Chrysler 300/300 Touring/300C, Dodge Magnum. Manual - part 488
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 transmission range indi-
cator or the instrument cluster circuitry that controls this function, (Refer to 8 - ELECTRICAL/INSTRUMENT CLUS-
TER - DIAGNOSIS AND TESTING). The Transmission Range indicator is serviced with the instrument cluster.
INDICATORS
Indicators are located in various positions within the EMIC and are all connected to the EMIC electronic circuit
board. The various EMIC indicators are controlled by different strategies; some receive fused ignition switch output
from the EMIC circuitry and have a switched ground, while others are grounded through the EMIC circuitry and have
a switched battery feed. However, all indicators are completely controlled by the EMIC microprocessor based upon
various hard wired and electronic message inputs. All indicators except those located within the VFD units are illu-
minated at a fixed intensity, which is not affected by the selected illumination intensity of the electro-luminescent
EMIC general illumination lamp. The illumination intensity of those within the VFD units is synchronized with that of
the EMIC general illumination lamp.
In addition, certain indicators in this instrument cluster are automatically configured or self-configured. This feature
allows the configurable indicators to be enabled by the EMIC circuitry for compatibility with certain optional equip-
ment. The EMIC defaults for the ABS indicator and airbag indicator are enabled, and these configuration settings
must be programmatically disabled in the EMIC using a diagnostic scan tool for vehicles that do not have this equip-
ment. The automatically configured or self-configured indicators remain latent in each EMIC at all times and will be
active only when the EMIC receives the appropriate CAN message inputs for that optional system or equipment.
ABS INDICATOR
The ABS indicator gives an indication to the vehicle
operator when the ABS system is faulty or inoperative.
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 Controller Antilock Brake (CAB) over the Controller Area Network (CAN) data bus.
The ABS indicator Light Emitting Diode (LED) 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 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 ABS indicator for the following reasons:
•
Bulb Test - Each time the ignition switch is turned to the On position the ABS indicator is illuminated for about
four seconds as a bulb test. The entire bulb test is a function of the CAB.
•
ABS Lamp-On Message - Each time the cluster receives a lamp-on message from the CAB, the ABS indi-
cator will be illuminated. The indicator remains illuminated until the cluster receives a lamp-off message from
the CAB, or until the ignition switch is turned to the Off position, whichever occurs first.
•
Communication Error - If the cluster receives no lamp-on or lamp-off messages from the CAB for five con-
secutive message cycles, the ABS indicator is illuminated. The indicator remains illuminated until the cluster
receives a valid message from the CAB, or until the ignition switch is turned to the Off position, whichever
occurs first.
•
Actuator Test - Each time the instrument cluster is put through the actuator test, the ABS 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.
•
ABS Diagnostic Test - The ABS indicator is blinked on and off by lamp-on and lamp-off messages from the
CAB during the performance of the ABS diagnostic tests.
The CAB continually monitors the ABS circuits and sensors to decide whether the system is in good operating con-
dition. The CAB then sends the proper lamp-on or lamp-off messages to the instrument cluster. If the CAB sends a
lamp-on message after the bulb test, it indicates that the CAB has detected a system malfunction and/or that the
ABS system has become inoperative. The CAB will store a Diagnostic Trouble Code (DTC) for any malfunction it
detects. Each time the ABS indicator fails to light due to an open or short in the cluster ABS indicator circuit, the
cluster sends a message notifying the CAB of the condition, then the instrument cluster and the CAB will each store
a DTC. The ABS indicator is serviced with the instrument cluster.
8J - 56
INSTRUMENT CLUSTER - SERVICE INFORMATION
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