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Headlights - Automatic Twilight Sentinel Buick Park Avenue II

Headlights 3 illustrations ~3009 words

DESCRIPTION

Automatic twilight sentinel determines automatic on/off control of exterior lights, and holds exterior lights on for a period of time after ignition is turned off. Automatic twilight sentinel uses reading from ambient light sensor to determine if Daytime Running Lights (DRL) or exterior lights (low beam headlights at full intensity) should be on. During daylight, high beam headlights are connected in series for DRL operation. During night, low beam headlights are turned on. Twilight sentinel also keeps lights on for a delay period of 3-180 seconds when gearshift lever is in Park, ambient light sensor reads darkness, and ignition is off.

Twilight sentinel switch cannot be turned off permanently. If moved to OFF position, it will automatically return to ON position when released. If gearshift lever is in Park and ignition is on, headlights can be cycled off by moving switch to OFF position, and then releasing. Headlights will return to automatic operation when gearshift lever is moved from Park.

OPERATION

System operates automatically whenever ignition is on, headlights are off, and twilight sentinel system is on. When turned on, system automatically turns on exterior lights at dusk. At dawn, system will turn exterior lights off.

System provides a non-adjustable 23-second delay before switching lights on or off. This prevents system from operating under sudden ambient lighting changes (such as passing through tunnels or exposure to bright lights at night).

COMPONENT LOCATIONS

ComponentLocation
Ambient Light SensorCenter Top Of Instrument Panel, In Defroster Grille
Body Control Module (BCM)Under Instrument Panel, Near Glove Box
Instrument Panel Junction Block Connectors C1, C2, C3 & C4Under Instrument Panel, Near Glove Box
Light Control Module (LCM) Connectors C1 & C2Under Instrument Panel, Left Of Steering Column
Underhood Junction Block Connectors C1 & C3Right Front Of Engine Compartment, Near Battery

COMPONENT LOCATIONS

HANDLING PRECAUTIONS

CAUTIONWhen handling Electrostatic Discharge (ESD) sensitive electronic parts (control modules), take special care to avoid damaging components.
  1. Discharge personal static electricity by momentarily touching metal grounding point on vehicle before touching electronic components.
  2. DO NOT touch terminals on components or connectors with fingers or metal tools. When unplugging connectors, DO NOT let metal tool contact any exposed terminal.
  3. NEVER jumper, ground, or use test probes on components or connectors unless specified in diagnosis. ALWAYS connect ground lead first.
  4. DO NOT remove solid-state components from protective packaging until ready for installation. Touch packaging to ground before opening.
  5. DO NOT bump or drop components. DO NOT place components on metal work bench, metal objects or electrically operated components (such as radio, TV or oscilloscope).

PRELIMINARY INSPECTION

  1. Check fuses in underhood junction block. If any fuse is open, check for short to ground in appropriate circuit. Ensure battery voltage exists at input side of each fuse. If battery voltage does not exist, see appropriate wiring diagram in POWER DISTRIBUTION article in WIRING DIAGRAMS.
  2. If one headlight is inoperative, check bulb, connections and related wiring. See appropriate wiring diagram in HEADLIGHT SYSTEMS & DAYTIME RUNNING LIGHTS article. Ensure all ground connections are clean and tight.
  3. Check for poor connections or broken wires inside of insulation which could cause an intermittent. Check for proper installation of aftermarket electronic equipment.

HEADLIGHT SYSTEM CHECK

  1. Turn ignition off. Turn headlights off. Ensure all exterior lights are off. If headlights remain on, go to «HEADLIGHTS DO NOT TURN OFF»(/buick/park-avenue/ii-1996-2002/remont/headlights/#headlights-automatic-twilight-sentinel__headlights-do-not-turn-off) under SYSTEM TESTS.
  2. Turn parking lights on. All parking lights should be illuminated. If parking lights are not illuminated, locate and repair problem in exterior lighting system. See appropriate wiring diagram in EXTERIOR LIGHTS article.
  3. Turn low beam headlights on. Both low beam headlights should illuminate and parking lights should remain illuminated. If low beams do not operate as specified, go to «LOW BEAM HEADLIGHTS INOPERATIVE»(/buick/park-avenue/ii-1996-2002/remont/headlights/#headlights-automatic-twilight-sentinel__low-beam-headlights-inoperative) under SYSTEM TESTS.
  4. Turn high beam headlights on. Headlights should switch from low beam to high beam and parking lights should remain illuminated. If high beams do not operate as specified, go to «HIGH BEAM HEADLIGHTS INOPERATIVE»(/buick/park-avenue/ii-1996-2002/remont/headlights/#headlights-automatic-twilight-sentinel__high-beam-headlights-inoperative) under SYSTEM TESTS.
  5. Turn low beam headlights on. Turn headlights off. Turn ignition switch to RUN position. Apply parking brake. Place gearshift lever in Drive. Expose ambient light sensor to sunlight or bright incandescent light. Both high beam headlights should illuminate at reduced intensity. All other exterior lights should remain off. If headlights do not operate as specified, go to «DAYTIME RUNNING LIGHTS (DRL) INOPERATIVE»(/buick/park-avenue/ii-1996-2002/remont/headlights/#headlights-automatic-twilight-sentinel__daytime-running-lights-drl-inoperative) under SYSTEM TESTS.
  6. Place gearshift lever in Park. Turn twilight sentinel on, with twilight sentinel delay in MIN position. Cover ambient light sensor. Both low beam headlights should illuminate at full intensity and all parking lights should illuminate within 30 seconds. If headlights do not operate as specified, go to «TWILIGHT SENTINEL INOPERATIVE»(/buick/park-avenue/ii-1996-2002/remont/headlights/#headlights-automatic-twilight-sentinel__twilight-sentinel-inoperative) under SYSTEM TESTS.
  7. Place twilight sentinel delay in MAX position. Turn ignition off. All exterior lights should turn off after 3 minutes. If exterior lights do not operate as specified, go to «TWILIGHT SENTINEL INOPERATIVE»(/buick/park-avenue/ii-1996-2002/remont/headlights/#headlights-automatic-twilight-sentinel__twilight-sentinel-inoperative) under SYSTEM TESTS.

SYSTEM TESTS

WARNINGBefore servicing instrument panel components on vehicles with Supplemental Inflatable Restraint (SIR) system, disable SIR system. See DISABLING & ACTIVATING AIR BAG SYSTEM in appropriate AIR BAG RESTRAINT SYSTEMS article.
CAUTIONTo prevent damage to terminals, Connector Test Adaptor Kit (J-35616-A) must be used whenever a diagnostic procedure requires checking or probing terminals.

Note. To aid in circuit identification and component location, see appropriate wiring diagram in HEADLIGHT SYSTEMS & DAYTIME RUNNING LIGHTS article. Refer to illustrations for identification of Lamp Control Module (LCM) harness connector terminals. (Scheme 1)and (Scheme 2).

HEADLIGHTS DO NOT TURN OFF

Note. Perform headlight system check before proceeding. See HEADLIGHT SYSTEM CHECK under TROUBLE SHOOTING.

  1. Turn ignition off. Disconnect headlight switch harness connector, located at left side of instrument panel. If headlights turn off, go to step 7 . If headlights do not turn off, go to next step.
  2. Disconnect headlight dimmer switch 24-pin harness connector C202 (Black), located at base of left side of steering column. If headlights turn off, go to step 10 . If headlights do not turn off, go to next step.
  3. Disconnect LCM 24-pin harness connector C2 (Gray). If headlights turn off, go to step 6 . If headlights do not turn off, go to next step.
  4. Disconnect LCM 7-pin harness connector C1 (Black). If headlights turn off, go to step 8 . If headlights do not turn off, go to next step.
  5. If low beams will not turn off, repair short to battery voltage in circuit No. 12 (Tan wire) between LCM harness connector C1, instrument panel power distribution block and underhood junction block. If high beams will not turn off, repair short to battery voltage in circuit No. 11 (Light Green wire) between LCM harness connector C1, instrument panel junction block and underhood junction block. Perform «HEADLIGHT SYSTEM CHECK»(/buick/park-avenue/ii-1996-2002/remont/headlights/#headlights-automatic-twilight-sentinel__headlight-system-check) under TROUBLE SHOOTING.
  6. Check for short to ground in circuit No. 103 (White wire) between headlight switch and LCM harness connector C2. If circuit is okay, go to step 9 . If circuit is not okay, go to step 11 .
  7. Replace headlight switch. Perform «HEADLIGHT SYSTEM CHECK»(/buick/park-avenue/ii-1996-2002/remont/headlights/#headlights-automatic-twilight-sentinel__headlight-system-check) under TROUBLE SHOOTING.
  8. Replace LCM. See «LAMP CONTROL MODULE (LCM)»(/buick/park-avenue/ii-1996-2002/remont/headlights/#headlights-automatic-twilight-sentinel) under REMOVAL & INSTALLATION. Perform «HEADLIGHT SYSTEM CHECK»(/buick/park-avenue/ii-1996-2002/remont/headlights/#headlights-automatic-twilight-sentinel__headlight-system-check) under TROUBLE SHOOTING.
  9. Check for short to ground in circuit No. 307 (Yellow wire) between headlight dimmer switch and LCM harness connector C2. If circuit is okay, go to step 8 . If circuit is not okay, go to step 11 .
  10. Replace headlight dimmer switch. Perform «HEADLIGHT SYSTEM CHECK»(/buick/park-avenue/ii-1996-2002/remont/headlights/#headlights-automatic-twilight-sentinel__headlight-system-check) under TROUBLE SHOOTING.
  11. Repair short to ground in appropriate circuit. Perform «HEADLIGHT SYSTEM CHECK»(/buick/park-avenue/ii-1996-2002/remont/headlights/#headlights-automatic-twilight-sentinel__headlight-system-check) under TROUBLE SHOOTING.

Scheme 1

Scheme 1
Scheme 1

Scheme 2

Scheme 2
Scheme 2

LOW BEAM HEADLIGHTS INOPERATIVE

Note. Perform headlight system check before proceeding. See HEADLIGHT SYSTEM CHECK under TROUBLE SHOOTING.

  1. Disconnect LCM 7-pin harness connector C1 (Black). Using DVOM, measure voltage between LCM harness connector C1, terminal "G" (Red wire) and ground. If 10-15 volts exist, go to next step. If 10-15 volts do not exist, go to step 7 .
  2. Disconnect LCM 24-pin harness connector C2 (Gray). Using DVOM, measure voltage between LCM harness connector C1, terminal "G" (Red wire) and LCM harness connector C2, terminals B4 and B5 (Black/White wires). If 10-15 volts exists, go to next step. If 10-15 volts does not exist, go to step 8 .
  3. Using DVOM, measure voltage between LCM harness connector C1, terminals "G" (Red wire) and "E" (Black wire). If 10-15 volts exists, go to next step. If 10-15 volts does not exist, go to step 9 .
  4. Disconnect headlight switch harness connector, located at left side of instrument panel. Reconnect LCM harness connectors C1 and C2. Connect a fused jumper wire between headlight switch harness connector terminal "D" (White wire) and ground. If low beam headlights illuminate, go to step 10 . If low beam headlights do not illuminate, go to next step.
  5. Disconnect LCM 7-pin harness connector C1 (Black). Connect a fused jumper wire between LCM harness connector C1, terminals "G" (Red wire) and "F" (Tan wire). If low beam headlights illuminate, go to step 12 . If low beam headlights do not illuminate, go to next step.
  6. Repair open in circuit No. 12 (Tan wire) between LCM harness connector C1, instrument panel junction block and underhood junction block. Perform «HEADLIGHT SYSTEM CHECK»(/buick/park-avenue/ii-1996-2002/remont/headlights/#headlights-automatic-twilight-sentinel__headlight-system-check) under TROUBLE SHOOTING.
  7. Repair open or short to ground in circuit No. 1242 (Red wire) between LCM harness connector C1, underhood junction block and instrument panel junction block. Perform «HEADLIGHT SYSTEM CHECK»(/buick/park-avenue/ii-1996-2002/remont/headlights/#headlights-automatic-twilight-sentinel__headlight-system-check) under TROUBLE SHOOTING.
  8. Repair open in circuit No. 351 (Black/White wire) between LCM harness connector C2 and ground. Perform «HEADLIGHT SYSTEM CHECK»(/buick/park-avenue/ii-1996-2002/remont/headlights/#headlights-automatic-twilight-sentinel__headlight-system-check) under TROUBLE SHOOTING.
  9. Repair open in circuit No. 350 (Black wire) between LCM harness connector C1 and ground. Perform «HEADLIGHT SYSTEM CHECK»(/buick/park-avenue/ii-1996-2002/remont/headlights/#headlights-automatic-twilight-sentinel__headlight-system-check) under TROUBLE SHOOTING.
  10. Repair open in circuit No. 351 (Black/White wire) between headlight switch and ground. If circuit is okay, go to next step. If circuit is not okay, go to step 14 .
  11. Replace headlight switch. Perform «HEADLIGHT SYSTEM CHECK»(/buick/park-avenue/ii-1996-2002/remont/headlights/#headlights-automatic-twilight-sentinel__headlight-system-check) under TROUBLE SHOOTING.
  12. Check for open in circuit No. 103 (White wire) between headlight switch and LCM harness connector C2. If circuit is okay, go to next step. If circuit is not okay, go to step 14 .
  13. Replace LCM. See «LAMP CONTROL MODULE (LCM)»(/buick/park-avenue/ii-1996-2002/remont/headlights/#headlights-automatic-twilight-sentinel) under REMOVAL & INSTALLATION. Perform «HEADLIGHT SYSTEM CHECK»(/buick/park-avenue/ii-1996-2002/remont/headlights/#headlights-automatic-twilight-sentinel__headlight-system-check) under TROUBLE SHOOTING.
  14. Repair open in appropriate circuit. Perform «HEADLIGHT SYSTEM CHECK»(/buick/park-avenue/ii-1996-2002/remont/headlights/#headlights-automatic-twilight-sentinel__headlight-system-check) under TROUBLE SHOOTING.

HIGH BEAM HEADLIGHTS INOPERATIVE

Note. Perform headlight system check before proceeding. See HEADLIGHT SYSTEM CHECK under TROUBLE SHOOTING.

  1. Disconnect headlight dimmer switch 48-pin harness connector C202, located at base of steering column. Turn headlights on. Connect a fused jumper wire between harness connector C202, terminal A8 (Purple wire) and ground. If headlights switch from low beams to high beams, go to step 4 . If headlights do not switch from low beams to high beams, go to next step.
  2. Disconnect LCM 7-pin harness connector C1 (Black). Connect a fused jumper wire between LCM harness connector C1, terminals "D" (Dark Blue wire) and "E" (Black wire). Connect an additional fused jumper wire between LCM harness connector C1, terminals "G" (Red wire) and "B" (Light Green wire). If high beam headlights illuminate, go to step 6 . If high beam headlights do not illuminate, go to next step.
  3. Repair open in circuit No. 11 (Light Green wire) between LCM harness connector C1, instrument panel junction block and underhood junction block. Perform «HEADLIGHT SYSTEM CHECK»(/buick/park-avenue/ii-1996-2002/remont/headlights/#headlights-automatic-twilight-sentinel__headlight-system-check) under TROUBLE SHOOTING.
  4. Check for open in circuit No. 351 (Black/White wire) between headlight dimmer switch and ground. If circuit is okay, go to next step. If circuit is not okay, go to step 8 .
  5. Replace headlight dimmer switch. Perform «HEADLIGHT SYSTEM CHECK»(/buick/park-avenue/ii-1996-2002/remont/headlights/#headlights-automatic-twilight-sentinel__headlight-system-check) under TROUBLE SHOOTING.
  6. Check for open in circuit No. 524 (Purple wire) between LCM harness connector C2 and headlight dimmer switch. If circuit is okay, go to next step. If circuit is not okay, go to step 8 .
  7. Replace LCM. See «LAMP CONTROL MODULE (LCM)»(/buick/park-avenue/ii-1996-2002/remont/headlights/#headlights-automatic-twilight-sentinel) under REMOVAL & INSTALLATION. Perform «HEADLIGHT SYSTEM CHECK»(/buick/park-avenue/ii-1996-2002/remont/headlights/#headlights-automatic-twilight-sentinel__headlight-system-check) under TROUBLE SHOOTING.
  8. Repair open in appropriate circuit. Perform «HEADLIGHT SYSTEM CHECK»(/buick/park-avenue/ii-1996-2002/remont/headlights/#headlights-automatic-twilight-sentinel__headlight-system-check) under TROUBLE SHOOTING.

DAYTIME RUNNING LIGHTS (DRL) INOPERATIVE

Note. Perform headlight system check before proceeding. See HEADLIGHT SYSTEM CHECK under TROUBLE SHOOTING.

  1. Disconnect LCM 24-pin harness connector C2 (Gray). Cover ambient light sensor. Using DVOM, measure resistance between LCM harness connector C2, terminal A5 (White wire) and ground. If resistance is greater than 31 k/ohms, go to next step. If resistance is 31 k/ohms or less, go to step 10 .
  2. Expose ambient light sensor to sunlight or bright incandescent light. Using DVOM, measure resistance between LCM harness connector C2, terminal A5 (White wire) and ground. If resistance is less than 23 k/ohms, go to next step. If resistance is 23 k/ohms or greater, go to step 10 .
  3. Turn ignition on. Using DVOM, measure voltage between LCM harness connector C2, terminal A7 (Pink wire) and ground. If 10-15 volts exists, go to next step. If 10-15 volts does not exist, go to step 13 .
  4. Place gearshift lever in Park. Using DVOM, measure voltage between LCM harness connector C2, terminal A8 (Light Green wire) and ground. If 10-15 volts exists, go to step 14 . If 10-15 volts does not exist, go to next step.
  5. Disconnect LCM 7-pin harness connector C1 (Black). Connect a fused jumper wire between LCM harness connector C1, terminals "G" (Red wire) and "D" (Dark Blue wire). If high beam headlights illuminate at reduced intensity, go to step 9 . If high beam headlights do not illuminate at reduced intensity, go to next step.
  6. Check for open or short to ground in circuit No. 593 (Dark Blue wire) between LCM harness connector C1 and left-side high beam headlight. If circuit is okay, go to next step. If circuit is not okay, go to step 17 .
  7. Check for open in circuit No. 711 (Dark Green/White wire) between underhood junction block harness connector C1 and left-side high beam headlight. If circuit is okay, go to next step. If circuit is not okay, go to step 17 .
  8. Check for open in circuit No. 311 (Light Green wire) between underhood junction block harness connector C1 and right-side high beam headlight. If circuit is okay, go to step 16 . If circuit is not okay, go to step 17 .
  9. Replace LCM. See «LAMP CONTROL MODULE (LCM)»(/buick/park-avenue/ii-1996-2002/remont/headlights/#headlights-automatic-twilight-sentinel) under REMOVAL & INSTALLATION. Perform «HEADLIGHT SYSTEM CHECK»(/buick/park-avenue/ii-1996-2002/remont/headlights/#headlights-automatic-twilight-sentinel__headlight-system-check) under TROUBLE SHOOTING.
  10. Check for short to ground or open in circuit No. 278 (White wire) between LCM harness connector C2 and ambient light sensor. If circuit is okay, go to next step. If circuit is not okay, go to step 17 .
  11. Check for open in circuit No. 351 (Black/White wire) between ambient light sensor and ground. If circuit is okay, go to next step. If circuit is not okay, go to step 17 .
  12. Replace ambient light sensor. See «AMBIENT LIGHT SENSOR»(/buick/park-avenue/ii-1996-2002/remont/headlights/#headlights-automatic-twilight-sentinel) under REMOVAL & INSTALLATION. Perform «HEADLIGHT SYSTEM CHECK»(/buick/park-avenue/ii-1996-2002/remont/headlights/#headlights-automatic-twilight-sentinel__headlight-system-check) under TROUBLE SHOOTING.
  13. Repair open or short to ground in circuit No. 39 (Pink wire) between LCM harness connector C2, instrument panel junction block and underhood junction block. Perform «HEADLIGHT SYSTEM CHECK»(/buick/park-avenue/ii-1996-2002/remont/headlights/#headlights-automatic-twilight-sentinel__headlight-system-check) under TROUBLE SHOOTING.
  14. Check for short to battery voltage in circuit No. 275 (Light Green wire) between LCM harness connector C2 and Body Control Module (BCM). If circuit is okay, see appropriate BODY CONTROL MODULES article. If circuit is not okay, go to step 17 .
  15. Replace LCM. See «LAMP CONTROL MODULE (LCM)»(/buick/park-avenue/ii-1996-2002/remont/headlights/#headlights-automatic-twilight-sentinel) under REMOVAL & INSTALLATION. Perform «HEADLIGHT SYSTEM CHECK»(/buick/park-avenue/ii-1996-2002/remont/headlights/#headlights-automatic-twilight-sentinel__headlight-system-check) under TROUBLE SHOOTING.
  16. Repair open in circuit No. 250 (Black wire) between right-side high beam headlight and ground. Perform «HEADLIGHT SYSTEM CHECK»(/buick/park-avenue/ii-1996-2002/remont/headlights/#headlights-automatic-twilight-sentinel__headlight-system-check) under TROUBLE SHOOTING.
  17. Repair open or short to ground in appropriate circuit. Perform «HEADLIGHT SYSTEM CHECK»(/buick/park-avenue/ii-1996-2002/remont/headlights/#headlights-automatic-twilight-sentinel__headlight-system-check) under TROUBLE SHOOTING.

TWILIGHT SENTINEL INOPERATIVE

Note. Perform headlight system check before proceeding. See HEADLIGHT SYSTEM CHECK under TROUBLE SHOOTING.

  1. Disconnect LCM 24-pin harness connector C2 (Black). Turn ignition on. Using DVOM, measure voltage between LCM harness connector C2, terminal A7 (Pink wire) and ground. If 10-15 volts exists, go to next step. If 10-15 volts does not exist, go to step 6 .
  2. While varying twilight delay control from MIN to MAX, using DVOM, measure resistance between LCM harness connector C2, terminal A6 (Purple wire) and ground. If resistance is 3.5-200 k/ohms, go to next step. If resistance is not as specified, go to step 7 .
  3. Cover ambient light sensor. Using DVOM, measure resistance between LCM harness connector C2, terminal A5 (White wire) and ground. If resistance is greater than 31 k/ohms, go to next step. If resistance is 31 k/ohms or less, go to step 10 .
  4. Expose ambient light sensor to sunlight or bright incandescent light. Using DVOM, measure resistance between LCM harness connector C2, terminal A5 (White wire) and ground. If resistance is less than 23 k/ohms, go to next step. If resistance is 23 k/ohms or greater, go to step 10 .
  5. Replace LCM. See «LAMP CONTROL MODULE (LCM)»(/buick/park-avenue/ii-1996-2002/remont/headlights/#headlights-automatic-twilight-sentinel) under REMOVAL & INSTALLATION. Perform «HEADLIGHT SYSTEM CHECK»(/buick/park-avenue/ii-1996-2002/remont/headlights/#headlights-automatic-twilight-sentinel__headlight-system-check) under TROUBLE SHOOTING.
  6. Repair open or short to ground in circuit No. 39 (Pink wire) between LCM harness connector C2, instrument panel junction block and underhood junction block. Perform «HEADLIGHT SYSTEM CHECK»(/buick/park-avenue/ii-1996-2002/remont/headlights/#headlights-automatic-twilight-sentinel__headlight-system-check) under TROUBLE SHOOTING.
  7. Check for open in circuit No. 1783 (Purple wire) between LCM harness connector C2 and headlight switch. If circuit is okay, go to next step. If circuit is not okay, go to step 13 .
  8. Check for open in circuit No. 351 (Black/White wire) between headlight switch and ground. If circuit is okay, go to next step. If circuit is not okay, go to step 13 .
  9. Replace headlight switch. Perform «HEADLIGHT SYSTEM CHECK»(/buick/park-avenue/ii-1996-2002/remont/headlights/#headlights-automatic-twilight-sentinel__headlight-system-check) under TROUBLE SHOOTING.
  10. Check for open or short to ground in circuit No. 278 (White wire) between LCM harness connector C2 and ambient light sensor. If circuit is okay, go to next step. If circuit is not okay, go to step 13 .
  11. Check for open in circuit No. 351 (Black/White wire) between ambient light sensor and ground. If circuit is okay, go to next step. If circuit is not okay, go to step 13 .
  12. Replace ambient light sensor. See «AMBIENT LIGHT SENSOR»(/buick/park-avenue/ii-1996-2002/remont/headlights/#headlights-automatic-twilight-sentinel) under REMOVAL & INSTALLATION. Perform «HEADLIGHT SYSTEM CHECK»(/buick/park-avenue/ii-1996-2002/remont/headlights/#headlights-automatic-twilight-sentinel__headlight-system-check) under TROUBLE SHOOTING.
  13. Repair open or short to ground in appropriate circuit. Perform «HEADLIGHT SYSTEM CHECK»(/buick/park-avenue/ii-1996-2002/remont/headlights/#headlights-automatic-twilight-sentinel__headlight-system-check) under TROUBLE SHOOTING.

REMOVAL & INSTALLATION

WARNINGBefore servicing instrument panel components on vehicles with Supplemental Inflatable Restraint (SIR) system, disable SIR system. See DISABLING & ACTIVATING AIR BAG SYSTEM in appropriate AIR BAG RESTRAINT SYSTEMS article.
CAUTIONWhen battery is disconnected, vehicle computer and memory systems may lose memory data. Driveability problems may exist until computer systems have completed a relearn cycle. See COMPUTER RELEARN PROCEDURES article in GENERAL INFORMATION before disconnecting battery.

Ambient light sensor is mounted in defroster grille. Unsnap defroster grille. Twist photocell counterclockwise to disengage photocell and socket. Unplug harness connector. To install, reverse removal procedure.

Remove driver's side knee bolster. Remove 3 LCM bolts. (Scheme 3) Disconnect wiring. Remove LCM. To install, reverse removal procedure.

Scheme 3

Scheme 3: Removal & Installation
Scheme 3: Removal & Installation

WIRING DIAGRAMS

Note. For twilight sentinel system wiring diagrams, see HEADLIGHT SYSTEMS & DAYTIME RUNNING LIGHTS article.

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