does not detect switch failure during last monitoring cycle.

1. Turn ignition off. Connect scan tool to Data Link Connector (DLC). Disconnect outside mirror switch or memory function switch. Using scan tool, clear DTCs. See «CLEARING DIAGNOSTIC TROUBLE CODES (DTCS)»(/cadillac/eldorado/x-1992-2002/remont/memory-modules/#memory-system__clearing-diagnostic-trouble-codes-dtcs) under SELF-DIAGNOSTICS. After 30 seconds, check for DTCs. See «RETRIEVING DIAGNOSTIC TROUBLE CODES (DTCS)»(/cadillac/eldorado/x-1992-2002/remont/memory-modules/#memory-system__retrieving-diagnostic-trouble-codes-dtcs) under SELF-DIAGNOSTICS. If DTC is reset, go to next step. If DTC is not reset, go to step 3).
2. Repair short to ground in appropriate wire. See appropriate table under «DIAGNOSTIC TROUBLE CODES (DTCS)»(/cadillac/eldorado/x-1992-2002/remont/memory-modules/#memory-system__diagnostic-trouble-codes-dtcs) under SELF-DIAGNOSTICS. See «WIRING DIAGRAMS»(/cadillac/eldorado/x-1992-2002/remont/memory-modules/#memory-system) . Go to step 4).
3. Replace memory function switch. Recheck system operation.
4. Clear DTCs. See «CLEARING DIAGNOSTIC TROUBLE CODES (DTCS)»(/cadillac/eldorado/x-1992-2002/remont/memory-modules/#memory-system__clearing-diagnostic-trouble-codes-dtcs) under SELF-DIAGNOSTICS. Reinstall and reconnect all components and connectors. Recheck system operation.

Memory Mirror Module (MMM) receives inputs from outside mirror switch. Mirror select switch must be placed in either right or left position in order to operate outside mirror switch. When mirror switch is operated, more than one input is sent from outside mirror switch to MMM. When MMM recognizes input combination, appropriate mirror will be moved in requested direction. If MMM does not recognize input combination as valid, input will be ignored and mirror will not be moved.

When any mirror switch input continues to be active for 30 seconds after motion in requested direction has ceased, switch is considered shorted. Appropriate MMM DTC will set when a switch failure is detected. When DTC is set, associated motor outputs of suspect switch will be deactivated. MMM will continue to respond to valid inputs from other manual switches. All memory recall commands will be ignored. DTC will clear when MMM does not detect switch failure during last monitoring cycle.

Clear DTCs. See CLEARING DIAGNOSTIC TROUBLE CODES (DTCS) under SELF-DIAGNOSTICS. Cycle ignition. Check for DTCs. See RETRIEVING DIAGNOSTIC TROUBLE CODES (DTCS) under SELF-DIAGNOSTICS. If DTC resets, replace outside mirror switch. See SEATS - POWER article. Recheck system operation.

Each mirror position sensor is a potentiometer. As mirror is moved, resistance varies in each position sensor. During all memory functions, MMM receives input from each mirror position sensor. During memory set function, MMM stores current voltages across position sensors. During memory recall and memory exit functions, MMM moves mirrors until each position sensor voltage matches stored voltage values.

These DTCs will not set if MMM DTC B1982 or B1983 is current. Appropriate MMM DTC will set when MMM detects any sensor input voltage is out of range. If input is less than 0.25 volts, MMM will set appropriate shorted to ground DTC. If input is 4.75 volts or more, MMM will set appropriate shorted to voltage DTC.

When DTC is set, MMM will disable suspect motor during memory recall and easy exit functions. Motor can be enabled during manual positioning. DTC will clear when MMM does not detect switch failure during last monitoring cycle.

1. If multiple position sensor DTCs are set, check for open or short in circuit No. 934 (Light Green/Black wire) between outside mirror and MMM. Check for open in circuit No. 939 (Red/Black wire) between outside mirror and MMM. Repair as necessary.
2. If only one DTC is set, check appropriate wire between position sensor in outside mirror and MMM. If circuit is okay, replace position sensor. Recheck system operation.

MMM DTC U1064: LOSS OF SERIAL COMMUNICATIONS (PZM)

Note. Platform Zone Module (PZM) may also be referred to as Body Control Module (BCM).

When ignition switch is in RUN position, all modules that communicate over the class 2 serial data bus send a State Of Health (SOH) message every 5 seconds to ensure system is operating properly. DTC will not set if MMM DTC B1982, B1983 or U1300 is current. MMM DTC U1064 will set when MMM does not receive an SOH message from PZM after 3 consecutive monitoring cycles. MMM DTC U1064 will clear when MMM detects an SOH message from PZM, conditions for setting DTC no longer exists or upon every power mode initialization.

Note. To identify circuit and components on class 2 serial data line, see appropriate wiring diagram in DATA LINK CONNECTORS article in WIRING DIAGRAMS.

1. MMM DTC U1064 does not necessarily represent an MMM failure. If DTCs are history, check each module on class 2 data line before diagnosing class 2 data line.
2. Clear all DTCs. See «CLEARING DIAGNOSTIC TROUBLE CODES (DTCS)»(/cadillac/eldorado/x-1992-2002/remont/memory-modules/#memory-system__clearing-diagnostic-trouble-codes-dtcs) under SELF-DIAGNOSTICS. Cycle ignition. Check for DTCs. See «RETRIEVING DIAGNOSTIC TROUBLE CODES (DTCS)»(/cadillac/eldorado/x-1992-2002/remont/memory-modules/#memory-system__retrieving-diagnostic-trouble-codes-dtcs) under SELF-DIAGNOSTICS. If no DTCs exists, recheck system operation.
3. If multiple DTCs exist, check for intermittent short to ground in circuit No. 1807 (Purple wire) between MMM and other modules on class 2 serial data line.
4. If DTC is current, use scan tool to establish communication with PZM. If communication cannot be established, see «BODY CONTROL MODULE»(/cadillac/eldorado/x-1992-2002/remont/body-cab-control-systems/#body-control-module) article. If communication can be established, replace MMM.
5. If DTC is history, check for intermittent open in circuit No. 1807 (Purple wire) between MMM and other modules on class 2 serial data line.

When ignition switch is in RUN position, all modules that communicate over the class 2 serial data bus send a State Of Health (SOH) message every 5 seconds to ensure system is operating properly. DTC will not set if MMM DTC B1982, B1983 or U1300 is current. MMM DTC U1128 will set when MMM does not receive an SOH message from IRC after 3 consecutive monitoring cycles. MMM DTC U1128 will clear when MMM detects an SOH message from IRC, conditions for setting DTC no longer exists or upon every power mode initialization.

Note. To identify circuit and components on class 2 serial data line, see appropriate wiring diagram in DATA LINK CONNECTORS article in WIRING DIAGRAMS.

1. MMM DTC U1128 does not necessarily represent an MMM failure. If DTCs are history, check each module on class 2 data line before diagnosing class 2 data line.
2. Clear all DTCs. See «CLEARING DIAGNOSTIC TROUBLE CODES (DTCS)»(/cadillac/eldorado/x-1992-2002/remont/memory-modules/#memory-system__clearing-diagnostic-trouble-codes-dtcs) under SELF-DIAGNOSTICS. Cycle ignition. Check for DTCs. See «RETRIEVING DIAGNOSTIC TROUBLE CODES (DTCS)»(/cadillac/eldorado/x-1992-2002/remont/memory-modules/#memory-system__retrieving-diagnostic-trouble-codes-dtcs) under SELF-DIAGNOSTICS. If no DTCs exists, recheck system operation.
3. If multiple DTCs exist, check for intermittent short to ground in circuit No. 1807 (Purple wire) between MMM and other modules on class 2 serial data line.
4. If DTC is current, use scan tool to establish communication with IRC. If communication cannot be established, locate and repair problem in class 2 serial data line circuits between audio system and MMM. See appropriate wiring diagram in DATA LINK CONNECTORS article in WIRING DIAGRAMS. If communication can be established, replace MMM.
5. If DTC is history, check for intermittent open in circuit No. 1807 (Purple wire) between MMM and other modules on class 2 serial data line.

When ignition switch is in RUN position, all modules that communicate over the class 2 serial data bus send a State Of Health (SOH) message every 5 seconds to ensure system is operating properly.

DTC will not set if MMM DTC B1982, B1983 or U1300 is current. MMM DTC U1255 will set when MMM requests a message for initialization and the following criteria is met: Request is not acknowledged after all message retries are sent out, requested information contains an internal failsoft value, and the source ID with desired information is not known. MMM DTC U1255 will clear when conditions for setting DTC no longer exists or upon every power mode initialization.

Note. To identify circuit and components on class 2 serial data line, see appropriate wiring diagram in DATA LINK CONNECTORS article in WIRING DIAGRAMS.

1. MMM DTC U1255 does not necessarily represent an MMM failure. If DTCs are history, check each module on class 2 data line before diagnosing class 2 data line.
2. If multiple DTCs exist, check for intermittent short to ground in circuit No. 1807 (Purple wire) between MMM and other modules on class 2 serial data line. If DTC is history, check for intermittent open in circuit No. 1807 (Purple wire) between MMM and other modules on class 2 serial data line.
3. Clear all DTCs. See «CLEARING DIAGNOSTIC TROUBLE CODES (DTCS)»(/cadillac/eldorado/x-1992-2002/remont/memory-modules/#memory-system__clearing-diagnostic-trouble-codes-dtcs) under SELF-DIAGNOSTICS. Cycle ignition. Check for DTCs. See «RETRIEVING DIAGNOSTIC TROUBLE CODES (DTCS)»(/cadillac/eldorado/x-1992-2002/remont/memory-modules/#memory-system__retrieving-diagnostic-trouble-codes-dtcs) under SELF-DIAGNOSTICS. If MMM DTC U1255 is current, ensure all modules on class 2 serial data line are functioning properly. Check for short to ground or voltage in circuit No. 1807 (Purple wire) between MMM and other modules on class 2 serial data line. Check for poor connections at MMM. If components, circuit and connections are okay, replace MMM.

MMM DTC U1300: CLASS 2 SHORTED TO GROUND/VOLTAGE

Note. Platform Zone Module (PZM) may also be referred to as Body Control Module (BCM).

When ignition switch is in RUN position, all modules that communicate over the class 2 serial data bus send a State Of Health (SOH) message every 5 seconds to ensure system is operating properly. DTC will not set if MMM DTC B1982 or B1983 is current. MMM DTC U1300 will set when MMM detects that class 2 serial data line is shorted to ground or voltage for at least 3 seconds. MMM DTC U1300 will clear when conditions for setting DTC no longer exist.

Note. To identify circuit and components on class 2 serial data line, see appropriate wiring diagram in DATA LINK CONNECTORS article in WIRING DIAGRAMS.

MMM DTC U1300 cannot be received as current, as class 2 bus will not function during this condition. See BODY CONTROL MODULE article.

REMOVAL & INSTALLATION

Note. For removal and installation procedures, see SEATS - POWER or POWER MIRRORS article.

Memory Power Seats/Power Mirrors Wiring Diagram (Concours & DeVille - 1 Of 2). Scheme 1

Memory Power Seats/Power Mirrors Wiring Diagram (Concours & DeVille - 2 Of 2). Scheme 2

Memory Power Seats/Power Mirrors Wiring Diagram (Eldorado & Seville - 1 Of 2). Scheme 3

See also:
• SEATS - POWER
• MIRRORS - POWER
• KEYLESS ENTRY SYSTEM - REMOTE
• GENERATOR & REGULATOR
• BODY CONTROL MODULE
• RETRIEVING DIAGNOSTIC TROUBLE CODES (DTCS)
• PRELIMINARY CHECKS
• LEFT SEAT DOES NOT MANUALLY MOVE IN ANY DIRECTION
• LEFT LUMBAR SUPPORT DOES NOT MANUALLY MOVE IN ANY DIRECTION
• DIAGNOSTIC SYSTEM CHECK
• CLEARING DIAGNOSTIC TROUBLE CODES (DTCS)
• U1064
• U1300
• U1064
• U1300
• DIAGNOSTIC TROUBLE CODES (DTCS)