indicator from being clearly visible when it is not illuminated. A red Light Emitting Diode (LED) behind the cutout in
the opaque layer of the overlay causes the icon to appear in red 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 door ajar indicator is serviced as a unit with the instrument cluster.
OPERATION
The door ajar indicator gives an indication to the vehicle operator that one or more of the passenger compartment
doors may be open or not completely latched. This indicator is controlled by a transistor on the instrument cluster
circuit board based upon cluster programming and hard wired inputs received by the cluster from the door ajar
switches located in each door latch unit.
The door ajar 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 ignition switch output (run-start) circuit. Therefore, the LED will always be off when the ignition switch is
in any position except On or Start. The LED only illuminates when it is provided a path to ground by the instrument
cluster transistor. The instrument cluster will turn on the door ajar indicator for the following reasons:
•
Door Ajar Switch Input - Each time the cluster detects ground on any one of the door ajar switch sense
circuits (door ajar switch closed = door is open or not completely latched) the door ajar indicator will be illu-
minated. The indicator remains illuminated until all of the door ajar switch sense inputs to the cluster are an
open circuit (door ajar switch open = door fully closed), until the cluster has completed an interior lamps load
shed (about five minutes), 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 door ajar 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 the door ajar switches to determine the status of the doors. For further
diagnosis of the door ajar indicator or the instrument cluster circuitry that controls the indicator, (Refer to 8 - ELEC-
TRICAL/INSTRUMENT CLUSTER - DIAGNOSIS AND TESTING).
For proper diagnosis of the door ajar switches and circuits, refer to the appropriate wiring information.
ENGINE TEMPERATURE GAUGE
DESCRIPTION
An engine coolant temperature gauge is standard
equipment on all instrument clusters. This gauge is
part of the minor gauge set with the fuel gauge
located on the left side of the instrument cluster, just
left of the speedometer. The gauge consists of a movable gauge needle or pointer controlled by the instrument
cluster circuitry and a fixed 90 degree gauge scale on the cluster overlay that reads bottom-to-top from “C” (or Cold)
to “H” (or Hot). An International Control and Display Symbol icon for “Engine Coolant Temperature” is located on the
cluster overlay, directly below the bottom end of the scale.
The engine coolant temperature gauge graphics are black against a white field except for a single red graduation at
the high end of the gauge scale, making them clearly visible within the instrument cluster in daylight. When illumi-
nated from behind by the panel lamps dimmer controlled cluster illumination lighting with the exterior lamps turned
On, the white gauge dial face appears blue-green with the black graphics silhouetted against the illuminated back-
ground and the red graphics and the red gauge needle still appear red. Gauge illumination is provided by an integral
electro-luminescent lamp that is serviced as a unit with the instrument cluster. The engine coolant temperature
gauge is serviced as a unit with the instrument cluster.
OPERATION
The engine coolant temperature gauge gives an indication to the vehicle operator of the engine coolant temperature.
This gauge is controlled by the instrument cluster circuit board based upon cluster programming and electronic mes-
sages received by the cluster from the Powertrain Control Module (PCM) over the Controller Area Network (CAN)
data bus.
HB
CLUSTER
8J - 53