Allante V8-273 4.5L (1991)
Fog/Driving Lamp: Description and Operation
The status of the Switches in the Left Switch Pod is transmitted to the Body Computer Module (BCM) through the Data Line. The BCM controls the
lights by sending commands through the Data Lines to the Output Switch Modules. The Output Switch Modules switch the lights on and off.
The Headlight Switch is a momentary switch which is latched by LSP hardware control.
When the Headlight Switch is first activated, the Lo Beam function and Park Light function are enabled. The Headlights are de-activated by depressing
the Headlight, Park Lights or LIGHTS OFF Switch.
Pulling the Multi-Function Lever with the Ignition Switch ON or OFF and the Headlight system enabled, changes the state of the headlight system
between Hi Beam function and Lo Beam function.
With the Ignition Switch in RUN and the Headlight System not enabled, pulling the Multi-Function Lever enables the Hi Beam function as long as the
lever is held back.
Pressing the Park Lights Switch with the Headlights on turns off the Headlights and the Headlights 'LED but leaves the Park Lights on and turns on the
Park Lights' LED. Pushing the Park Lights Switch at this time would turn the Park Lights off, as would pushing the LIGHTS OFF Switch. Pushing the
Headlight Switch would turn the Headlights and Headlights' LED back on while turning the Park Lights' LED off.
When the Front Fog Switch is first activated with the Ignition Switch in RUN, Fog Light function and Park Light function are enabled, unless the system
is presently in the Hi Beam mode. Activating the Front Fog Switch again disables the Fog Light and Park Light functions only.
Pressing the LIGHTS OFF Switch turns off the Headlights, Park Lights, and Fog Lights if they are already on through manual driver control.
With Fog Lights on, depressing the Park Lights button will deactivate the Fog Lights and leave only the Park Lights on. The Fog Light function will be
disabled whenever the Ignition is turned OFF or while the Hi Beam function is enabled.
The LED`s are meant to indicate that the driver has selected the indicated function. If the lights are turned on or off by the automatic functions, the LED's
are not activated.
As an example, if Twilight Sentinel turns on the Headlights and Park Lights, the Headlights' and Park Lights' LED`s would not turn on, as this is an
automatic function. If the driver turns on the Headlight Switch the LED for the Headlights would come on. This would happen whether or not the
Twilight Sentinel had already turned on the lights, since it is a manual override and would require the driver to turn the lights back off. When the driver
turns the lights off by means of the Headlight Switch, the LED goes off. If Twilight Sentinel attempts to turn off the lights while the driver control
indicates that they should be on, the lights and LED would stay on.
The light (filament) substitution feature allows operation of the vehicle's lighting system in a manner that is very similar to normal operation, even with a
failed filament. A Fog Light will be substituted for a Lo Beam filament, and a Lo Beam filament will be substituted for a Hi Beam filament.
The Redundant Relay output of the BCM will be enabled whenever a failure of the distributed lighting system data line or BCM is detected when the
Headlights have been selected. Otherwise, the output is disabled. When the redundant lighting is enabled, the output will supply ground to the relay and
engage the relay. The Ignition Switch also supplies ground to the LH Headlight Redundant Relay and engages it whenever the Ignition Switch is in
START. Refer to the operation of the LH Tail Light Redundant Relay.
