USA/Canada/Saudi

CIRCUIT OPERATION
The Twilight Sentinel/DRL Module is designed to automatically turn "ON" the Headlights and Exterior Lights when it is dark outside. the module will also keep the lights "ON" for a selected amount of time after the ignition has been turned "OFF" (delayed exit).


Headlight Operation
Circuit Breaker 3 applies voltage to the Headlight Relay's coil and contacts at all times. the relay is energized when the coil is grounded through CKT 1346 by the Headlight Switch, the Twilight Sentinel/DRL Module or the Theft Deterrent Relay. When energized, the relay through its contacts applies voltage from Circuit Breaker 3 to the Headlight Dimmer Switch. the Headlight Dimmer Switch directs the voltage to either the low beam headlights or high beam headlights. the headlights are grounded through CKT 152 to either G100 or G101.


Flash to Pass
The flash to pass feature allows the high beams to be turned "ON" momentarily by pulling the multi-function lever. When the lever is pulled, the Headlight Dimmer Switch contacts move to the FLASH position. This allows voltage from Circuit Breaker 3 to be applied directly to the high beam headlights through CKT 11. the lights will stay "ON" for as long as the lever is pulled into FLASH position. the high beam indicator will also be illuminated when the ignition is in run, since voltage is also applied to the Instrument Panel Cluster (terminal C1/D15) through CKT 11.

Twilight Sentinel
The Twilight Sentinel/DRL Module is mounted to the back of the Headlight Switch. All input and output signals applied to the module must pass through the Headlight Switch.

The Twilight Sentinel systems functions are controlled by the enable switch, twilight delay rheostat and the Twilight Photocell. When the enable switch is in the "OFF" position, the Twilight Sentinel/DRL Module's twilight enable input terminal (5B) is grounded. This signals the module not to operate the Twilight and delayed exit functions. When the module's twilight enable input terminal (5B) is not grounded the module will enable the Twilight and delayed exit functions.

The twilight delay rheostat is connected to the Twilight Sentinel/DRL Module's twilight delay input terminal (7B). As the delay rheostat position changes the resistance across the rheostat changes. This signals the module as to how long it should keep the lights "ON" after the ignition has been turned "OFF". When the rheostat's resistance is approximately 4000 ohms the delay exit time-out is about 3 minutes. When the rheostat's resistance falls to 1 ohm the delay is no more than 1 second.

The Twilight Photocell is a variable resistor whose resistance changes as the level of ambient light around it changes. the Twilight Sentinel/DRL Module monitors the resistance of the Twilight Photocell at terminal 8B. the module interprets a photocell resistance of 90k Ohms or higher as nighttime and will turn "ON" the headlights and exterior lights. A photocell resistance of less than 72k Ohms is considered daylight signalling the module to turn "OFF" the lights. If the Twilight Sentinel/DRL Module detects that the photocell circuit is open, the module will default to the nighttime mode.

Twilight Sentinel Output
The Twilight Sentinel/DRL Module will turn "ON" the headlights when it sees that the ignition is in run, the photocell indicates darkness and the twilight enable switch is in the "ON" position. When these conditions occur the module grounds its headlight control terminal (3B) and park light control terminal (1B). The headlight control when closed grounds the Headlight Relay through CKT 1346 and the Headlight Switch. This causes the relay to energize and turn "ON" the headlights. the module's park light control when closed, grounds the Park Lights Relay through CKT 1345 and the Headlight Switch. This causes the Park Lights Relay to energize and turn "ON" the exterior lights.

Delayed Exit Mode
When the ignition is turned "OFF" and the headlights have been turned "ON", the Twilight Sentinel/DRL Module enters the delayed exit mode. the delayed exit mode keeps the headlights and the exterior lights "ON" for up to 3 minutes depending on the resistance of the delay rheostat. the delayed exit mode is entered when voltage is no longer applied at the Twilight Sentinel/DRL Module's ignition input terminal (5 A).

Daytime Running Lights: DRL (Canadian Vehicles)
On vehicles equipped with the daytime running lights feature (T61), the Twilight Sentinel/DRL Module has an additional function. This added function is to turn "ON" the low beam headlights at a reduced intensity in daylight conditions. the Twilight Sentinel/DRL Module will enter the DRL mode when the Twilight Photocell indicates daylight, the ignition is in run and the gear selector is not in park. If the car is placed in park after the daytime running lights are "ON", the module will turn "OFF" the lights.

The Twilight Sentinel/DRL Module determines if its daylight by monitoring the Twilight Photocell and the module knows when the ignition is in run when voltage is applied to its ignition on input terminal (5A). The transaxle position is monitored at the modules park input terminal (2B), voltage is applied to this terminal from Fuse A3 whenever the Transaxle Position Switch is in the park position.

When the Twilight Sentinel/DRL Module enters the DRL mode, the module's daytime running lights control terminal (4B) closes grounding the DRL Headlight Relay's coil through CKT 592. the DRL Headlight Relay energizes and applies voltage from Circuit Breaker 3 to the Daytime Running Lights Resistor and the low beam headlights. the Daytime Running Lights Resistor reduces the voltage applied to the low beam headlights. the headlights will light but will be lit at a reduced intensity.

Fog Lights
Fuse C11 applies voltage to the Fog Light Relay coil and contacts. When the Fog Lights Switch is turned "ON", the Fog Light Relay coil is grounded energizing the relay. With the relay energized, voltage from Fuse C11 is applied to the Fog Lights through the relays closed contacts and CKT 34. the Fog Lights are grounded through CKT 150 at ground G101.

The Fog Lights will automatically be turned "OFF" whenever the hi beam headlights are turned "ON" or the flash to pass feature is operated. When either one of these conditions occurs, voltage applied to the hi beam headlights is simultaneously applied to the Fog Light Inhibit Relay's coil. the Fog Light Inhibit Relay energizes and opens its contacts. the inhibit relays normally closed contacts allows voltage to be applied to the Fog Lights Relay's coil. When the Fog Light Inhibit Relay is energized its contacts open causing the Fog Light Relay's coil circuit to be interrupted. the Fog Light Relay now de-energizes and turns "OFF" the Fog Lights.