Warning Devices: Overview Ford Explorer IV

The warning chime sounds to remind or alert the driver

1. to turn the headlamps off when exiting the vehicle.
2. to remove the ignition key when exiting the vehicle.
3. when a door becomes ajar.
4. to fasten the safety belt after starting the vehicle.
5. to turn off the turn signal.
6. to disengage the parking brake.
7. that a fault is present in the air bag warning indicator circuit.
8. when the message center displays a door ajar, tire pressure monitoring system (TPMS), and/or a low fuel level warning message.

The instrument cluster controls the warning chime function using various inputs to determine when to sound the warning chime. The warning chime sounds

1. if the headlamps are on with the key removed from the ignition lock cylinder and the driver door is ajar.
2. if the key is in the ignition lock cylinder in the OFF position and the driver door is ajar.
3. if a door is ajar and the ignition key is in the ON position.
4. if the safety belts are not fastened and the ignition key is in the ON position.
5. if the turn signal is on for more than 3.2 km (2 miles).
6. if the parking brake is engaged and the vehicle is moving at a speed higher than 5 km/h (3 mph).
7. if the ignition switch is in the ON position, a secondary air bag warning chime request is received from the restraints control module (RCM), and the instrument cluster determines a fault is present in the air bag warning indicator.
8. when the message center displays a door ajar, tire pressure monitoring system (TPMS), and/or a low fuel level warning message.

Audible signals are also provided to confirm operation of the following vehicle systems

1. Turn signal
2. Hazard signal

Special Tools Illustration Tool Name Tool Number 73III Automotive Meter 105-R0057 or equivalent Vehicle Communication Module (VCM) and Integrated Diagnostic System (IDS) software with appropriate hardware, or equivalent scan tool Flex Probe Kit 105-R025C or equivalent

Scheme 1

Scheme 2

Principles of Operation

The instrument cluster uses different chimes to alert the driver of various vehicle conditions as follows

1. Safety belt warning (repetitive chime)
2. Safety belt minder warning (repetitive chime after a delay and after the safety belt chime is completed)
3. Key-in-ignition warning (repetitive chime)
4. Headlamps on warning (repetitive chime)
5. Turn signal on warning (single tone chime after 3.2 km [2 miles])
6. Turn signal tone (tic-tock chime)
7. Parking brake warning (repetitive chime)
8. Air bag secondary warning chime (repetitive chime)
9. Message center general tone (single tone)

Safety Belt Warning Chime - 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 ignition key is turned from the OFF/LOCK or ACC to the ON or START position.

The safety belt warning chime stops sounding when the safety belt is fastened, when the ignition key is turned from the ON or START position to the OFF/LOCK or ACC position, or when the chime has sounded for approximately 6 seconds.

The safety belt warning chime inputs are

1. Ignition switch position
2. Driver or passenger safety belt switch data communicated by the restraints control module (RCM) to the instrument cluster through the controller area network (CAN)

Safety Belt Minder - The safety belt minder is configurable. To configure using a scan tool, refer to MODULE CONFIGURATION . To configure without using a scan tool, refer to Belt-Minder® Deactivating/Activating .

The safety belt minder feature supplements the current safety belt warning function. The safety belt minder is enabled after the current safety belt warning is complete. The safety 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 once the vehicle speed has exceeded 5 km/h (3 mph). While activated, the safety belt minder alternates the chime and indicator from on for 6 seconds to off for 60 seconds.

Note. The safety belt minder is disabled for 1 ignition switch ON cycle if the safety belt is buckled then unbuckled during that specific cycle.

Key-In-Ignition Warning Chime - The key-in-ignition warning chime warns that the key is still in the ignition lock cylinder when the driver door is ajar. The key-in-ignition warning chime sounds when the driver door is ajar, the key is in the ignition lock cylinder and in the OFF/LOCK or ACC position.

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

The key-in-ignition warning chime inputs are

1. Ignition switch position
2. Door ajar data communicated by the smart junction box (SJB) to the instrument cluster through the CAN
3. Key-in-ignition switch signal from the ignition switch

Headlamps On Warning Chime - The headlamps on warning chime warns that the headlamps are on when the driver door is ajar and the key is removed from the ignition lock cylinder. The headlamps on warning chime sounds if the driver door is ajar, the headlamp switch is in the headlamp or parking lamp on position, and the ignition switch in the OFF/LOCK position.

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

The headlamps on warning chime inputs are

1. Ignition switch position
2. Driver door ajar data communicated by the SJB to the instrument cluster through the CAN
3. Headlamp switch data communicated by the SJB to the instrument cluster through the CAN

Turn Signal On Warning Chime - The turn signal on warning chime warns that the turn signal has not been cancelled. The turn signal on warning chime sounds if the left or right turn signal is on and the vehicle has traveled more than 3.2 km (2 miles).

The turn signal on warning chime stops sounding if the turn signal is turned off, or if the ignition key is turned to the OFF or ACC position.

The turn signal on warning chime inputs are

1. Turn signal data communicated by the SJB to the instrument cluster through the CAN communication
2. Odometer count data communicated by the powertrain control module (PCM) to the instrument cluster through the CAN

Parking Brake Warning Chime - The parking brake warning chime warns that the parking brake is engaged when the vehicle is in motion. The parking brake warning chime sounds if the ignition key is in ON position, the parking brake is engaged, and the vehicle speed is greater than 5 km/h (3 mph).

The parking brake warning chime stops sounding if the parking brake is released, the ignition key is not in the ON position, or if the vehicle speed is less than 5 km/h (3 mph).

The parking brake warning chime inputs are

1. Ignition switch position
2. Parking brake switch data communicated by the SJB to the instrument cluster through the CAN
3. Vehicle speed data communicated by the PCM to the instrument cluster through the CAN

Air Bag Secondary Warning Chime - The air bag secondary warning chime warns that the air bag warning indicator light does not work correctly. The instrument cluster monitors the air bag warning indicator status internally. When a fault is present in the air bag warning indicator and the instrument cluster receives an air bag warning indicator on request from the RCM, the air bag secondary warning chime sounds.

The air bag secondary warning chime input is

1. Air bag warning indicator request data communicated by the RCM to the instrument cluster

Turn/Hazard On Tone - The turn/hazard on tone provides an audible signal in addition to the turn/hazard indicator lamps. The turn/hazard on tone sounds if the turn or hazard signals are on.

The turn/hazard on tone inputs are

1. Left turn indicator signal from the SJB to the instrument cluster
2. Right turn indicator signal from the SJB to the instrument cluster

Message Center Warning Chime - The message center warning chime sounds when a warning message is displayed on the message center. If multiple warning messages are present, a chime tone sounds for each of the warnings that are displayed. The message center warning chime inputs are the warning messages displayed on the message center. The message center warning chime sounds to alert the driver when a concern is detected in one of the following systems

1. Tire pressure monitoring system (TPMS)
2. Door ajar
3. Low fuel level

Normal Operation

When the key is inserted into the ignition lock cylinder, the key-in-ignition switch (part of the ignition switch) closes, providing a voltage signal to the instrument cluster through circuit CDC30 (BU/GY). The door ajar status is communicated to the instrument cluster from the smart junction box (SJB) through the communication area network (CAN). If the instrument cluster detects that the ignition switch is in the OFF or ACC position, the key is inserted in the ignition lock cylinder, and the SJB communicates to the instrument cluster that the driver door is ajar, the key-in-ignition warning chime sounds.

Possible Causes

1. Circuit CDC30 (BU/GY) open or short to ground
2. Key-in-ignition switch (part of the ignition switch)
3. Instrument cluster

The headlamps on warning chime sounds when the driver door is opened with the ignition switch in the OFF position, the key not in the ignition lock cylinder, and the headlamp switch in the headlamp or parking lamp ON position. The smart junction box (SJB) communicates to the instrument cluster when the headlamps or parking lamps are on and the driver door is opened. The autolamps feature must not be selected for the headlamps on warning chime to operate.

Possible Causes

1. Instrument cluster

The turn signal on warning chime sounds when the vehicle travels more than 3.2 km (2 miles) with the turn signal on. The smart junction box (SJB) communicates the turn signal switch status to the instrument cluster over the controller area network (CAN). The powertrain control module (PCM) communicates the odometer count data to the instrument cluster over the CAN.

Possible Causes

1. Turn signal indication
2. Vehicle speed input
3. Instrument cluster

When the key is inserted into the ignition lock cylinder, the key-in-ignition switch (part of the ignition switch) closes, providing a voltage signal to the instrument cluster through circuit CDC30 (BU/GY). The door ajar status is communicated to the instrument cluster from the smart junction box (SJB) through the communication area network (CAN). If the instrument cluster detects that the ignition switch is in the OFF or ACC position, the key is inserted in the ignition lock cylinder, and the SJB communicates to the instrument cluster that the driver door is ajar, the key-in-ignition warning chime sounds. The SJB communicates to the instrument cluster that the headlamps or parking lamps are on and the driver door is opened. The headlamps on warning chime sounds when the driver door is opened with the ignition switch in the OFF position, the key not in the ignition lock cylinder, and the headlamp switch in the headlamp or parking lamp ON position.

Possible Causes

1. Circuit CDC30 (BU/GY) short to voltage
2. Key-in-ignition warning switch (part of the ignition switch)
3. Instrument cluster

The restraints control module (RCM) monitors the operation of the safety belt buckles. When the safety belts are buckled and unbuckled, the RCM sends the instrument cluster a status message over the controller area network (CAN). The instrument cluster monitors these messages and operates the chime according to the data. The safety belt warning chime sounds when the driver or passenger safety belt is not fastened and the ignition key is turned from the OFF/LOCK or ACC to the ON or START position. The safety belt warning chime stops sounding when the safety belt is fastened, when the ignition key is turned from the ON or START position to the OFF/LOCK or ACC position, or when the chime has sounded for approximately 6 seconds.

Possible Causes

1. RCM
2. Instrument cluster

The restraints control module (RCM) monitors the operation of the safety belt buckles. When the safety belts are buckled and unbuckled, the RCM sends the instrument cluster a status message over the CAN. The safety 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 once the vehicle speed has exceeded 5 km/h (3 mph).

Possible Causes

1. RCM
2. Instrument cluster

The parking brake warning chime warns that the parking brake is engaged when the vehicle is in motion. The parking brake warning chime sounds if the ignition key is in ON position, the parking brake is engaged, and the vehicle speed is greater than 5 km/h (3 mph). The SJB monitors the parking brake status and when the parking brake is applied or released, the SJB sends the instrument cluster the parking brake status over the CAN. The instrument cluster monitors these messages and operates the chime according to the data.

Possible Causes

1. Brake warning indication
2. Vehicle speed input
3. Instrument cluster