Commander 4WD V8-4.7L Flex Fuel (2009)
when it is illuminated by the instrument cluster electronic circuit board.
The check gauges indicator is serviced as a unit with the OLED in the instrument cluster.
Check Gauges Indicator - Operation
OPERATION
The check gauges indicator gives an indication to the vehicle operator when the engine coolant temperature gauge indicates the coolant temperature is
high or critical. This indicator is controlled by the instrument cluster logic circuit based upon cluster programming and electronic messages received over
the Controller Area Network (CAN) data bus from the Powertrain Control Module (PCM).
The check gauges indicator function of the reconfigurable dot matrix Organic Light Emitting Diode (OLED) display unit is completely controlled by the
instrument cluster logic circuit, and that logic will only allow this indicator to operate when the instrument cluster receives a battery current input on the
fused ignition switch output (run-start) circuit. Therefore, the OLED check gauges indication will always be OFF when the ignition switch is in any
position except ON or START. The instrument cluster will turn ON the check gauges indicator for the following reasons:
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Engine Temperature High or Critical Message - Each time the cluster receives an electronic engine coolant temperature message from the
PCM indicating the temperature is high [at or above about 127° C (261° F) for gasoline engines, or about 128° C (262° F) for diesel engines], or
critical [above about 132° C (270° F)] the engine coolant temperatures gauge needle is moved to the appropriate position at the high end of the
gauge scale, the check gauges textual warning is displayed, and a single chime tone is sounded. The check gauges textual warning remains
illuminated until the cluster receives a message from the PCM indicating that the temperature is below about 124° C (255° F), until the cluster
arbitrator logic determines that another display request has priority, or until the ignition switch is turned to the OFF position, whichever occurs
first. The chime tone feature will only repeat during the same ignition cycle if the check gauges textual warning is cycled OFF and then ON again
by the appropriate temperature messages from the PCM.
The PCM continually monitors the engine coolant temperature sensor to determine the engine operating temperature. The PCM then sends the proper
messages to the instrument cluster, also known as the Cab Compartment Node (CCN). If the instrument cluster turns on the check gauges indicator due to
a high or critical engine temperature gauge reading, it may indicate that the engine or the engine cooling system requires service.
For proper diagnosis of the engine coolant temperature sensor, the PCM, the CCN, the CAN data bus or the electronic communication related to check
gauges indicator operation a diagnostic scan tool is required. Refer to the appropriate diagnostic information.
Hill Descent Indicator - Description
DESCRIPTION
A hill descent control indicator is standard equipment on all instrument clusters. However, on vehicles not equipped with an optional QuadraDrive
four-wheel drive system this indicator is electronically disabled. The hill descent indication appears within the reconfigurable dot matrix Organic Light
Emitting Diode (OLED) display unit. The hill descent indicator consists of a textual HILL DESCENT CONTROL message which appears in place of
the compass/trip computer information in the dot matrix display.
The dot matrix OLED is soldered onto the cluster electronic circuit board, and is visible through a window with a smoked clear lens located on the lower
edge of the tachometer gauge dial face of the cluster overlay. The dark lens over the OLED prevents it from being clearly visible when it is not
illuminated. The hill descent textual message appears in the same white color and at the same lighting level as the compass/trip computer information
when it is illuminated by the instrument cluster electronic circuit board.
The hill descent indicator is serviced as a unit with the OLED in the instrument cluster.
Hill Descent Indicator - Operation
OPERATION
The hill descent indicator gives an indication to the vehicle operator when the QuadraDrive four-wheel drive transfer case gear selector is in the 4WD
LOW position and the hill descent control push button in the instrument panel switch pod has been depressed to turn the feature ON. This feature uses
the grade sensing logic of the Controller Antilock Brake (CAB) to sense the vehicle is descending a hill and employs the brake system to automatically
control the hill descent speed of the vehicle. This indicator is controlled by the instrument cluster logic circuit based upon cluster programming and
electronic messages received over the Controller Area Network (CAN) data bus from the CAB.
The hill descent indicator function of the reconfigurable dot matrix Organic Light Emitting Diode (OLED) display unit is completely controlled by the
instrument cluster logic circuit, and that logic will only allow this indicator to operate when the instrument cluster receives a battery current input on the
fused ignition switch output (run-start) circuit. Therefore, the OLED hill descent indication will always be OFF when the ignition switch is in any
position except ON or START. The instrument cluster will turn ON the hill descent indicator for the following reasons:
