Procedures
Fire Suppression System Depowering and Repowering
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 all auxiliary batteries and power supplies (if equipped). Failure to follow these instructions may result in serious personal injury.
WARNING: Always wear eye protection when servicing a vehicle. Failure to follow this instruction may result in serious personal injury.
WARNING: To reduce the risk of accidental deployment, do not use any memory saver devices when depowering the fire suppression system. Failure to follow this instruction may result in serious personal injury.
WARNING: If the vehicle is equipped with a fire suppression system, disconnect the battery before anyone gets under the vehicle or near the rear axle area. You could unintentionally deploy the fire suppression system. Failure to follow these instructions may result in serious personal injury.
NOTE: If a vehicle equipped with a fire suppression system is positioned on a hoist, the fire suppression system must be depowered.
NOTE: The fire suppression system indicator illuminates when the Fire Suppression System Module (FSSM) fuse is removed and the ignition switch is ON. This is normal operation and does not indicate a fire suppression system fault.
NOTE: The fire suppression system must be fully operational and free of faults before releasing the vehicle to the customer.
Depowering procedure
1. Turn all vehicle accessories off.
2. Turn the ignition lock cylinder to the OFF position.
3. Remove the Central Junction Box (CJB) fuse 33 (10A). For additional information, refer to Wiring Diagram Set 96, Police Option for schematic and connector information. Diagrams By Number
4. Turn the ignition lock cylinder to the ON position and visually monitor the fire suppression system indicator for at least 30 seconds. The fire suppression system indicator will remain lit continuously (no flashing) if the correct FSSM fuse has been removed. If the fire suppression system indicator does not remain lit continuously, remove the correct FSSM fuse before proceeding to the next step.
5. Turn the ignition lock cylinder to the OFF position.
6. NOTE: If battery voltage is required for diagnostic procedures, the battery must be connected without installing the FSSM fuse.
Disconnect the battery and any auxiliary batteries and power supplies (if equipped) and wait at least one minute. For additional information, refer to Battery, Mounting and Cables Battery Disconnect.
Repowering procedure
7. Install the CJB fuse 33 (10A) to the CJB and close the cover.
8. NOTE: This step is not required if the battery was connected after the depowering procedure was carried out.
Connect the battery. For additional information, refer to Battery, Mounting and Cables Battery Disconnect.
9. Prove out the fire suppression system as follows:
Turn the ignition lock cylinder from the OFF to the ON position and visually monitor the fire suppression system indicator. The fire suppression system indicator will light continuously for approximately 6 seconds and then turn off. If a fire suppression system fault is present, the fire suppression system indicator will:
- fail to light.
- remain lit continuously.
- flash.
The flashing might not occur until approximately 30 seconds after the ignition lock cylinder has been turned from the OFF to the ON position. This is the time required for the FSSM to complete the testing of the fire suppression system. If this occurs, the fire suppression system fault discovered must be diagnosed and repaired.
Clear all continuous DTCs from the FSSM using a scan tool.