Power Seat System Cadillac DeVille Concours

SYSTEM DESCRIPTION

Power seats operate using toggle switches located on seat side or in door arm rest. Seat adjusters are powered by a 12-volt, reversible motor with an internal circuit breaker. A 30-amp, plug-in circuit breaker, located in fuse panel, protects power seat wiring. On some models, seats are available with heating and memory options.

6-WAY POWER SEATS

Power seats use 3 reversible motors that operate seat functions. Front and back parts of seat are operated by different motors, and can be raised and lowered independently. Third motor controls forward/backward movement. Drive cables connect motor to gearnuts, which turn jack screws and adjusters at each side of seat.

POWER RECLINING SEATBACK

System includes an under-seat motor, drive cable, actuator and control switch. Switch is on seat edge. Power seat back recliners operate independently of other power seat adjustments.

SPORT LUMBAR SEATS

Sport lumbar seat is an option on some models. Power is supplied by a 30-amp circuit breaker in fuse block. Adjustments are made by up/down or fore/aft lumbar relays located in seatback. Operation is controlled by a switch located on seat side or in center console.

HORIZONTAL ACTUATOR

1. Chucking can be corrected by adjusting horizontal actuator and pinion gear to fully mesh with lower adjuster track rack gear. Operate seat to full up position and about 3/4 forward. Loosen horizontal actuator attaching screws. (Scheme 1)
2. Using a large screwdriver, apply outward pressure on horizontal actuator (about 15-25 ft. lbs.) and energize horizontal switch to move seat slightly fore and aft. This keeps seat horizontal actuator pinion gear teeth in close contact with lower track rack gear teeth and eliminates free play between gear teeth. Tighten screws while maintaining outward pressure against horizontal actuators.

Scheme 1

SEAT ADJUSTER PHASING

When installing power seat adjusters (except at back recliner), ensure each pair of adjusters is in phase. When adjusters are out of phase, one adjuster will reach its maximum travel limit before the other, resulting in improper seat travel.

Horizontal Travel

Operate seat until one adjuster reaches full forward position. Detach horizontal drive cable from adjuster which has reached its travel limit. Operate seat forward until other adjuster reaches its full forward position. Reconnect drive cable of first adjuster. Adjusters are now in phase.

Vertical Travel (Front Or Rear)

1. Operate seat until one adjuster has reached fully raised position at both front and rear vertical travel limits. Disconnect both front and rear vertical drive cables from adjuster which has reached its travel limit.
2. Operate seat until other adjuster reaches fully raised position. Reconnect previously disconnected front and rear vertical drive cables. Seat adjusters should be in phase. If not, repeat procedure.

PRELIMINARY CHECKS

1. If power accessory circuit breaker opens whenever power seat switch is operated, check circuits for a short to ground. Check for proper installation of aftermarket electronic equipment.
2. 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. Check by monitoring for voltage drop with system under load.

Jerky Horizontal Operation

Check for improper lubrication of adjuster shoes and channels. Check for horizontal actuator-to-rack gear adjusted too tight. See HORIZONTAL ACTUATOR under ADJUSTMENTS.

Horizontal Chuck Or Looseness

Check for horizontal actuator improperly adjusted. See HORIZONTAL ACTUATOR under ADJUSTMENTS.

One Adjuster Will Not Operate Horizontally

Check for disconnected or damaged horizontal drive cable. Check for inoperative horizontal actuator.

One Adjuster Will Not Operate Vertically

Check for disconnected or damaged vertical drive cable. Check vertical gearnut inoperation. Replace vertical actuator assembly if necessary.

Entire Seat Will Not Go Forward Or Back (Up & Down Functions Operate Normally)

1) Turn ignition off. At inoperative seat, disconnect power seat switch. Disconnect forward/back motor connector. Using ohmmeter, check resistance of Light Green wire between power seat switch and forward/back motor. If resistance is 5 ohms or less, go to next step. If resistance is not 5 ohms or less, check for poor connection or open in Light Green wire. If circuit is okay, replace power seat switch.

2) Check resistance of Tan wire between power seat switch and forward/back motor. If resistance is 5 ohms or less, replace forward/back motor. If resistance is not 5 ohms or less, check for poor connection or open in Tan wire. If circuit is okay, replace power seat switch.

Front Height Will Not Go Up Or Down

1. Turn ignition off. At inoperative seat, disconnect power seat switch. Disconnect front height motor connector. Using ohmmeter, check resistance of Dark Green wire between power seat switch and front height motor. If resistance is 5 ohms or less, go to next step. If resistance is not 5 ohms or less, check for open in Dark Green wire. If circuit is okay, replace power seat switch.
2. Check resistance of Dark Blue wire between power seat switch and front height motor. If resistance is 5 ohms or less, replace front height motor. If resistance is not 5 ohms or less, check for open in Dark Blue wire. If circuit is okay, replace power seat switch.

Rear Height Will Not Go Up Or Down

1. Turn ignition off. At inoperative seat, disconnect power seat switch. Disconnect rear height motor connector. Using ohmmeter, check resistance of Yellow wire between power seat switch and rear height motor. If resistance is 5 ohms or less, go to next step. If resistance is not 5 ohms or less, check for open in Yellow wire. If circuit is okay, replace power seat switch.
2. Check resistance of Light Blue wire between power seat switch and rear height motor. If resistance is 5 ohms or less, replace rear height motor. If resistance is not 5 ohms or less, check for open in Light Blue wire. If circuit is okay, replace power seat switch.

HEATED SEATS

To diagnose heated seats, perform indicated test. See HEATED SEAT DIAGNOSIS table.

HEATED SEAT DIAGNOSIS

Test No. 1, Driver's Heated Seat Switch Indicator On Continuously (Concours & DeVille)

1. Disconnect driver's heated seat switch connector C1. See «WIRING DIAGRAMS»(/cadillac/deville-concours/1994-1998/remont/seats/#power-seat-system) . Using voltmeter, check voltage between heated seat switch connector C1 harness terminal "C" (Dark Blue wire) and ground. If battery voltage exists, go to next step. If battery voltage does not exist, replace driver's heated seat switch.
2. Disconnect driver's heated seat relay module. Check voltage between heated seat switch connector C1 harness terminal "C" (Dark Blue wire) and ground. If battery voltage exists, repair short to power in Dark Blue wire. If battery voltage does not exist, replace driver's heated seat relay module.

Test No. 1, Driver's Heated Seat Switch Indicator On Continuously (Seville)

1. Disconnect console switch connector C1. See «WIRING DIAGRAMS»(/cadillac/deville-concours/1994-1998/remont/seats/#power-seat-system) . Using voltmeter, check voltage between console switch connector C1 harness terminal No. 3 (Light Blue wire) and ground. If battery voltage exists, go to next step. If battery voltage does not exist, replace console switch.
2. Disconnect driver's heated seat relay module. Check voltage between console switch connector C1 harness terminal No. 3 (Light Blue wire) and ground. If battery voltage exists, repair short to power in Light Blue wire. If battery voltage does not exist, replace driver's heated seat relay module.

Test No. 2, Passenger's Heated Seat Switch Indicator On Continuously (Concours & DeVille)

1. Disconnect passenger's heated seat switch connector C2. See «WIRING DIAGRAMS»(/cadillac/deville-concours/1994-1998/remont/seats/#power-seat-system) . Using voltmeter, check voltage between heated seat switch connector C2 harness terminal "C" (Dark Blue wire) and ground. If battery voltage exists, go to next step. If battery voltage does not exist, replace passenger's heated seat switch.
2. Disconnect passenger's heated seat relay module. Check voltage between heated seat switch connector C2 harness terminal "C" (Dark Blue wire) and ground. If battery voltage exists, repair short to power in Dark Blue wire. If battery voltage does not exist, replace passenger's heated seat relay module.

Test No. 2, Passenger's Heated Seat Switch Indicator On Continuously (Seville)

1. Disconnect console switch connector C2. See «WIRING DIAGRAMS»(/cadillac/deville-concours/1994-1998/remont/seats/#power-seat-system) . Using voltmeter, check voltage between console switch connector C2 harness terminal No. 3 (Light Blue/Black wire) and ground. If battery voltage exists, go to next step. If battery voltage does not exist, replace console switch.
2. Disconnect passenger's heated seat relay module. Check voltage between console switch connector C2 harness terminal No. 3 (Light Blue/Black wire) and ground. If battery voltage exists, repair short to power in Light Blue/Black wire. If battery voltage does not exist, replace passenger's heated seat relay module.

Test No. 3, Driver's Heated Seat Shorted To Battery (Concours & DeVille)

1. Disconnect driver's heated seat switch connector. Using voltmeter, check voltage between heated seat switch connector harness terminal "D" (Brown wire) and ground. If battery voltage exists, go to next step. If battery voltage does not exist, go to step 3 .
2. Remove CONSOLE fuse (10-amp) from trunk compartment fuse block. Check voltage between heated seat switch connector harness terminal "D" (Brown wire) and ground. If battery voltage exists, repair short to power in Brown wire. If battery voltage does not exist, check for short to power in Orange wire between CONSOLE fuse and ignition switch.
3. Check voltage between heated seat switch connector harness terminal "B" (Pink wire) and ground. If battery voltage exists, go to next step. If battery voltage does not exist, replace heated seat switch.
4. Disconnect driver's heated seat relay module. Check voltage between heated seat switch connector harness terminal "B" (Pink wire) and ground. If battery voltage exists, repair short to power in Pink wire between heated seat switch and heated seat relay module. If battery voltage does not exist, replace heated seat relay module.

Test No. 3, Driver's Heated Seat Shorted To Battery (Seville)

1. Disconnect console switch connector C1. See «WIRING DIAGRAMS»(/cadillac/deville-concours/1994-1998/remont/seats/#power-seat-system) . Using voltmeter, check voltage between console switch connector C1 harness terminal No. 5 (Brown wire) and ground. If battery voltage exists, go to next step. If battery voltage does not exist, go to step 4 .
2. Remove CONSOLE fuse (10-amp) from trunk compartment fuse block. Check voltage between console switch connector C1 harness terminal No. 5 (Brown wire) and ground. If battery voltage exists, repair short to power in Brown wire. If battery voltage does not exist, check for short to power in Orange wire between CONSOLE fuse and ignition switch.
3. Check voltage between console switch connector C1 harness terminal No. 1 (Pink wire) and ground. If battery voltage exists, go to next step. If battery voltage does not exist, replace console switch.
4. Disconnect driver's heated seat relay module. Check voltage between console switch connector C1 harness terminal No. 1 (Pink wire) and ground. If battery voltage exists, repair short to power in Pink wire between console switch and heated seat relay module. If battery voltage does not exist, replace heated seat relay module.

Test No. 4, Passenger's Heated Seat Shorted To Battery (Concours & DeVille)

1. Disconnect heated seat switch connector. Using voltmeter, check voltage between heated seat switch connector harness terminal "B" (Pink wire) and ground. If battery voltage exists, go to next step. If battery voltage does not exist, replace heated seat switch.
2. Disconnect heated seat relay module. Check voltage between heated seat switch connector harness terminal "B" (Pink wire) and ground. If battery voltage exists, repair short to power in Pink wire. If battery voltage does not exist, replace heated seat relay module.

Test No. 4, Passenger's Heated Seat Shorted To Battery (Seville)

1. Disconnect console switch connector C2. See «WIRING DIAGRAMS»(/cadillac/deville-concours/1994-1998/remont/seats/#power-seat-system) . Using voltmeter, check voltage between console switch connector C2 harness terminal No. 1 (Pink/Black wire) and ground. If battery voltage exists, go to next step. If battery voltage does not exist, replace heated seat switch.
2. Disconnect heated seat relay module. Check voltage between console switch connector C2 harness terminal No. 1 (Pink/Black wire) and ground. If battery voltage exists, repair short to power in Pink/Black wire. If battery voltage does not exist, replace heated seat relay module.

Test No. 5, Seat Heats Continuously

1. If only seatback heats continuously, go to next step. If both seatback and seat cushion heat continuously, go to step 3).
2. Disconnect seatback connector C2. Using voltmeter, check voltage between seatback connector C2 harness terminal "A" (Brown wire) and ground. If reading is zero volts, repair short to power in seatback heating element. If reading is not zero volts, check for short to power in Brown wire between seatback and seat cushion. If circuit is okay, replace seat cushion heating element.
3. Disconnect heated seat relay module at inoperative seat. If seat is still heating, go to next step. If seat is not still heating, replace heated seat relay module.
4. Disconnect seat cushion connector C1. Check voltage between heated seat relay module harness terminal "A" (Red/White wire) and ground. If reading is zero volts, repair short to power in seat cushion heating element. If reading is not zero volts, repair short to voltage in Red/White wire between heated seat relay module and seat cushion.

Test No. 6, Seat Only Partially Heats

1. Disconnect heated seat relay module. Disconnect seatback connector C2. Disconnect seat cushion connector C1. Using ohmmeter, check resistance between seat cushion connector C1 terminal "B" (Brown wire) and ground. If resistance is more than 100 k/ohms, go to next step. If resistance is not more than 100 k/ohms, repair short to ground in seat cushion heating element.
2. Check resistance between seat cushion connector C1 harness terminal "B" (Brown wire) and ground. If resistance is not more than 100 k/ohms, repair short to ground in Brown wire between seat cushion and seatback. If resistance is more than 100 k/ohms, repair short to ground in seat cushion heating element.

Test No. 7, Heated Seat Switch Does Not Come On (Concours & DeVille)

Turn ignition off. Disconnect heated seat switch connector at inoperative seat. Using ohmmeter, check resistance between heated seat switch connector harness terminal "A" (Black wire) and ground. If resistance is one ohm or less, replace heated seat switch. If resistance is not one ohm or less, repair open in Black wire.

Test No. 7, Heated Seat Switch Does Not Come On (Seville)

Turn ignition off. Disconnect console switch connector C1 (driver's seat) or C2 (passenger's seat). Using ohmmeter, check resistance between console switch connector harness terminal No. 2 (Black wire) and ground. If resistance is one ohm or less, replace console switch. If resistance is not one ohm or less, repair open in Black wire.

Driver's Seat Switch Isolation

1. Turn ignition off. Ground memory seat module diagnostic connector (located under driver's seat) to enter Mode 1 diagnostics. Operate power seat switch until a beep is heard. This ensures that memory seat module and Mode 1 diagnostics are activated. During Mode 1 diagnostics, all seat and recliner motions are disabled.
2. If beep was heard in step 1), go to next step. If beep was not heard in step 1), ensure battery voltage exists at memory seat module connector C1 terminal No. 3 (Orange wire) and connector C2 terminal "A" (Red wire). Repair as necessary. If battery voltage exists as indicated, repair poor ground connection at memory seat module diagnostic connector.
3. Operate driver's power seat switch and recliner switch in all positions that do not work. If memory seat module beeps once for each switch position, go to step 5). If memory seat module does not beep once for each switch position, go to next step.
4. With inoperative switch position pressed, use ohmmeter to check resistance between appropriate memory seat module terminal and chassis ground. See «WIRING DIAGRAMS»(/cadillac/deville-concours/1994-1998/remont/seats/#power-seat-system) . If resistance is less than one ohm, replace memory seat module. If resistance is greater than one ohm, replace driver's seat switch.
5. Disconnect inoperative motor. Apply battery voltage to one motor terminal, and ground other motor terminal. If motor operates, check for poor connection, open, or short to ground in circuits to motor. If circuits are okay, replace memory seat module. If motor does not operate, check cables and linkage for binding. If cables and linkage are okay, replace motor.

Memory Switch Isolation

1. Turn ignition off. Ground memory seat module diagnostic connector (located under driver's seat) to enter Mode 1 diagnostics. Operate power seat switch until a beep is heard. This ensures that memory seat module and Mode 1 diagnostics are activated. During Mode 1 diagnostics, all seat and recliner motions are disabled.
2. If beep was heard in step 1), go to next step. If beep was not heard in step 1), ensure battery voltage exists at memory seat module connector C1 terminal No. 3 (Orange wire) and connector C2 terminal "A" (Red wire). Repair as necessary. If battery voltage exists as indicated, repair poor ground connection at memory seat module diagnostic connector.
3. Operate all seat memory switches (memory 1, memory 2, set memory and exit). If memory seat module beeps once for each switch position, go to POSITION SENSOR ISOLATION. If memory seat module does not beep once for each switch position, go to next step.
4. If memory seat module beeped at some switch positions, go to next step. If memory seat module did not beep for any switch position, check for reference voltage at each memory seat switch terminal. Check for poor connections at memory seat module. If voltage and connections are okay, replace memory seat module.
5. With inoperative switch position pressed, use ohmmeter to check resistance between appropriate memory seat module terminal and chassis ground. See «WIRING DIAGRAMS»(/cadillac/deville-concours/1994-1998/remont/seats/#power-seat-system) . If resistance is less than one ohm, replace memory seat module. If resistance is greater than one ohm, replace memory seat switch.

Position Sensor Isolation

1. Enter Mode 2 diagnostics by removing ground from memory seat module diagnostic connector, then regrounding the connector within 5 seconds. Seat memory module should beep twice to confirm Mode 2 diagnostics is activated. During Mode 2 diagnostics, all seat and recliner motions are enabled.
2. Move seat from full stop to full stop in each direction. If memory seat module beeps twice a second while seat is operated, go to next step. If memory seat module does not beep twice a second while seat is operated, go to step 5).
3. If memory seat module beeps during one motor function only, go to next step. If memory seat module beeps in all directions, check for open or short to ground in Gray wire to position sensors. Check for open in Black wire to position sensors. If circuits are okay, replace memory seat module.
4. At inoperative position sensor, check for 5 volts to ground on Gray wire with driver's seat switch activated. Check for less than one ohm of resistance in wire between position sensor and memory seat module. See «WIRING DIAGRAMS»(/cadillac/deville-concours/1994-1998/remont/seats/#power-seat-system) . Check for zero volts in Black wire to chassis ground with driver's seat switch activated. If voltages and resistances are okay, replace inoperative position sensor.
5. If one beep is heard when seat passes a certain point, check for poor contacts between suspect position sensor and memory seat module. If connections are okay, replace position sensor. If one beep is not heard when seat passes a certain point, verify symptom still exists. Perform POSITION SENSOR ISOLATION test again. If symptom still exists, replace memory seat module.

All Recliner Functions Inoperative

Check for open or short to ground in Red wire between inoperative recliner switch and fuse block. Check for open in Black wire between inoperative recliner switch and ground. Repair as necessary.

Power/Grounding Diagnosis

1. Operate recliner switch in recline back, then recline forward position. Check SEATS circuit breaker (30-amp) located in LH Maxi fuse block. If circuit breaker is closed, go to next step. If circuit breaker is open, see POWER CIRCUIT BREAKER TRIPS DIAGNOSIS.
2. Using voltmeter, check for voltage at Red wire terminal of both driver's and passenger's recliner switches. If voltage exists, check Black wire between recliner switches and ground. If voltage does not exist, repair open in Red wire between recliner switch and fuse block.

Power Circuit Breaker Trips Diagnosis

1. Check SEATS circuit breaker (30-amp) located in LH Maxi fuse block. If circuit breaker is closed, go to next step. If circuit breaker is open, check for short to ground in Red wire between recliner switch and fuse block. Check for short to ground in position sensor(s) circuits. Repair as necessary.
2. Move driver's seat recliner switch to recline, then forward position. Move passenger's seat recliner switch to recline, then forward position. If circuit breaker is open, go to MOTOR SHORT DIAGNOSIS. If circuit breaker is not open, check system for an intermittent short. Repair as necessary.

Motor Short Diagnosis

1. Disconnect SEATS circuit breaker (30-amp) located in LH Maxi fuse block. If seat fails to move to recline position, disconnect Light Blue wire from appropriate recliner switch and recliner motor. If seat fails to move to forward position, disconnect Light Green wire from appropriate recliner switch and recliner motor. Using ohmmeter, check resistance between ground and Light Blue or Light Green wire. If high resistance exists, go to next step. If high resistance does not exist, repair short to ground in Light Blue or Light Green wire.
2. Check resistance between ground and Black wire terminal(s) of driver's recliner switch. Check resistance between ground and Black wire terminal(s) of passenger's recliner switch. If recliner switches have a high resistance, go to next step. If recliner switches do not have a high resistance, replace appropriate recliner switch.
3. With ohmmeter attached between ground and Black wire terminal(s) of driver's recliner switch, move recliner switch to both recline and forward positions. With ohmmeter attached between ground and Black wire terminal(s) of passenger's recliner switch, move recliner switch to both recline and forward positions. If high resistance exists when switch is actuated, replace appropriate recliner seat motor. If high resistance does not exist when switch is actuated, replace appropriate recliner switch.

Recliner Seat Failure Diagnosis

1. Using voltmeter, check for voltage at Red wire terminal of inoperative recliner switch. If voltage exists, go to next step. If voltage does not exist, repair open in Red wire between inoperative recliner switch and fuse block.
2. Check for voltage between ground and Black wire terminal(s) of inoperative recliner switch. If voltage does not exist, go to next step. If voltage exists, replace recliner switch.
3. Using ohmmeter, check continuity of Black wire(s) between inoperative recliner switch and ground terminal. If continuity exists, go to next step. If continuity does not exist, check for open in Black wire(s) between inoperative recliner switch and ground. Check for poor connection at ground. Repair as necessary.
4. Check continuity of Light Blue and Light Green wires between inoperative recliner switch and recliner motor. If continuity exists in both wires, go to next step. If continuity does not exist in both wires, repair open in appropriate wire between inoperative recliner switch and recliner motor.
5. Move inoperative recliner switch to recline position. Using voltmeter, check for voltage at Light Blue wire terminal of inoperative recliner switch. If voltage exists, go to next step. If voltage does not exist, replace recliner switch.
6. Move inoperative recliner switch to forward position. Check for voltage at Light Green wire terminal of inoperative recliner switch. If voltage exists, go to next step. If voltage does not exist, replace inoperative recliner switch.
7. On Concours and DeVille, use ohmmeter to check continuity between inoperative recliner switch terminals "B" (Light Blue wire) and "C" (Black wire). Check continuity between inoperative recliner switch terminals "E" (Light Green wire) and "F" (Black wire). If continuity exists, replace recliner motor. If continuity does not exist, replace recliner switch.
8. On Seville, use ohmmeter to check continuity between Light Blue and Black wire terminals of inoperative recliner switch. Check continuity between Light Green wire and Black wire terminals of inoperative recliner switch. If continuity exists, replace recliner motor. If continuity does not exist, replace recliner switch.

Recline Forward Mode Inoperative; Recline Back Mode Operates Normally

On Concours and DeVille, check for open in Black wire(s) between inoperative recliner switch and splice. If circuits are okay, replace inoperative recliner switch. On Seville, replace inoperative recliner switch.

Recline Back Mode Inoperative; Recline Forward Mode Operates Normally

On Concours and DeVille, check for open in Black wire(s) between inoperative recliner switch and splice. If circuits are okay, replace inoperative recliner switch. On Seville, replace inoperative recliner switch.

POWER LUMBAR SEATS

To diagnose power lumbar seats, perform indicated test. See POWER LUMBAR SEAT DIAGNOSIS table.

POWER LUMBAR SEAT DIAGNOSIS

Test No. 1, Power/Grounding Diagnosis

1. Operate driver's lumbar switch in up/down positions, then fore/aft positions. Check SEATS circuit breaker (30-amp) located in LH Maxi fuse block. If circuit breaker is closed, go to next step. If circuit breaker is open, see TEST NO. 2, POWER CIRCUIT BREAKER TRIPS DIAGNOSIS.
2. Using voltmeter, check for voltage at terminal "C" (Red wire) of up/down and fore/aft lumbar relays at each seat. If voltage exists, go to next step. If voltage does not exist, repair open in Red wire between appropriate lumbar relay and fuse block.
3. Check BATT fuse (10-amp) located in trunk compartment fuse block. If fuse is okay, go to next step. If fuse is blown, go to TEST NO. 4, CONTROL CIRCUIT FUSE BLOWS DIAGNOSIS.
4. Using voltmeter, check for voltage at Orange pigtail wire terminal of driver's lumbar switch. If voltage exists, check Black ground wire to each lumbar relay. Repair as necessary. If voltage does not exist, repair open in Orange or Orange/Black wire between driver's lumbar switch and BATT fuse.

Test No. 2, Power Circuit Breaker Trips Diagnosis

1. Remove SEATS circuit breaker (30-amp) located in LH Maxi fuse block. Disconnect wire at terminal "C" (Red wire) from up/down and fore/aft lumbar relays of each seat. Using ohmmeter, check resistance between ground and insulation of each Red wire. If high resistance exists, go to next step. If high resistance does not exist, repair short to ground in Red wire between appropriate lumbar relay and fuse block.
2. Using ohmmeter, check resistance between each up/down lumbar relay terminals "A" (Red wire) and "D" (Black wire). Check resistance between each fore/aft lumbar relay terminals "A" (Gray wire) and "D" (Black wire). If continuity does not exist, go to next step. If continuity exists, replace defective lumbar relay.
3. Reconnect Red wires to each lumbar relay. Reinstall SEATS circuit breaker. Ensure SEATS circuit breaker is not open. Using voltmeter, ensure voltage exists at each lumbar relay terminal "C" (Red wire). Move each lumbar switch to up, down, fore, then aft positions. If SEATS circuit breaker opens after any switch position has been actuated, go to TEST NO. 3, RELAY/MOTOR SHORT DIAGNOSIS. If SEATS circuit breaker does not open after any switch position has been actuated, check for intermittent short. Repair as necessary.

Test No. 3, Relay/Motor Short Diagnosis

1. Ensure SEATS circuit breaker (30-amp) located in LH Maxi fuse block is open. Disconnect both wires between inoperative lumbar relay and lumbar motor (remove from relay and motor). See «WIRING DIAGRAMS»(/cadillac/deville-concours/1994-1998/remont/seats/#power-seat-system) . Using ohmmeter, check resistance between ground and each wire between inoperative lumbar relay and lumbar motor.
2. If high resistance or open exists, replace defective lumbar motor. If high resistance or open does not exist, repair short to ground in appropriate wire between inoperative lumbar relay and lumbar motor.

Test No. 4, Control Circuit Fuse Blows Diagnosis

1. Disconnect Orange pigtail wire from lumbar switches for both seats. Replace BATT fuse (10-amp) in trunk compartment fuse block. If fuse does not blow, go to next step. If fuse blows, repair short to ground in Orange or Orange/Black wire between lumbar switch and fuse block. Replace BATT fuse.
2. Reconnect Orange pigtail wire to lumbar switch for driver's seat. If fuse does not blow, go to next step. If fuse blows, replace driver's seat lumbar switch. Replace BATT fuse.
3. Reconnect Orange pigtail wire to lumbar switch for passenger's seat. If fuse does not blow, go to next step. If fuse blows, replace passenger's seat lumbar switch. Replace BATT fuse.
4. Operate each lumbar switch position at each seat. If fuse does not blow when any switch position is operated, check for intermittent short. Repair as necessary. If fuse blows when a switch position is operated, record which switch position caused fuse to blow. Go to TEST NO. 5, SWITCH/RELAY CONTROL POWER SHORT DIAGNOSIS.

Test No. 5, Switch/Relay Control Power Short Diagnosis

1. Remove blown BATT fuse from trunk compartment fuse block. If fuse blew in up position, disconnect Red wire from appropriate lumbar switch and up/down lumbar relay. If fuse blew in down position, disconnect Yellow wire from appropriate lumbar switch and up/down lumbar relay. If fuse blew in fore position, disconnect Purple wire from appropriate lumbar switch and fore/aft lumbar relay. If fuse blew in aft position, disconnect Gray wire from appropriate lumbar switch and fore/aft lumbar relay.
2. Using ohmmeter, check for continuity between appropriate terminal at lumbar switch and ground. If continuity does not exist, go to next step. If continuity exists, replace defective lumbar switch. Replace BATT fuse.
3. Check resistance between disconnected wire and ground. If high resistance exists, go to next step. If high resistance does not exist, repair short to ground in appropriate wire between lumbar switch and lumbar relay.
4. Check resistance between appropriate terminal and Black wire terminal at lumbar relay. If resistance exists, check for intermittent short. Repair as necessary. If resistance does not exist, replace defective lumbar relay.

Test No. 6, Up/Down Failure Diagnosis

1. Using voltmeter, check for voltage at up/down lumbar relay terminal "C" (Red wire) at inoperative seat. If voltage exists, go to next step. If voltage does not exist, repair open in Red wire between up/down lumbar relay and splice No. 352 (located in driver's seat harness, about 38 cm from seat switch connector).
2. Check for voltage at up/down lumbar relay terminal "A" (Red wire) at inoperative seat. Check for voltage at up/down lumbar relay terminal "F" (Yellow wire) at inoperative seat. If voltage does not exist at both terminals, go to next step. If voltage exists at either terminal, replace defective lumbar switch.
3. Using ohmmeter, check continuity of Black wire between appropriate up/down lumbar relay and ground. If continuity exists, go to next step. If continuity does not exist, repair open in Black wire.
4. Using voltmeter, ensure no voltage exists at terminal "B" or "E" of appropriate up/down lumbar relay. See «WIRING DIAGRAMS»(/cadillac/deville-concours/1994-1998/remont/seats/#power-seat-system) . Using ohmmeter, check for continuity between terminals "E" and "D" at appropriate up/down lumbar relay. If continuity exists, go to next step. If continuity does not exist, replace up/down lumbar relay.
5. Check for continuity between terminals "B" and "D" at appropriate up/down lumbar relay. If continuity exists, go to next step. If continuity does not exist, replace up/down lumbar relay.
6. Check each wire between appropriate up/down lumbar relay and up/down lumbar motor for continuity. If continuity exists in both wires, go to next step. If continuity does not exist in both wires, repair open circuit in appropriate wire.
7. Move lumbar switch to up position. Using voltmeter, check voltage at terminal "A" of appropriate up/down lumbar motor. See «WIRING DIAGRAMS»(/cadillac/deville-concours/1994-1998/remont/seats/#power-seat-system) . If voltage does not exist, go to next step. If voltage exists, replace up/down lumbar motor.
8. Move lumbar switch to up position. Check voltage at terminal "A" (Red wire) of appropriate up/down lumbar relay. If voltage does not exist, go to next step. If voltage exists, replace up/down lumbar relay.
9. Move lumbar switch to up position. Check voltage at Red wire terminal of appropriate lumbar switch. If voltage exists, go to next step. If voltage does not exist, replace lumbar switch.
10. Using ohmmeter, check for continuity in Red wire between appropriate lumbar switch and up/down lumbar relay. If continuity exists, go to next step. If continuity does not exist, repair open in Red wire.
11. Move lumbar switch to down position. Using voltmeter, check voltage at terminal "B" of appropriate up/down lumbar motor. See «WIRING DIAGRAMS»(/cadillac/deville-concours/1994-1998/remont/seats/#power-seat-system) . If voltage does not exist, go to next step. If voltage exists, replace up/down lumbar motor.
12. Move lumbar switch to down position. Check voltage at terminal "F" (Yellow wire) of appropriate up/down lumbar relay. If voltage does not exist, go to next step. If voltage exists, replace up/down lumbar relay.
13. Move lumbar switch to down position. Check voltage at Yellow wire terminal of appropriate lumbar switch. If voltage exists, repair open in Yellow wire between lumbar switch and up/down lumbar relay. If voltage does not exist, replace lumbar switch.

Test No. 7, Fore/Aft Failure Diagnosis

1. Using voltmeter, check for voltage at fore/aft lumbar relay terminal "C" (Red wire) at inoperative seat. If voltage exists, go to next step. If voltage does not exist, repair open in Red wire between fore/aft lumbar relay and splice No. 352 (located in driver's seat harness, about 38 cm from seat switch connector).
2. Check for voltage at fore/aft lumbar relay terminal "A" (Gray wire) at inoperative seat. Check for voltage at fore/aft lumbar relay terminal "F" (Purple wire) at inoperative seat. If voltage does not exist at both terminals, go to next step. If voltage exists at either terminal, replace defective lumbar switch.
3. Using ohmmeter, check continuity of Black wire between appropriate fore/aft lumbar relay and ground. If continuity exists, go to next step. If continuity does not exist, repair open in Black wire.
4. Using voltmeter, ensure no voltage exists at terminal "B" or "E" of appropriate fore/aft lumbar relay. See «WIRING DIAGRAMS»(/cadillac/deville-concours/1994-1998/remont/seats/#power-seat-system) . Using ohmmeter, check for continuity between terminals "E" and "D" at appropriate fore/aft lumbar relay. If continuity exists, go to next step. If continuity does not exist, replace fore/aft lumbar relay.
5. Check for continuity between terminals "B" and "D" at appropriate fore/aft lumbar relay. If continuity exists, go to next step. If continuity does not exist, replace fore/aft lumbar relay.
6. Check each wire between appropriate fore/aft lumbar relay and fore/aft lumbar motor for continuity. If continuity exists in both wires, go to next step. If continuity does not exist in both wires, repair open circuit in appropriate wire.
7. Move lumbar switch to fore position. Using voltmeter, check voltage at terminal "B" of appropriate fore/aft lumbar motor. See «WIRING DIAGRAMS»(/cadillac/deville-concours/1994-1998/remont/seats/#power-seat-system) . If voltage does not exist, go to next step. If voltage exists, replace fore/aft lumbar motor.
8. Move lumbar switch to fore position. Check voltage at terminal "F" (Purple wire) of appropriate fore/aft lumbar relay. If voltage does not exist, go to next step. If voltage exists, replace fore/aft lumbar relay.
9. Move lumbar switch to fore position. Check voltage at Purple wire terminal of appropriate lumbar switch. If voltage exists, go to next step. If voltage does not exist, replace lumbar switch.
10. Using ohmmeter, check for continuity in Purple wire between appropriate lumbar switch and fore/aft lumbar relay. If continuity exists, go to next step. If continuity does not exist, repair open in Purple wire.
11. Move lumbar switch to aft position. Using voltmeter, check voltage at terminal "A" of appropriate fore/aft lumbar motor. See «WIRING DIAGRAMS»(/cadillac/deville-concours/1994-1998/remont/seats/#power-seat-system) . If voltage does not exist, go to next step. If voltage exists, replace fore/aft lumbar motor.
12. Move lumbar switch to aft position. Check voltage at terminal "A" (Gray wire) of appropriate fore/aft lumbar relay. If voltage does not exist, go to next step. If voltage exists, replace fore/aft lumbar relay.
13. Move lumbar switch to aft position. Check voltage at Gray wire terminal of appropriate lumbar switch. If voltage exists, repair open in Gray wire between lumbar switch and fore/aft lumbar relay. If voltage does not exist, replace lumbar switch.

Test No. 8, Rough Motion Diagnosis

1. Remove SEATS circuit breaker (30-amp) from LH maxi fuse block. Disconnect wires from terminals "B" and "E" at appropriate lumbar relay. See «WIRING DIAGRAMS»(/cadillac/deville-concours/1994-1998/remont/seats/#power-seat-system) . Connect a temporary ground connection to one of the wires, and connect a temporary power ground connection to other wire. Operate lumbar motor. Reverse temporary power and ground leads. Operate lumbar motor. If lumbar motor operates smoothly and without unusual noises, go to next step. If lumbar motor does not operate smoothly or makes unusual noises, repair or replace lumbar motor. Reinstall SEATS circuit breaker.
2. Remove temporary power and ground leads. Reconnect wires to lumbar relay. Reinstall SEATS circuit breaker. If up/down function is rough, disconnect Red and Yellow wires from appropriate lumbar switch. If fore/aft function is rough, disconnect Gray and Purple wires from appropriate lumbar switch. Connect a temporary ground connection at terminal "D" (Black wire) of appropriate lumbar relay. Connect temporary power connection to each relay wire, and operate appropriate lumbar switch.
3. If lumbar motor operates smoothly and continuously, remove temporary power and ground leads. Replace defective lumbar switch. If lumbar motor does not operate smoothly and continuously, remove temporary power and ground leads. Replace defective lumbar relay.

REMOVAL & INSTALLATION

POWER LUMBAR UNIT

Note. For removal and installation procedures for power lumbar motors, see SEAT MOTORS .

Removal & Installation (Concours & Seville)

Remove seatback cover. See SEATBACK & SEAT CUSHION COVERS. Remove 6 push-in fasteners and seat frame back cover. (Scheme 2) Disconnect power lumbar cables. Remove plastic tie straps at bottom of unit. Carefully bend clips securing lumbar unit to seatback frame. DO NOT distort clips. Remove lumbar unit. To install, reverse removal procedure.

Scheme 2

Move seat to fully forward and up positions. Remove rear anchor-to-floor pan nuts. Tilt seat forward, and disconnect electrical connectors. Using assistant, pull seat rearward and disengage seat from front retaining hooks. To install, reverse removal procedure. Check operation of seat, and adjust if necessary. See ADJUSTMENTS .

Removal & Installation (Power Seat/Memory Seat Switches Concours & DeVille)

1. Using 1/2" wide, flat-blade screwdriver, pry up on rear edge of trim panel. Insert blade 3/4" into door trim panel, and press firmly toward switch plate to disengage retention clip. Pull screwdriver upward while pressing firmly toward plate, and pull plate from trim panel. CAUTION: Ensure retention clip has been completely disengaged, or switch plate or clip may be damaged.
2. Disconnect electrical connectors. Remove switch plate. To install, connect electrical connectors. Install switch plate into trim panel evenly, and press into place until clips on both ends are engaged.

Removal & Installation (Power Recliner, Lumbar & Heated Seat Switches Concours & DeVille)

Remove seat side trim panel. Using flat-blade tool, carefully pry rear edge of switch escutcheon from trim panel. Release tabs, and remove switch from switch escutcheon. To install, reverse removal procedure.

Removal & Installation (Power Seat & Recliner Switches (Seville)

Pull switch knobs from switch. Remove screws and seat side trim panel. Disconnect electrical connector. Remove screw and seat switch. To install, reverse removal procedure.

Removal & Installation (Heated Seat & Lumbar Switches (Seville)

Open console. Remove storage bin. Disconnect electrical connectors. Using thin flat-blade screwdriver, release tabs on each side of switch, and remove switch assembly from console. To install, reverse removal procedure.

1. Remove power seat. See «POWER SEAT»(/cadillac/deville-concours/1994-1998/remont/seats/#power-seat-system) . Remove seatback assembly. See «SEATBACK ASSEMBLY»(/cadillac/deville-concours/1994-1998/remont/seats/#power-seat-system) . Disconnect seat cushion "J" retainers. Remove seat cushion cover and foam. Disconnect horizontal and vertical drive cables by squeezing oblong connector at motors, gearnuts or adjuster drives.
2. Remove memory seat module (if equipped). See «MEMORY SEAT MODULE»(/cadillac/deville-concours/1994-1998/remont/seats/#power-seat-system) . Remove seat motors. See «SEAT MOTORS»(/cadillac/deville-concours/1994-1998/remont/seats/#power-seat-system__seat-motors) . To install, reverse removal procedure. Check operation of seat, and adjust if necessary. See «ADJUSTMENTS»(/cadillac/deville-concours/1994-1998/remont/seats/#power-seat-system) .

SEAT MOTORS

Note. Removal and installation information for power lumbar motors on DeVille are not available from manufacturer.

Removal & Installation (Seat Adjuster Motors)

1. Move seat to full up position. Remove power seat. See «POWER SEAT»(/cadillac/deville-concours/1994-1998/remont/seats/#power-seat-system). Place seat upside-down on a clean surface. Disconnect electrical connectors to motors. Disconnect horizontal and vertical drive cables by squeezing oblong connector at motors, gearnuts or adjuster drives.
2. Remove nut retaining front of motor support bracket to inboard adjuster. Partially withdraw motor support bracket from adjuster and gearnut drives. Remove seat adjuster motors. (Scheme 3) To install, reverse removal procedure.

Removal & Installation (Power Lumbar Motor (Concours & Seville)

Remove seatback cover. See SEATBACK & SEAT CUSHION COVERS. Remove 6 push-in fasteners retaining seat frame back cover. Refer to Fig. (Scheme 2). Remove seat frame back cover. Remove drive cables to lumbar motor. Remove lumbar motor electrical connector. Remove 2 screws and power lumbar motor. To install, reverse removal procedure.

Removal & Installation (Power Recliner Motor)

Move seat to full up position. Remove power seat. See POWER SEAT. Place seat upside-down on a clean surface. Disconnect power recliner motor electrical connector. Disconnect horizontal and vertical drive cables by squeezing oblong connector at motors, gearnuts or adjuster drives. Remove power recliner motor. (Scheme 3) To install, reverse removal procedure.

Scheme 3

Disconnect "J" retainers at bottom of seatback cover. Remove 2 pins securing power recliner actuator to seatback hinge. Pull up seatback cover, and remove 2 seat hinge bolts and plastic bushings. Disconnect electrical connectors (if equipped). Remove seatback from cushion. To install, reverse removal procedure.

Removal & Installation (Seatback Cover)

Using Head Restraint Lock Releaser (J-39509), remove head restraint. Release "J" retainer at bottom of seatback. Remove cover and sheeting. Remove cover from frame. To install, reverse removal procedure.

Remove seatback assembly. See SEATBACK ASSEMBLY . Remove inner seat belts. Disconnect electrical connectors (if equipped). Remove seat cushion cover. To install, reverse removal procedure.

Removal & Installation (Heated Seat Coils)

If heated seat coils are malfunctioning, entire cover must be replaced. See SEATBACK & SEAT CUSHION COVERS .

Removal & Installation (Heated Seat Relay)

Move seat to full up position. Remove seat. See POWER SEAT. Place seat upside-down on a clean surface. Disconnect electrical connector. Remove heated seat relay from bracket. (Scheme 3) To install, reverse removal procedure.

Move seat to full up position. Remove seat. See POWER SEAT. Remove memory seat module screws. (Scheme 3) Disconnect electrical connector. Remove memory seat module. To install, reverse removal procedure.

Power Memory Seats Wiring Diagram (Seville). Scheme 4

Power Memory Seats Wiring Diagram (Concours & DeVille). Scheme 5

Power Lumbar Seats Wiring Diagram (Concours & Seville). Scheme 6

Power Seats Wiring Diagram (Seville). Scheme 7

Power Heated Seats Wiring Diagram (Seville). Scheme 8

Power Reclining Seats Wiring Diagram (Seville). Scheme 9

Power Seats Wiring Diagram (Concours & DeVille). Scheme 10

Power Heated Seats Wiring Diagram (Concours & DeVille). Scheme 11

Power Reclining Seats Wiring Diagram (Concours & DeVille). Scheme 12

See also:
• COMPUTER RELEARN PROCEDURES
• HORIZONTAL ACTUATOR
• WIRING DIAGRAMS
• SEAT MOTORS