OPERATION
The electronic gear selector indicator gives an indication to the vehicle operator of the transmission gear that has
been selected with the automatic transmission gear selector lever. This indicator is controlled by the instrument clus-
ter circuit board based upon cluster programming and electronic messages received from the Powertrain Control
Module (PCM) over the Controller Area Network (CAN) data bus.
The gear selector indicator information is displayed by the odometer/trip odometer Vacuum Fluorescent Display
(VFD) unit soldered onto the instrument cluster electronic circuit board, and the VFD will not display the gear selec-
tor indicator information after the ignition switch is turned to the Off position. Each time the cluster is disconnected
from battery current for more than about five minutes, it must configure itself for the automatic transmission model
that is in the vehicle once it is reconnected to battery current. The instrument cluster circuitry operates the gear
selector indicator to provide the following features:
•
Selected Gear Message - Each time the cluster receives a selected gear message from the PCM, a box will
be illuminated around the appropriate character in the gear selector indicator. The box will remain illuminated
until the cluster receives a different selected gear message, or until the ignition switch is turned to the Off
position, whichever occurs first.
•
Communication Error - If the cluster fails to receive a selected gear message from the PCM within three
seconds, the instrument cluster circuitry will display all gear selector positions boxed (selected) until a valid
selected gear message is received or until the ignition switch is turned to the Off position, whichever occurs
first.
•
Actuator Test - Each time the cluster is put through the actuator test, the odometer/trip odometer VFD will
display all of its characters at once, then step through each character segment individually during the VFD
portion of the test to confirm the functionality of the VFD and the cluster control circuitry.
The PCM continually monitors a hard wired multiplex input from the Transmission Range Sensor (TRS), then sends
the proper selected gear messages to the instrument cluster. For further diagnosis of the gear selector indicator or
the instrument cluster circuitry that controls this function, (Refer to 8 - ELECTRICAL/INSTRUMENT CLUSTER -
DIAGNOSIS AND TESTING).
For proper diagnosis of the TRS, the PCM, the CAN data bus, or the electronic message inputs to the instrument
cluster that control the gear selector indicator, a diagnostic scan tool is required. Refer to the appropriate diagnostic
information.
HIGH BEAM INDICATOR
DESCRIPTION
A high beam indicator is standard equipment on all
instrument clusters. This indicator is located near the
upper edge of the instrument cluster, between the
minor gauge set and the speedometer.
The high beam indicator consists of a stencil-like cutout of the International Control and Display Symbol icon for
“High Beam” 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 blue Light Emitting Diode (LED) behind the cutout in
the opaque layer of the overlay causes the icon to appear in blue 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 high beam indicator is serviced as a unit with the instrument cluster.
OPERATION
The high beam indicator gives an indication to the vehicle operator whenever the headlamp high beams are illumi-
nated. This indicator is controlled by a transistor on the instrument cluster circuit board based upon cluster pro-
gramming and a hard wired multiplex input received by the cluster from the headlamp beam select switch circuitry
of the multi-function switch on the washer/beam select switch mux circuit.
The high beam 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
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CLUSTER
ND