Raider V6-3.7L SOHC (2006)
Fog/Driving Lamp Indicator: Description and Operation
FOG LAMP INDICATOR
DESCRIPTION
A fog lamp indicator is standard equipment on all instrument clusters. However, on vehicles not equipped with optional fog lamps, this indicator is
electronically disabled. This indicator is located near the upper edge of the instrument cluster, between the minor gauge set and the speedometer.
The fog lamp indicator consists of a stencil-like cutout of the International Control and Display Symbol icon for "Front Fog Light" in the opaque layer of
the instrument cluster overlay. The dark outer layer of the overlay prevents the indicator from being clearly visible when it is not illuminated. A green
Light Emitting Diode (LED) behind the cutout in the opaque layer of the overlay causes the icon to appear in green through the translucent outer layer of
the overlay when the indicator is illuminated from behind by the LED, which is soldered onto the instrument cluster electronic circuit board. The fog
lamp indicator is serviced as a unit with the instrument cluster.
OPERATION
The fog lamp indicator gives an indication to the vehicle operator whenever the optional fog lamps are illuminated. This indicator is controlled by a
transistor on the instrument cluster circuit board based upon cluster programming and electronic messages received by the cluster from the Front Control
Module (FCM) (also known as the Integrated Power Module/IPM) over the Controller Area Network (CAN) data bus.
The fog lamp indicator Light Emitting Diode (LED) is completely controlled by the instrument cluster logic circuit, and that logic will allow this
indicator to operate whenever the instrument cluster receives a battery current input on the fused B(+) circuit. Therefore, the LED can be illuminated
regardless of the ignition switch position. The LED only illuminates when it is provided a path to ground by the instrument cluster transistor. The
instrument cluster will turn on the fog lamp indicator for the following reasons:
-
Fog Lamp-On Message - Each time the cluster receives a fog lamp-on message from the FCM indicating the fog lamp relay is energized, the fog
lamp indicator will be illuminated. The indicator remains illuminated until the cluster receives a fog lamp-off message from the FCM.
-
Actuator Test - Each time the cluster is put through the actuator test, the fog lamp indicator will be turned on, then off again during the bulb
check portion of the test to confirm the functionality of the LED and the cluster control circuitry.
The instrument cluster continually monitors a hard wired input from the headlamp switch to determine the selected fog lamp switch status. The
instrument cluster then sends the proper fog lamp-on and lamp-off messages to the FCM over the CAN data bus. The FCM activates the fog lamp relay
then sends the proper fog lamp indicator lamp-on and lamp-off messages to the instrument cluster. For further diagnosis of the fog lamp indicator or the
instrument cluster circuitry that controls the indicator.
For proper diagnosis of the fog lamp system, the FCM, the CAN data bus, or the electronic message inputs to the instrument cluster that control the fog
lamp indicator, a diagnostic scan tool is required. Refer to the appropriate diagnostic information.
