Town & Country V6-3.8L (2009)
Security Lamp/Indicator: Description and Operation
Security System Indicator - Operation
OPERATION
The security indicator gives an indication to the vehicle operator when the Vehicle Theft Security System (VTSS) is arming or is armed. On vehicles
equipped with the Sentry Key Immobilizer System (SKIS), the security indicator also gives an indication to the vehicle operator of the status of the
SKIS. This indicator is controlled by a transistor on the instrument cluster circuit board based upon cluster programming, and electronic security
indicator request messages received by the cluster from the Totally Integrated Power Module (TIPM) or the Wireless Ignition Node (WIN), over the
Controller Area Network (CAN) data bus.
The security 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 B(+) circuit. Therefore, the LED can be illuminated regardless of
the ignition switch position. The LED only illuminates when it is provided a path to ground by the instrument cluster transistor. Depending upon the
programmed condition, the indicator can be illuminated solid, flashed at a slow rate (0.5 Hertz, 12.5 percent duty cycle), or flashed at a fast rate (1 Hertz,
50 percent duty cycle). The instrument cluster will turn ON the security indicator for the following reasons:
-
Bulb Test - Each time the ignition switch is turned to the ON position the security indicator illuminates for about two seconds as a bulb test. The
entire bulb test is a function of the WIN.
-
Security Indicator Lamp-On Message - During the 16 second VTSS arming function, the TIPM will request the cluster flash the security
indicator ON and OFF repeatedly at a steady, fast rate to indicate that the VTSS is in the process of arming. Following successful VTSS arming,
the TIPM will request the cluster flash the security indicator ON and OFF continuously at a slower rate to indicate that the VTSS is armed. The
security indicator continues flashing at the slower rate until the VTSS is disarmed or triggered. If the VTSS has alarmed and rearmed, the TIPM
will request the cluster flash the security indicator at a steady, slow rate for about 30 seconds after the VTSS is disarmed.
-
SKIS Indicator Lamp-On Message - Each time the cluster receives an electronic SKIS indicator lamp-ON message from the WIN, the security
indicator will be illuminated. The indicator can be flashed ON and OFF, or illuminated solid, as dictated by the WIN message. The indicator
remains illuminated solid or continues to flash until the cluster receives a lamp-OFF message from the WIN, or until the ignition switch is turned
to the OFF position, whichever occurs first. For more information on the SKIS and the security indicator control parameters, See: Description and
Operation/Vehicle Theft Security System - Operation.
-
Communication Error - If the cluster receives no lamp-ON or lamp-OFF messages from the TIPM or the WIN for 10 consecutive message
cycles, the security indicator is illuminated by the instrument cluster. The indicator remains controlled and illuminated by the cluster until a valid
lamp-ON or lamp-OFF message is received from the WIN.
-
Actuator Test - Each time the instrument cluster is put through the actuator test, the security 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 TIPM sends electronic security indicator request messages to control the security indicator whenever the ignition switch is in the OFF position and
the VTSS is arming, armed, or alarming. Whenever the ignition switch is in the ON or START positions, the WIN performs a self-test to decide whether
the SKIS is in good operating condition and whether a valid key is present in the ignition lock cylinder. The WIN then sends the proper lamp-ON or
lamp-OFF message to the ElectroMechanical Instrument Cluster (EMIC) (also known as the Cab Compartment Node/CCN). If the cluster flashes the
security indicator upon ignition ON, or turns ON the security indicator solid after the bulb test, it indicates that a SKIS malfunction has occurred or that
the SKIS is ineffective.
For proper diagnosis of the VTSS, the SKIS, the WIN, the TIPM, the EMIC, the CAN data bus or the electronic communication related to security
indicator operation a diagnostic scan tool is required. Refer to the appropriate diagnostic information.
