Principles of Operation

WARNING: This page is about a different car, the 2004 Mercury Mountaineer and 2004 Ford Explorer. However, it is still accessible from the selected car via links, so may be relevant.

The instrument cluster controls the following warnings and chimes:

driver or passenger safety belt not fastened warning chime (warning times out)
key-in -ignition warning (repetitive chime)
headlamp-on warning (repetitive chime)
door ajar warning (repetitive chime)
safety belt warning chime (repetitive chime)
belt minder warning chime (repetitive chime after a delay and the safety belt chime has completed)

The safety belt warning chime warns that the safety belt is not fastened. The safety belt warning chime sounds when the driver or passenger safety belt is not fastened and the key is turned from the OFF/LOCK, or ACC, to the RUN or START position.

The safety belt warning chime stops sounding when the safety belt is fastened, when the key is switched from the RUN or START to the OFF/LOCK or ACC position, or when the chime has sounded for approximately six seconds.

The safety belt warning chime inputs are:

ignition switch START position, voltage applied on START circuit 489 (PK/BK)
ignition switch RUN position, voltage applied on RUN circuit 295 (LB/PK)
driver or passenger safety belt switch data communicated by the restraint control module (RCM) to the instrument cluster on circuit 1390 (DB)

The safety belt warning lamp, along with the chime, warns that the safety belt is not fastened. The safety belt warning lamp is illuminated when the safety belt is not fastened and the key is turned from the OFF/LOCK or ACC to the RUN or START position.

The safety belt warning lamp turns off when the safety belt is fastened, the key is moved from the RUN or START to the OFF/LOCK or ACC position, or if the lamp is illuminated for approximately 6 seconds.

The safety belt warning lamp inputs are:

ignition switch START position, voltage applied on START circuit 489 (PK/BK)
ignition switch RUN position, voltage applied on RUN circuit 295 (LB/PK)
driver or passenger safety belt switch data communicated by the RCM to the instrument cluster on circuit 1390 (DB)

NOTE: The belt minder is configurable. For additional information, refer to MODULE COMMUNICATIONS NETWORK . To configure without using a diagnostic tool, refer to BELT MINDER DEACTIVATING/ACTIVATING .

The belt minder feature supplements the current safety belt warning function. The belt minder is enabled after the current safety belt warning is complete. The belt minder reminds the driver that the driver or passenger safety belt is unbuckled by intermittently sounding a chime and illuminating the safety belt warning lamp in the instrument cluster. While activated, the belt minder alternates the chime and indicator from on for 6 seconds to off for 30 seconds.

The door ajar warning chime warns that a door is not fully closed. The chime sounds when any door or the liftgate becomes ajar while the key is in the RUN position.

The door ajar warning indicator warns that a door is not fully closed. The door ajar warning indicator illuminates when any door or the liftgate initially becomes ajar while the key is in the RUN or START position.

The door ajar warning indicator turns off when all doors and the liftgate are closed, or the key is turned to the OFF/LOCK or ACC position.

The door ajar warning lamp/chime inputs are:

ignition switch START position, voltage applied on START circuit 489 (PK/BK)
ignition switch RUN position, voltage applied on RUN circuit 295 (LB/PK)
door ajar data communicated by the vehicle security module to the instrument cluster on the UBP communication circuit 693 (OG)

The key-in-ignition warning chime warns that the key is still in the ignition when the driver door is ajar. The key-in-ignition warning chime sounds when the driver door is ajar, the ignition switch is in the OFF/LOCK or ACC position and the key is in the ignition.

The key-in-ignition warning chime stops sounding when the driver door is closed, the key is removed from the ignition, or if the key is turned to the RUN position.

The key-in-ignition warning chime inputs are:

ignition switch START position, no voltage on START circuit 489 (PK/BK)
ignition switch RUN position, no voltage on RUN circuit 295 (LB/PK)
key-in-ignition switch circuit 1414 (LG/VT), voltage applied with key in ignition

The headlamp on warning chime warns that the headlamps are on when the driver door is ajar and the key is removed from the ignition. The headlamps on warning chime sounds if the driver door is ajar, the headlamp switch is in the PARK or HEAD position, and the ignition switch is in the OFF/LOCK position with the key out.

The headlamp on warning chime stops sounding when any one of the above conditions are removed.

The headlamp on warning chime inputs are:

ignition switch START position, no voltage on START circuit 489 (PK/BK)
ignition switch RUN position, no voltage on RUN circuit 295 (LB/PK)
key-in -ignition switch circuit 1414 (LG/VT), no voltage applied with key removed from the ignition
voltage applied on the instrument illumination circuit 235 (RD/BK)

The turn signal left on warning chime warns that the turn signal has not cancelled. The turn signal left on warning chime sounds if the left or right turn signal is on and the vehicle has traveled for more than 0.8 km (0.5 miles).

The turn signal left on warning chime stops sounding if the turn signal is turned off or if the ignition switch is in the OFF or ACCESSORY position.

The turn signal left on warning chime inputs are:

Turn signal data received by the instrument cluster from the multifunction switch when it is in the LH or RH turn positions.
Odometer count data communicated by the powertrain control module (PCM) to the instrument cluster through the communication network.