Chevrolet Equinox Service Manual: Interior Lighting Systems Description and Operation Lighting Interior Lighting

Interior Lamps

The interior lamps consist of 2 groups, those which can dimfrom the instrument panel cluster lamps dimmer switch and thosethat can not dim.

Courtesy/Illuminated Entry Lamps

The following lamps may be manually turned ON by placing theinterior lamp switch in the ON position, or by opening a door whilethe switch is in the AUTO position.

The dome lampThe liftgate lampsCourtesy lamps

The courtesy lamp supply voltage circuit of the body controlmodule (BCM) supplies battery positive voltage to the dome lamp,the liftgate lamps and courtesy lamps. When any door is opened, thedoor jamb switch contacts close providing a door open input to theBCM. The BCM then provides a B+ to the interior lamps with theswitch in the AUTO position. The interior lamps receive a groundwhen the switch is in the ON position.

Note:If the liftgate is opened after all the modules go to sleep,the dome light will not come on. The liftgate ajar switch input tothe BCM will not wake up the BCM once it has gone to sleep, so thedome light will not come on. Once the BCM gets an input to wake itup, from remote keyless entry or a door handle, the dome light willturn on when the liftgate is opened.

If the driver inadvertently leaves any interior lamp ON, theBCM will turn it OFF after a 20-min time-out.

The courtesy lamps will turn OFF immediately if the ignitionswitch is turned to the ON position or approximately20-s after all doors are closed.

Keyless Entry Interior Illumination

When the BCM receives a door unlock command from the remotekeyless entry transmitter, the BCM will flash the park lampsseveral times, illuminate the courtesy and park lamps, andilluminate the low beam headlamps at low intensity. The lamps willremain on until the ignition key is turned from the OFF position, akeyless entry transmitter door lock command is received, or afteran approximate 20-s delay.

Interior Lamps Dimming

This group includes lamps which may dim. This group may use acombination of vacuum fluorescent illumination, LEDs andincandescent lamps.

HVAC control module, head assemblyRear HVAC control module, head assemblyRadioRear seat audioThe instrument panel clusterThe PRNDL lamp, with the exception of the current gear selectpositionPower window switchesVarious switches

When the ignition switch is turned to the ON position, thevacuum fluorescent display, radio, turns ON at maximum brightness.When the park lamps or low beams are ON, all incandescent backlighting turn ON at the dimming level indicated by the instrumentpanel cluster dimmer switch. At the same time all fluorescentdisplay displays dim to match the indicated dimming level. When theheadlamp switch is placed in the PARK or in HEADLAMPS position, theheadlamp switch supplies an input signal to the BCM. The BCM thensupplies voltage to the instrument panel cluster dimmer switchthrough the dimming control circuit. The setting of the instrumentpanel cluster dimmer switch determines the amount of voltage thatthe instrument panel cluster dimmer switch supplies to the BCM. TheBCM then sends a PWM voltage to all the interior lamps. All thefluorescent display and incandescent back lighting lamps areprovided a specific voltage.

Note:For vehicles which are equipped with automatic lightfunction, the interior backlighting can only be dimmed when theambient light sensor detects night conditions.

When the headlight switch is turned to the park lamp orheadlamp position, all incandescent back lighting turn ON at thedimming level indicated by the instrument panel cluster dimmerswitch. When the instrument panel cluster dimmer switch is movedfrom minimum to maximum, all fluorescent display displays, as wellas all incandescent back lighting respond from minimum intensity tomaximum brightness in response to the instrument panel clusterdimmer switch.

Inadvertent Power

The BCM used in this vehicle controls the lighting systemthrough circuits that enable the interior lamps. The BCM opensthese enabling circuits shortly after the ignition switch is turnedOFF with no lamp switch activity. If the ignition switch is turnedto any position other than OFF, or if a lamp switch is activatedduring this period, the timer will reset itself.