Dakota 4WD V8-5.2L VIN Y (1998)
Malfunction Lamp / Indicator: Description and Operation
SYSTEM OPERATION
Airbag Indicator Lamp
The airbag indicator lamp gives an indication when the airbag system is faulty or inoperative. The lamp is controlled by the instrument cluster
circuitry based upon messages received from the Airbag Control Module (ACM) on the Chrysler Collision Detection (CCD) data bus. The lamp is
turned on by the ACM for about seven seconds when the ignition switch is turned to the On position as a bulb test.
The ACM continually monitors the airbag system circuits and sensors to decide whether the system is in good operating condition. The ACM then
sends the proper messages to the instrument cluster on the CCD data bus to turn the lamp on or off. If the ACM turns the lamp on after the bulb
test, it indicates the ACM has detected a system malfunction and/or that the airbag system has become inoperative. The instrument cluster circuitry
will also send a chime request to the Central Tachometer Module (CTM) when a lamp-on message is received from the ACM. A lamp-on message
does not mean that either or both airbags will not deploy upon an impact, only that they might not deploy, depending upon the nature of the
detected malfunction. Each time that the instrument cluster circuitry receives a lamp-on message from the ACM, it will light the lamp for three
seconds or the duration of the airbag system malfunction, whichever is longer.
The airbag indicator lamp also has a lamp backup feature. About ten seconds after the ignition switch is turned to the On position, if an
inoperative airbag warning lamp circuit was detected during the bulb test sequence, the instrument cluster circuitry will flash the seat belt reminder
lamp on and off for about thirty seconds. If the seat belt reminder lamp stays on after flashing for thirty seconds, or comes on at any time other
than about ten seconds after the initial ignition-on sequence, it may indicate that an airbag system fault has been detected and that the airbag
indicator lamp is inoperative.
See Instrument Panel, Gauges and Warning Indicators/Seat Belt Reminder Lamp in the Description and Operation for more information on the
airbag lamp backup feature.
