F 250 4WD Pickup V8-4.6L SOHC VIN W (1998)
Standby Power Supply: Description and Operation
The air bag diagnostic monitor includes an internal backup power supply. This feature provides sufficient backup power to deploy the air bag in the
event the battery or battery cables are damaged in a collision before safing and air bag sensors close. The backup power supply will deplete its stored
energy approximately one minute after the battery ground cable is disconnected.