The head up display (HUD) is a secondary display system
that reflects vehicle information onto the windshield. The HUD system consists
of the following:
| • | the vehicle speed display |
Indicator Displays
The HUD displays the following:
| • | the CHECK GAGES indicator |
| • | the high beam indicator |
| • | the km/h (MPH) indicator |
| • | the turn signal indicators |
Refer to
Indicator/Warning Message Description and Operation
.
Vehicle Speed Display
The HUD displays the vehicle speed based on information from the vehicle
speed sensor. The PCM converts the data from the vehicle speed sensor to a
4000 pulses/mile signal. The HUD uses the vehicle speed signal circuit
(4000 pulses/mile) from the PCM in order to calculate the vehicle
speed. The HUD displays either miles or kilometers as requested by the activation
of the English/metric button in the DIC switch. The associated indicator
(km/h or MPH) illuminates.
Radio Display
The HUD displays the following radio information:
| • | the radio frequency and the band |
| • | the CD disc (for multiple changer) and the CD track |
The HUD receives class 2 messages from the radio indicating the
display mode, the frequency, the band, and the CD track. The HUD receives
a class 2 message from the remote playback device - CD changer
indicating the current CD disc number and the CD track.
Control Switches
The HUD switch consists of the following controls:
| • | the image adjustment switch |
| • | the display dimming switch |
The image adjustment switch controls the electric tilt adjust within
the HUD. The image adjustment switch is hard wired to the motor within the
HUD in order to move the HUD image vertically on the windshield. When the
switch is in the up position, the HUD image up control circuit provides
voltage to the motor and the HUD image down control circuit provides the
ground. When the switch is in the down position, the HUD image down control
circuit provides voltage to the motor and the HUD image up control circuit
provides the ground.
The HUD brightness is manually adjusted by turning the display dimming
switch. Turn the switch all the way to the left in order to turn off the HUD
display. Turn the switch all the way to the right for maximum display brightness.
The instrument panel integration module (IPM) (with CJ2) or the HVAC control
module (with C67) monitors the ambient light sensor. The HUD receives
a class 2 message from the IPM or the HVAC control module indicating
the brightness level. When it is determined that it is daytime, the HUD
uses both the integrated HUD photocell and the display dimming switch in
order to control the dimming. If it is determined that it is nighttime,
the HUD uses the display dimming switch only in order to control the dimming.
