Headlights - Automatic Twilight Sentinel Buick Riviera VIII

Description

Headlights on vehicles equipped with twilight sentinel system are controlled by a Lamp Control Module (LCM), Daytime Running Lights (DRL) Module, or Central Control Module (CCM). An ambient light sensor (photocell), mounted to top of instrument panel or under left defroster grille, is used to sense light levels. When headlights are turned on, or photocell senses darkness, input to control module is grounded, and module applies power to exterior lighting circuits.

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 30-second delay before switching lights on or off, thus preventing system from operating under sudden ambient lighting changes, such as passing through tunnels or exposure to bright lights at night.

AIR BAG PRECAUTIONS

Observe following precautions when working on vehicles equipped with Supplemental Inflatable Restraint (SIR) air bag systems

1. Disable SIR system before performing any instrument panel testing, diagnosis or repair. Turn wheels to straight-ahead position. Turn ignition switch to LOCK position. Remove AIR BAG or SIR fuse. Disconnect Yellow 2-pin connector at base of steering column.
2. To enable SIR system to power down, wait 20 minutes before making any repairs. System back-up power supply retains enough voltage to deploy air bag for a short time after battery is disconnected.
3. To avoid accidental air bag deployment, avoid Yellow SIR wiring harnesses when trouble shooting, repairing, or replacing instrument panel components. All SIR wiring harnesses are Yellow.
4. To activate system, reverse procedure. Turn ignition switch to RUN position. Verify air bag warning light flashes 7-9 times and then goes out.

HANDLING PRECAUTIONS

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 put component on metal work bench, metal objects, or electrically operated components, such as radio, TV, or oscilloscope.

PRELIMINARY TROUBLE SHOOTING

1. Check headlight system operation with manual switch. If all headlights operate okay manually, but twilight sentinel does not operate properly, proceed to test with appropriate symptom. If headlights do not operate properly with manual switch, go to next step.
2. If headlight do not operate at all, inspect all fuses and circuit breakers. If fuses repeatedly blow, check problem circuit for short to ground. If any headlight is dim, inspect ground connections. If one headlight is inoperative, inspect suspect bulb. After making any repair recheck headlight system function.

LIGHTS DO NOT AUTOMATICALLY TURN ON IN DARKNESS

Check for loose connection at headlight switch or module connector. Check for open wiring between fusible link and headlight switch, inoperative headlight switch or circuit breaker. Check for open in ground path through on-off switch of time-delay control of sentinel switch. Check for inoperative photocell or module.

LIGHTS DO NOT TURN OFF IN DAYLIGHT

Check for inoperative or obstructed photocell. Check for poor contact between photocell and socket, socket disengaged from mounting hole, or faulty module.

LIGHTS DO NOT TURN OFF AFTER IGNITION IS OFF

Check for blown fuse, inoperative time delay control, open wiring, inoperative module or malfunctioning photocell.

LIGHTS DO NOT STAY ON PROPER TIME SPAN AFTER IGNITION IS OFF

Check for inoperative time delay control or high resistance at module connector. Check for short in wiring or inoperative module.

WARNING CHIME DOES NOT OPERATE

Check for open wire in chime circuit, inoperative door jam switch or poor connection at headlight switch. Check for inoperative module, blown fuse or time delay control malfunction.

TESTING

Note. Unless otherwise specified, make all measurements with a digital volt-ohmmeter with an input impedance of 10 megohms.

SYSTEM CHECK (WITHOUT DRL)

1. Turn low beam headlights on. If low beams do not turn on, go to appropriate «TEST "A", HEADLIGHTS INOPERATIVE»(/buick/riviera/viii-1994-1999/remont/headlights/#headlights-automatic-twilight-sentinel) . Turn ignition, twilight sentinel, and headlights off. If exterior lights are off, go to next step. If exterior lights remain on, go to «TEST "B", LIGHTS DO NOT TURN OFF»(/buick/riviera/viii-1994-1999/remont/headlights/#headlights-automatic-twilight-sentinel__test-b-lights-do-not-turn) .
2. Turn ignition on. Turn headlights off. Turn twilight sentinel on. Cover photocell on top of instrument cluster with dark paper. Exterior lights should turn on after about 30 seconds. If lights do not turn on, go to «TEST "C", TWILIGHT SENTINEL/DRL INPUT TEST»(/buick/riviera/viii-1994-1999/remont/headlights/#headlights-automatic-twilight-sentinel__test-c-twilight-sentineldrl-input-test) .
3. Uncover photocell. Expose photocell to sunlight or bright incandescent light. Exterior lights should turn off within 30 seconds. If lights do not turn off, go to «TEST "C", TWILIGHT SENTINEL/DRL INPUT TEST»(/buick/riviera/viii-1994-1999/remont/headlights/#headlights-automatic-twilight-sentinel__test-c-twilight-sentineldrl-input-test) .
4. Cover photocell. Wait for lights to turn on. Turn ignition off. Set twilight sentinel control to MAX delay position. Lights should turn off after about 3 minutes. If lights turn off, system is working properly. If lights do not turn off, go to «TEST "C", TWILIGHT SENTINEL/DRL INPUT TEST»(/buick/riviera/viii-1994-1999/remont/headlights/#headlights-automatic-twilight-sentinel__test-c-twilight-sentineldrl-input-test) .

SYSTEM CHECK (WITH DRL)

1. Turn low beam headlights on. If low beams do not turn on, go to appropriate «TEST "A", HEADLIGHTS INOPERATIVE»(/buick/riviera/viii-1994-1999/remont/headlights/#headlights-automatic-twilight-sentinel) . Turn ignition, twilight sentinel, and headlights off. If exterior lights are off, go to next step. If exterior lights remain on, go to «TEST "B", LIGHTS DO NOT TURN OFF»(/buick/riviera/viii-1994-1999/remont/headlights/#headlights-automatic-twilight-sentinel__test-b-lights-do-not-turn) .
2. Turn headlights off. Set gear selector to Park. Turn ignition on. If headlights and exterior lights are off, go to next step. If headlights and exterior lights are on, go to «TEST "C", TWILIGHT SENTINEL/DRL INPUT TEST»(/buick/riviera/viii-1994-1999/remont/headlights/#headlights-automatic-twilight-sentinel__test-c-twilight-sentineldrl-input-test) .
3. Apply parking brake. Expose photocell to sunlight or bright incandescent light. Set gear selector to "D" position. If headlights are on and exterior lights are off, go to next step. If headlights are off and/or exterior lights are on, go to «TEST "C", TWILIGHT SENTINEL/DRL INPUT TEST»(/buick/riviera/viii-1994-1999/remont/headlights/#headlights-automatic-twilight-sentinel__test-c-twilight-sentineldrl-input-test) .
4. Set gear selector to Park. Turn ignition on. Turn headlights off. Turn twilight sentinel on. Cover photocell with dark paper. If exterior lights turn on after about 30 seconds, go to next step. If exterior lights do not turn on after about 30 seconds, go to «TEST "C", TWILIGHT SENTINEL/DRL INPUT TEST»(/buick/riviera/viii-1994-1999/remont/headlights/#headlights-automatic-twilight-sentinel__test-c-twilight-sentineldrl-input-test) .
5. Set twilight sentinel control to MAX delay position. Turn ignition off. If exterior lights turn off after about 3 minutes, system is working properly. If operation is not as described, go to «TEST "C", TWILIGHT SENTINEL/DRL INPUT TEST»(/buick/riviera/viii-1994-1999/remont/headlights/#headlights-automatic-twilight-sentinel__test-c-twilight-sentineldrl-input-test) .

Aurora

1. Turn headlights off. Disconnect lamp control module 6-pin connector located at left side of instrument panel. (Scheme 1) Measure voltage between lamp control module 6-pin connector terminal "E" (Orange wire) and ground. If battery voltage exists, go to next step. If battery voltage does not exist, repair open or short to ground in Orange wire.
2. Disconnect lamp control module 16-pin connector. Turn headlights on. Measure voltage between lamp control module 16-pin connector terminal B1 (White wire) and battery voltage. If battery voltage exists, go to next step. If battery voltage does not exist, repair open in White wire. If wire is okay, replace headlight switch.
3. Connect fused jumper between lamp control module 6-pin connector terminal "D" (Light Blue wire) and battery voltage. If low beam headlights are on, replace lamp control module. If low beam headlights are off, repair open in Light Blue wire between lamp control module and headlight dimmer switch, or repair open in Tan wire between headlight dimmer switch and headlight assembly. If wires are okay, replace headlight dimmer switch.

Riviera

1. Turn headlights off. Disconnect lamp control module 6-pin connector located at left side of instrument panel. (Scheme 1) Measure voltage between lamp control module 6-pin connector, terminal "E" (Orange wire) and ground. If battery voltage exists, go to next step. If battery voltage does not exist, repair open or short to ground in Orange wire.
2. Connect lamp control module 6-pin connector. Disconnect headlight switch connector. Connect fused jumper between headlight switch connector terminal No. 6 (White wire) and ground. If low beam headlights are off, go to next step. If low beam headlights are on, repair open in Black/White wire between lamp control module and headlight switch. If wire is okay, replace headlight switch.
3. Connect headlight switch connector. Disconnect headlight dimmer switch connector. Turn headlights on. Measure voltage between headlight dimmer switch connector terminal E13 (Light Blue wire) and ground. If battery voltage exists, repair open in Tan wire between headlight dimmer switch and headlight assembly. If wire is okay, replace headlight dimmer switch.
4. If battery voltage does not exist, repair open in Light Blue wire between lamp control module and headlight dimmer switch, or repair open in White wire between headlight switch and lamp control module. If wires are okay, replace lamp control module.

TEST "B", LIGHTS DO NOT TURN OFF

1. Disconnect headlight switch connector. If lights remain on, go to next step. If lights are off, repair short to ground in Gray/Black wire or White wire. If wire(s) are okay, replace headlight switch.
2. Disconnect lamp control module 6-pin connector located at left side of instrument panel. (Scheme 1) If lights turn off, replace lamp control module. If lights remain on, disconnect headlight dimmer switch connector. If lights remain on, repair short to voltage in Tan wire (low beam) or Light Green wire (high beam) between headlight assembly and headlight dimmer switch. If lights turn off, repair short to voltage in Light Blue wire. If wire is okay, replace headlight dimmer switch.

TEST "C", TWILIGHT SENTINEL/DRL INPUT TEST

1. Disconnect lamp control module 6-pin connector located at left side of instrument panel. (Scheme 1) Turn ignition on. Measure voltage between lamp control module 6-pin connector terminal "C" (Pink wire) and ground. If battery voltage exists, go to next step. If battery voltage does not exist, repair open or short to ground in Pink wire between ignition switch and lamp control module.
2. Turn ignition off. Disconnect lamp control module 16-pin connector. Turn twilight sentinel on. Measure resistance between lamp control module 16-pin connector terminals B6 (Black/White wire) and B8 (Yellow/Black wire). If resistance is less than 5 ohms, go to next step. If resistance is more than 5 ohms, repair open in Yellow/Black wire between lamp control module and twilight sentinel switch, or repair open in Black/White wire between ground and lamp control module. If wires are okay, replace twilight sentinel switch.
3. Measure resistance between lamp control module 16-pin connector terminals A1 (Purple wire) and B6 (Black/White wire) while varying twilight sentinel switch from MIN to MAX delay position. If resistance varies between 3.5 k/ohms and 200 k/ohms or more, go to next step. If resistance does not vary between 3.5 k/ohms and 200 k/ohms or more, repair open or short to ground in Purple wire between lamp control module and twilight sentinel switch. If wire is okay, replace twilight sentinel switch.
4. Measure resistance between lamp control module 16-pin connector terminals A2 (White/Black wire) and B6 (Black/White wire). Cover photocell and record resistance. Uncover photocell and record resistance with photocell exposed to bright incandescent light or sunlight.
5. If resistance is more than 31 k/ohms with photocell covered and less than 23 k/ohms with photocell exposed to light, and vehicle is not equipped with daytime running lights, replace lamp control module. If resistance is more than 31 k/ohms with photocell covered and less than 23 k/ohms with photocell exposed to light, repair open or short to ground in White/Black, White or Black wires between lamp control module and photocell, or repair open in Black/White ground wire at photocell. If wires are okay, replace photocell.
6. If vehicle is equipped with daytime running lights, apply parking brake. Measure voltage between lamp control module 16-pin connector terminal A7 (Light Green wire) and ground. Set gear selector to Park. Record voltage. Set gear selector to Drive. Record voltage. Battery voltage should exist with gear selector in Park. No voltage should exist with gear selector in Drive.
7. If voltages are as specified, go to next step. If voltages are not as specified, repair open or short to ground in Pink wire between park/neutral position switch and instrument panel fuse block, or in Light Green wire between lamp control module and park/neutral position switch. If wires are okay, replace park/neutral position switch.
8. Connect fused jumper between lamp control module 6-pin connector terminals "C" (Pink wire) and "G" (Gray wire). If low beam headlights turn on at reduced intensity, replace lamp control module. If low beam headlights do not turn on at reduced intensity, repair open in Gray wire or Tan wire at daytime running lights resistor located at left front corner of engine compartment. If wires are okay, replace resistor.

Scheme 1

REMOVAL & INSTALLATION

TWILIGHT SENTINEL CONTROL MODULE

Note. Twilight sentinel may be also known as daytime running light module, lamp control module or central control module.

Disconnect negative battery cable. Remove left sound insulator. Press mounting bracket tab toward front of vehicle until mounting rails disengage. Remove connector bolt. Remove module. To install, reverse removal procedure.

Depending on model, photocell is either mounted under left defroster grille or secured to top of instrument panel. Unsnap defroster grille. Twist photocell counterclockwise to disengage photocell and socket. Unplug connector. To install, reverse removal procedure.

Aurora (With DRL & Twilight Sentinel). Scheme 2

Aurora (Without DRL & Twilight Sentinel). Scheme 3

Riviera (With DRL & Twilight Sentinel). Scheme 4

Riviera (Without DRL & Twilight Sentinel). Scheme 5

See also:
• COMPUTER RELEARN PROCEDURES
• AIR BAG PRECAUTIONS
• TEST "A", HEADLIGHTS INOPERATIVE
• TEST "B", LIGHTS DO NOT TURN OFF
• TEST "C", TWILIGHT SENTINEL/DRL INPUT TEST