Diagnostic Trouble Code Clearing

The air bag diagnostic monitor continually checks the air bag system for readiness. When a fault condition is detected, the DTC associated with that fault is stored in the air bag diagnostic monitor's Non Volatile Random Access Memory (NVRAM). After writing the DTC to NVRAM, the air bag diagnostic monitor signals the fault by flashing the appropriate diagnostic trouble code on the AIR BAG indicator.

The diagnostic trouble code written to NVRAM is permanently stored in the air bag diagnostic monitor until cleared by the diagnostic trouble code clearing procedure.
- Upon each cycle of the ignition switch, the air bag diagnostic monitor checks for diagnostic trouble codes written in NVRAM. If any diagnostic trouble codes exist in NVRAM, the air bag diagnostic monitor will then check to see if these fault conditions are still present.
- If the conditions of the diagnostic trouble code in NVRAM are still present, then the air bag diagnostic monitor will use the AIR BAG indicator to flash the diagnostic trouble code number that was written in memory.
- If the conditions of the diagnostic trouble code are not still present (indicating an intermittent or serviced fault), the air bag diagnostic monitor will use the AIR BAG indicator to flash a DTC which is the sum of the diagnostic trouble code in NVRAM plus 40.

DTCs 52, 53, and 54 will automatically flash on the AIR BAG indicator if DTCs 12, 13, or 14 have been repaired or are intermittent and not currently present. All other intermittent or repaired DTCs (61 through 85) will only be flashed on the AIR BAG indicator when the Diagnostic Trouble Code Retrieval procedure is performed. Displaying & Reading Trouble Codes

Example: Due to corrosion, high resistance develops on the driver side air bag circuit. The air bag diagnostic monitor stores a diagnostic trouble code 32 in NVRAM. Upon each cycle of the ignition switch, the air bag diagnostic monitor checks the resistance of the driver air bag circuit.
- If the resistance is still high, the air bag diagnostic monitor causes the air bag indicator to flash a DTC 32.
- If the resistance falls within the normal range due to service or an intermittent condition, the air bag diagnostic monitor causes DTC 72 to be flashed on the AIR BAG indicator when the Diagnostic Trouble Code Retrieval procedure is followed.

Once a fault has been serviced, the associated diagnostic trouble code may be cleared from NVRAM. Only diagnostic trouble codes that the air bag diagnostic monitor sees as repaired or intermittent may be cleared (diagnostic trouble codes 52 and above). Under no circumstances can hard fault conditions (diagnostic trouble codes 45 and below) be cleared.

1. Follow the diagnostic procedures to service the fault condition flashing on the AIR BAG indicator.
2. Cycle the ignition switch OFF and then to RUN.
3. Observe AIR BAG indicator prove out (6 ± 2 seconds) followed by diagnostic trouble code (52 through 54) flashing completely one time.
4. Follow Diagnostic Trouble Code Retrieval procedure to have stored DTCs (61 through 85) flashed on the AIR BAG indicator.










5. Locate the Diagnostic "Trouble Code Clear" Connector located behind the glove compartment containing Circuits 631 (T/R) and 57 (BK).
6. Use a jumper wire to short Circuit 631 (T/R) to Circuit 57 (BK) or to another good ground. This short must be made after the diagnostic trouble code flashes completely one time, but before the warning light stays on continuously.
7. Hold short until air bag diagnostic monitor tone sounds (approximately five seconds).
8. Release short on Circuit 631 (T/R) to Circuit 57 (BK). This short must be released within 25 seconds after the diagnostic monitor tone sounds.

Diagnostic trouble code is now cleared from NVRAM.

Next highest priority diagnostic trouble code stored in NVRAM (if one exists) can be retrieved by following the Diagnostic Trouble Code Retrieval procedure. Repeat steps 3-8 as necessary to clear all stored DTCs.