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Home >> Dodge or Ram Truck >> 2001 >> Durango 4WD V8-5.9L VIN Z LDC >> Repair and Diagnosis >> Instrument Panel, Gauges and Warning Indicators >> Instrument Cluster / Carrier >> Description and Operation >> Detailed Description >> Part 4 of 8

Part 4 of 8

DOOR AJAR INDICATOR
A door ajar indicator is standard equipment on all instrument clusters. However, on vehicles not equipped with this optional feature, this indicator is electronically disabled. The door ajar indicator is located in the Information Center area of the instrument cluster, to the left of center. The door ajar indicator consists of a stenciled cutout of the words "DOOR AJAR" 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 red lens behind the cutout in the opaque layer of the overlay causes the "DOOR AJAR" text to appear in red through the translucent outer layer of the overlay when the indicator is illuminated from behind by a Light Emitting Diode (LED) soldered onto the instrument cluster electronic circuit board. The door ajar indicator is serviced as a unit with the instrument cluster.

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 electronic messages received by the cluster from the Central Timer Module (CTM) over the Programmable Communications Interface (PCI) data bus. The door ajar indicator Light Emitting Diode (LED) receives battery current on the instrument cluster electronic circuit board through the fused ignition switch output (run-start) circuit whenever the ignition switch is in the ON or Start positions; 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:

- Bulb Test - Each time the ignition switch is turned to the ON position the door ajar indicator is illuminated for about two seconds as a bulb test.

- Door Ajar Lamp-ON Message - Each time the cluster receives a door ajar lamp-ON message from the CTM indicating that a door is open or not completely latched, the door ajar indicator will be illuminated. The indicator remains illuminated until the cluster receives an door ajar lamp-OFF message from the CTM, 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 cluster control circuitry.

The CTM continually monitors the door ajar switches to determine the status of the doors. The CTM then sends the proper door ajar lamp-ON and lamp-OFF messages to the instrument cluster. For further diagnosis of the door ajar indicator or the instrument cluster circuitry that controls the indicator, (Refer to INSTRUMENT CLUSTER - DIAGNOSIS AND TESTING). For proper diagnosis of the door ajar switches and circuits, (Refer to LAMPS/LIGHTING - INTERIOR/DOOR AJAR SWITCH DIAGNOSIS AND TESTING). For proper diagnosis of the CTM, the PCI data bus, or the message inputs to the instrument cluster that control the door ajar indicator, a DRB III scan tool is required. Refer to the appropriate diagnostic information.

ENGINE TEMPERATURE GAUGE
An engine coolant temperature gauge is standard equipment on all instrument clusters. The engine coolant temperature gauge is located in the lower left quadrant of the instrument cluster, below the voltage gauge. The engine coolant temperature gauge consists of a movable gauge needle or pointer controlled by the instrument cluster circuitry and a fixed 90 degree scale on the cluster overlay that reads left-to-right from "C" (or Cold) to "H" (or Hot) for all engines. An International Control and Display Symbol icon for "Engine Coolant Temperature" is located on the cluster overlay, in the center of the gauge directly above the hub of the gauge needle. The engine coolant temperature gauge graphics are white against a black 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 illuminated from behind by the panel lamps dimmer controlled cluster illumination lighting with the exterior lamps turned ON, the white graphics appear blue-green and the red graphics appear red. The orange gauge needle is internally illuminated. Gauge illumination is provided by replaceable incandescent bulb and bulb holder units located on the instrument cluster electronic circuit board. The engine coolant temperature gauge is serviced as a unit with the instrument cluster.

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 messages received by the cluster from the Powertrain Control Module (PCM) over the Programmable Communications Interface (PCI) data bus. The engine coolant temperature gauge is an air core magnetic unit that receives battery current on the instrument cluster electronic circuit board through the fused ignition switch output (run-start) circuit whenever the ignition switch is in the ON or Start positions. The cluster is programmed to move the gauge needle back to the low end of the scale after the ignition switch is turned to the OFF position. The instrument cluster circuitry controls the gauge needle position and provides the following features:

- Engine Temperature Message - Each time the cluster receives a message from the PCM indicating the engine coolant temperature is between the low end of normal [about 54 °C (130 °F) and the high end of normal [about 129 °C (264 °F), the gauge needle is moved to the actual temperature position on the gauge scale.

- Engine Temperature Low Message - Each time the cluster receives a message from the PCM indicating the engine coolant temperature is below the low end of normal [about 54 °C (130 °F)], the gauge needle is held at the "C" increment at the far left end of the gauge scale. The gauge needle remains at the far left end of the scale until the cluster receives a message from the PCM indicating that the engine temperature is above about 54 °C (130 °F), or until the ignition switch is turned to the OFF position, whichever occurs first.

- Engine Temperature High Message - Each time the cluster receives a message from the PCM indicating the engine coolant temperature is above about 122 °C (251 °F), the gauge needle is moved to the appropriate position on the gauge scale, the check gauges indicator is illuminated, and a single chime tone is sounded. The check gauges indicator remains illuminated until the cluster receives a message from the PCM indicating that the engine temperature is below about 119 °C (246 °F), 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 indicator is cycled OFF and then on again by the appropriate engine temperature messages from the PCM.

- Message Failure - If the cluster fails to receive an engine temperature message, it will hold the gauge needle at the last indication until a new 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 gauge needle will be swept to several calibration points on the gauge scale in a prescribed sequence in order to confirm the functionality of the gauge and the cluster control circuitry.

The PCM continually monitors the engine coolant temperature sensor to determine the engine operating temperature. The PCM then sends the proper engine coolant temperature messages to the instrument cluster. For further diagnosis of the engine coolant temperature gauge or the instrument cluster circuitry that controls the gauge, (Refer to INSTRUMENT CLUSTER - DIAGNOSIS AND TESTING). If the instrument cluster turns ON the check gauges indicator due to a high 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 PCI data bus, or the message inputs to the instrument cluster that control the engine coolant temperature gauge, a DRB III scan tool is required. Refer to the appropriate diagnostic information.
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