•
Turn Signal-On Input - Each time the cluster detects a turn signal-on input from the turn signal switch circuitry
of the multi-function switch on the turn/hazard switch mux circuit, it sends the appropriate electronic turn signal
switch status messages to the FCM over the PCI data bus. The FCM responds to these messages by con-
trolling a battery voltage output and the flash rate for either the right or left turn signal lamps. The FCM also
sends the appropriate electronic messages back to the EMIC to control the illumination and flash rate of the
right or left turn signal indicators, as well as to control the click rate of an electromechanical relay soldered
onto the EMIC electronic circuit board that emulates the sound emitted by a conventional turn signal flasher.
The turn signals and the turn signal indicators continue to flash on and off until the cluster receives a turn
signal-off input from the multi-function switch, or until the ignition switch is turned to the Off position, whichever
occurs first.
•
Hazard Warning-On Input - Each time the cluster detects a hazard warning-on input from the hazard warning
switch circuitry of the multi-function switch on the turn/hazard switch mux circuit, it sends the appropriate elec-
tronic hazard switch status messages to the FCM over the PCI data bus. The FCM responds to these mes-
sages by controlling a battery voltage output and the flash rate for each of the right and left turn signal lamps.
The FCM also sends the appropriate electronic messages back to the EMIC to control the illumination and
flash rate of the right and left turn signal indicators, as well as to control the click rate of an electromechanical
relay soldered onto the EMIC electronic circuit board that emulates the sound emitted by a conventional haz-
ard warning flasher. The turn signals and the turn signal indicators continue to flash on and off until the cluster
receives a hazard warning-off input from the multi-function switch.
•
Lamp Out Mode - The instrument cluster also sends electronic turn signal on and off messages to the FCM
over the PCI data bus, and the FCM flashes the appropriate exterior turn signal lamps. If the FCM detects an
inoperative turn signal lamp or circuit, it increases the flash rate for the remaining operative turn signals and
sends an electronic message back to the instrument cluster. The instrument cluster then increases the flash
rate of the turn signal indicator(s) and the clicking rate of the electromechanical relay to provide an indication
of the problem to the vehicle operator.
•
Actuator Test - Each time the cluster is put through the actuator test, the turn signal indicators will be turned
on, then off again during the bulb check portion of the test to confirm the functionality of each LED and the
cluster control circuitry.
The instrument cluster continually monitors the multi-function switch and electronic messages from the FCM to
determine the proper turn signal and hazard warning system control. For further diagnosis of the turn signal indi-
cators or the instrument cluster circuitry that controls the indicators, (Refer to 8 - ELECTRICAL/INSTRUMENT
CLUSTER - DIAGNOSIS AND TESTING).
For proper diagnosis of the turn signal and hazard warning system, the multi-function switch, the FCM, the PCI data
bus, or the electronic message inputs to the instrument cluster that control the turn signal indicators, a diagnostic
scan tool is required. Refer to the appropriate diagnostic information.
UPSHIFT INDICATOR
DESCRIPTION
An upshift indicator is standard equipment on all
instrument
clusters.
However,
on
vehicles
not
equipped with a manual transmission, or on vehicles
equipped with a manual transmission but sold in a
market where this is not required equipment, this indi-
cator is electronically disabled.
The upshift indicator consists of an upward pointed arrow icon, which appears on the right side of the electronic
gear selector indicator Vacuum Fluorescent Display (VFD) unit. The VFD is soldered onto the cluster electronic cir-
cuit board and is visible through a window with a smoked clear lens located on the lower edge of the speedometer
gauge dial face of the cluster overlay. The dark lens over the VFD prevents the indicator from being clearly visible
when it is not illuminated. The icon appears in a blue-green color and at the same lighting level as the odometer/trip
odometer information when it is illuminated by the instrument cluster electronic circuit board. The upshift indicator is
serviced as a unit with the instrument cluster.
8J - 148
INSTRUMENT CLUSTER -SERVICE INFORMATION
DR/DH