SEATBELT INDICATOR

OPERATION

The seatbelt indicator gives an indication to the vehicle operator of the status of the driver and passenger side front seat belts. This indicator is controlled by a transistor on the instrument cluster circuit board based upon cluster programming. On vehicles equipped with airbags the indicator is also controlled by electronic messages received by the cluster from the Airbag Control Module (ACM) over the Programmable Communications Interface (PCI) data bus.

The seatbelt indicator also includes a programmable enhanced seatbelt reminder or BELTMINDER feature that is enabled when the vehicle is shipped from the factory. This BELTMINDER feature can be disabled and enabled by the customer using a specific programming event sequence, or by the dealer using a diagnostic scan tool.

The seatbelt 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 seatbelt indicator for the following reasons:

• Seatbelt Reminder Function - Each time the cluster receives a battery current input on the fused ignition switch output (run-start) circuit, the indicator will be illuminated as a seatbelt reminder for about seven seconds, or until the ignition switch is turned to the OFF position, whichever occurs first. This reminder function will occur regardless of the status of the seatbelt switch inputs to the cluster.
• Seat Belt Switch Input - Beltminder Active - Following the seatbelt reminder function on vehicles equipped with the Occupant Classification System (OCS), each time the cluster receives an input from the driver or passenger side front seatbelt switch indicating that a front seat belt is not fastened with the ignition switch in the START or ON positions, the indicator will be illuminated. The passenger side front seat belt switch input must be accompanied by electronic messages received from the Airbag Control Module (ACM) over the Programmable Communications Interface (PCI) data bus indicating that the passenger side front seat is occupied. On vehicles not equipped with the OCS, the cluster responds only to the driver side seatbelt switch input. In addition, if the front seat belt remains unbuckled about 60 seconds after the conclusion of the seatbelt reminder function with the vehicle speed greater than about 13 kilometers-per-hour (8 miles-per-hour), the seatbelt indicator will begin to cycle between flashing ON and OFF for 5 seconds, then lighting solid for 3 seconds. The seatbelt indicator will continue to cycle between flashing and solid illumination for 12 complete cycles, until the cluster receives no front seat belt switch input, or until the ignition switch is turned to the OFF position, whichever occurs first.
• Seat Belt Switch Input - Beltminder Inactive - Following the seatbelt reminder function on vehicles equipped with the OCS, each time the cluster receives an input from the driver or passenger side front seatbelt switch indicating that a front seat belt is not fastened with the ignition switch in the START or ON positions, the indicator will be illuminated. The passenger side front seatbelt switch input must be accompanied by electronic messages received from the ACM over the PCI data bus indicating that the passenger side front seat is occupied. On vehicles not equipped with the OCS, the cluster responds only to the driver side seatbelt switch input. The seatbelt indicator remains illuminated until the cluster receives no seatbelt switch input, 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 seatbelt 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 ElectroMechanical Instrument Cluster (EMIC) continually monitors the status of the front seatbelt switch inputs and electronic messages from the ACM to determine the appropriate seatbelt indicator operation.

For proper diagnosis of the seatbelt switches, the ACM, the OCS, the EMIC, the PCI data bus or the electronic communication related to seatbelt indicator operation a diagnostic scan tool is required. Refer to the appropriate diagnostic information.