Displaying & Reading Trouble Codes
RETRIEVING LAMP FLASH CODES
- The air bag diagnostic monitor illuminates the AIR BAG indicator for approximately 6 seconds when the ignition switch is turned to RUN and then turns the air bag indicator OFF. This indicates that the AIR BAG indicator is operational. If the AIR BAG indicator does not illuminate at all, stays on continuously, or flashes at any time, then a fault has been detected by the air bag diagnostic monitor.
- Diagnostic Trouble Codes (DTCs), if present, will begin flashing within 30 seconds after the ignition switch has been turned to RUN. This is the amount of time it takes the air bag diagnostic monitor to perform all tests and verify system faults, if present.
- Diagnostic trouble codes are displayed as a series of flashes and pauses of the AIR BAG indicator. Diagnostic trouble codes are two-digit numbers. Example: A DTC 32 is displayed as follows:
Flash flash flash - (two second pause) - flash flash - (five second pause)...
Flash flash flash - (two second pause) - flash flash - (five second pause)...
- Diagnostic trouble codes are prioritized numerically so that if two or more faults occur at the same time, the diagnostic trouble code with the highest priority will be displayed.
- After the DTC is displayed five times, the AIR BAG indicator will illuminate continuously until the ignition switch is cycled.
- The air bag diagnostic monitor incorporates Non Volatile Random Access Memory (NVRAM) to store diagnostic trouble codes and retain them indefinitely. The air bag diagnostic monitor will always flash the highest priority diagnostic trouble code stored in NVRAM. Diagnostic trouble codes may be cleared from the air bag diagnostic monitor after the fault conditions are serviced.
- The air bag diagnostic monitor distinguishes between hard and intermittent (or repaired) fault conditions.
Diagnostic Trouble Code Table:
- Each diagnostic trouble code number 12 through 45 represents a hard fault (a fault that is still present). Hard diagnostic trouble codes are higher priority than intermittent diagnostic trouble codes, and may not be cleared from NVRAM.
- Each of these hard diagnostic trouble codes has an equivalent diagnostic trouble code which is the sum of the diagnostic trouble code number plus 40. This equivalent diagnostic trouble code will indicate that an intermittent condition exists, or that a hard condition has been repaired.
- Only the intermittent (repaired) diagnostic trouble codes, numbers 52 through 85, may be cleared from the air bag diagnostic monitor. Example: A Diagnostic Trouble Code 32 indicates that high resistance in the driver side air bag circuit has been, and still is, present. A DTC 72 (32 + 40) indicates that high resistance in the driver side air bag circuit existed at one time, but no longer exists due to an intermittent condition or a repair made to the circuit.
- If a system fault exists and the AIR BAG indicator is not functioning, an audible tone will be heard indicating a need for service. The tone is a series of five sets of five beeps. This DOES NOT indicate a diagnostic trouble code 55 or any other diagnostic trouble code. The AIR BAG indicator must be serviced before diagnostic trouble codes can be determined.
- If a fault exists that makes unwanted air bag deployment possible, the air bag diagnostic monitor will attempt to remove deployment power by turning on a solid state switch to blow the 10 A battery fuse.
WARNING: Under no circumstances substitute another fuse value for the 10 A battery fuse. Any fuse other than 10 A may cause disarming failure and may result in danger to the occupants of the vehicle. Do not attempt to replace the 10 A battery fuse until the air bag system first has been deactivated.
- If the 10 A battery fuse has successfully been blown by the air bag diagnostic monitor, the air bag diagnostic monitor will not attempt to blow it again until the proper fault has been serviced and cleared. The air bag diagnostic monitor will store both the diagnostic trouble code that caused it to blow the 10 A battery fuse and the loss of deployment power Diagnostic Trouble Code (DTC) 12. The loss of deployment power diagnostic trouble code is the highest priority.
- The air bag diagnostic monitor includes an internal backup power supply. This feature provides sufficient backup power to deploy the air bags in the event that the battery or battery cables are damaged in a collision before the crash sensors are activated. The backup power supply will deplete its stored energy approximately one minute after the negative battery cable is disconnected.
DIAGNOSTIC TROUBLE CODE RETRIEVAL
Trouble Codes for intermittent concerns (DTCs 61 through 85) will not automatically flash on the AIR BAG indicator and requires retrieval. If an air bag DTC has been reported on a vehicle but is not currently flashing, this is due to an intermittent fault and this fault is no longer present. The diagnostic monitor is not programmed to flash "intermittent" DTC's 61 through 85 that are stored in NVRAM. Use the following procedure to access the stored DTC(s).
1. Locate the air bag diagnostic service connector containing Circuit 631 (T/R). This is a gray connector behind the glove compartment.
2. With the ignition switch OFF, short Circuit 631 (T/R) to the ground contained in the service connector or another good ground.
3. Turn the ignition switch to RUN and observe the six second AIR BAG indicator prove out.
4. Within two seconds after indicator prove out, remove the short on Circuit 631.
5. Stored DTCs will be displayed. Refer to the Diagnostic Trouble Code Table for the DTC displayed. Diagnostic Trouble Code Priority Index