Early Production

Several important features of the air bag diagnostic monitor and its functions within the system are described below. it is necessary that you understand these key features and functions. They will enable you to better understand and perform more efficient air bag system diagnostics.

- The diagnostic monitor illuminates the air bag indicator for approximately six seconds when the Ignition switch is turned to the ON position and then turns it off. This indicates that the air bag indicator is operational. If the air bag indicator does not illuminate or if the lamp stays on or flashes at any time, a fault has been detected by the diagnostic monitor.
- Fault codes are displayed after the initial illumination of the air bag indicator for six seconds. This is the amount of time it takes the monitor to perform all tests and verify system faults, if present.
- Fault codes are displayed as a series of flashes and pauses of the air bag indicator. Each diagnostic trouble code, or series of flashes represents a number. For example, a Diagnostic Trouble Code 3 is displayed as follows:
Flash flash flash - (one second pause) - flash flash flash - etc.
- If a system fault exists AND the indicator is malfunctioning, an audible tone will be heard indicating the need for service. The tone is a series of five sets of five beeps. This DOES NOT indicate a Diagnostic Trouble Code 5. It means that the indicator lamp is out and a system fault exists that requires service.
- If a fault exists that makes unwanted air bag deployment possible, the air bag diagnostic monitor has an internal thermal fuse that will blow automatically. This removes all power to the air bag deployment circuit. The air bag indicator will flash the appropriate code to indicate the suspect circuit.

NOTE: The internal thermal fuse is controlled by the diagnostic monitor. The diagnostic monitor will blow the thermal fuse whenever a short on the deployment circuits occurs (the fuse is not serviceable). The thermal fuse does not blow because of excessive current flowing through It. DO NOT attempt to jumper out the thermal fuse with a circuit breaker or any other type of fuse.

- Fault codes are prioritized so that if two or more different faults occur at the same time, the fault having the highest priority will be displayed first. The highest priority fault will be displayed until it is corrected. After it has been corrected, the next highest priority fault will be displayed.
- The early production air bag system includes a back-up power supply. This feature provides sufficient back up power to deploy the air bags in the event that the battery or battery cables are damaged in a collision before the crash sensors close. The back-up power supply will deplete its stored energy approximately twenty minutes after the positive battery cable is disconnected.

WARNING: THE BACK-UP POWER SUPPLY ENERGY MUST BE DEPLETED BEFORE ANY AIR BAG COMPONENT SERVICE IS PERFORMED. TO DEPLETE BACK UP POWER SUPPLY ENERGY, DISCONNECT THE POSITIVE BATTERY CABLE AND WAIT TWENTY MINUTES OR LOCATE AND DISCONNECT THE BACK-UP POWER SUPPLY FROM THE HARNESS CONNECTOR.