Fire Suppression System: Description and Operation

FIRE SUPPRESSION SYSTEM

WARNING: The fire suppression system backup power supply must be depleted before lifting the vehicle or when repairing or replacing any of the following:
- fire suppression system components
- components located near the fire suppression manual switch
- fuel tank and components located near the fuel tank
- rear axle and components located near the rear axle

To deplete the backup power supply, disconnect the battery and wait at least 1 minute. Be sure to disconnect the auxiliary batteries and power supplies (if equipped). Failure to follow these instructions may result in personal injury.

The fire suppression system is designed to help reduce the risk of fire in high speed rear impacts. The fire suppression system deploys chemicals designed to suppress the spread of fire or potentially extinguish a fire, thereby providing more time for occupants to escape from a crashed vehicle.

The fire suppression system can be activated:
- automatically when a high speed, high energy rear impact has occurred.
- manually when other situation require fire suppression.

In the event of a fire suppression system manual deployment, the fire suppressor manifold nozzles will deploy to near ground level and the underbody of the vehicle will be covered with suppressant fluid.

CAUTION: The fire suppression manifold nozzles may need to be secured in the up position before driving the vehicle through an automatic car wash.

The suppressant contains no hazardous materials (but may cause minor skin or eye irritation) and can be readily cleaned up by flushing the vehicle underbody with water, or soap and water. Manual deployment should have no effect on vehicle handling.

The fire suppression system consists of the following components:
- fire suppression module (FSM)
- fire suppression manual switch
- fire suppressors
- fire suppression manifolds
- fire suppression system indicator (part of the instrument cluster)

NOTE: These components must be replaced with new components in the event of a fire suppression system manual deployment. A new fire suppression manual switch must be installed only if the switch cover was damaged during the manual activation.

Fire Suppression Module (FSM)

WARNING: The fire suppression module (FSM) orientation is critical for correct system operation. If a vehicle equipped with a fire suppression system has been involved in a collision in which the rear floor panel area has been damaged, inspect the mounting bracket for damage. If the mounting bracket is damaged, a new FSM must be installed whether or not the fire suppressors have deployed. In addition, make sure the area of the FSM mounting area is restored to its original condition.

The fire suppression module (FSM) is mounted underneath the rear seat cushion. The FSM performs the following functions:
- signals the suppressors to deploy the suppressant material in the event of a deployable crash.
- monitors the fire suppression system for faults.
- illuminates the fire suppression system indicator if a fault is detected.
- receives information from the anti-lock brake system (ABS) module.
- communicates through the data link connector (DLC) the current or historical diagnostic trouble codes (DTCs).

The FSM monitors the fire suppression system for possible faults. If a fault is detected while the ignition switch is in the ON position, the FSM will illuminate the fire suppression system indicator located in the instrument cluster.

When the ignition switch is cycled (turned off and then on), the fire suppression system indicator remains lit for six seconds and then goes out. If a fire suppression fault exists, the fire suppression system indicator flashes or remains lit. The FSM communicates the current and historical DTCs through the DLC, using the diagnostic tool.

The FSM includes a backup power supply. This feature provides sufficient backup power to deploy the suppressors in the event that the ignition circuit is damaged in a collision before suppressors deployment is initiated. The backup power supply will deplete its stored energy approximately one minute after the power is removed from the FSM.

Fire Suppression Manual Switch
The fire suppression manual switch allows for manual deployment of the suppressors in the event of a fire, when the system has not deployed automatically. Manual activation is possible only when the ignition lock cylinder is in the ON position.

The fire suppression manual switch is located in a console on the headliner between the sun visors.

Fire Suppressors

WARNING: To reduce the risk of accidental deployment, never probe the connectors on the fire suppressors. Failure to follow this instruction may result in personal injury.

The fire suppressors deploy upon receiving voltage from the fire suppression module (FSM).

The fire suppressors are mounted above the rear axle on the number 4 crossmember.

Fire Suppression Manifolds
The fire suppression manifolds spread the fire suppressant material under the vehicle and around the fuel tank in an event of fire suppression system deployment.

The fire suppression manifolds are mounted on the fire suppressors.

Electrical System
The electrical system that supports the fire suppression system:
- is powered by the battery through the ignition circuit.
- provides the electrical path from the fire suppression module (FSM) to the fire suppressors.
- provides the electrical path from the fire suppression manual switch to the FSM.
- provides the electrical path from the FSM to the fire suppression system indicator.
- provides the electrical path from the FSM to the DLC.
- provides the electrical path from the FSM to the powertrain control module (PCM).