Displaying & Reading Trouble Codes

Features and Functions
The air bag diagnostic monitor illuminates the air bag indicator for approximately six 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 (DTC), 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.

DTC's are displayed as a series of flashes and pauses of the air bag indicator. DTC's 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)...

DTC's are prioritized numerically so that if two or more faults occur at the same time, the DTC 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 Memory (NVM) to store DTC's and retain them indefinitely. The air bag diagnostic monitor will always flash the highest priority DTC stored in NVM. DTC's 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.

- Each DTC number 12-45 represents a hard fault (a fault that is still present). Hard DTC's are higher priority than intermittent diagnostic trouble codes, and may not be cleared from NVM.

- Each of these hard DTC's has an equivalent DTC which is the sum of the DTC number plus 40. This equivalent DTC will indicate that an intermittent condition exists, or that a hard condition has been repaired.

- Only the intermittent (repaired) DTC numbers 52-85, may be cleared from the air bag diagnostic monitor. Example: A DTC 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 Warning 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 DTC 55 or any other DTC. The air bag warning indicator must be serviced before DTC 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 1OA battery fuse.

WARNING: UNDER NO CIRCUMSTANCES SUBSTITUTE ANOTHER FUSE VALUE FOR THE 1OA BATTERY FUSE. ANY FUSE OTHER THAN 10A MAY CAUSE DISARMING FAILURE AND MAY RESULT IN DANGER TO THE OCCUPANTS OF THE VEHICLE. DO NOT ATTEMPT TO REPLACE THE 1OA BATTERY FUSE UNTIL THE AIR BAG SYSTEM FIRST HAS BEEN DEACTIVATED.

If the 1OA 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 unwanted deployment DTC and the loss of deployment power DTC. The loss of deployment power DTC is the highest priority.

Some Diagnostic Trouble Codes (DTCs) for intermittent problems (61-85) may not automatically flash on the air bag indicator and may require retrieval. If an air bag DTC has been reported on a vehicle but is not currently flashing, this may be due to two reasons:

- A charging system concern has been identified by the diagnostic monitor and a DTC 12 indicated. DTC 12 will not be stored in the air bag diagnostic monitor's Non-Volatile Random Access Memory (NVRAM) under these circumstances. Correction of the charging system problem will eliminate the DTC.

- An intermittent fault has occurred and the fault is no longer present. The diagnostic monitor may be programmed to flash "intermittent" DTCs 61-85 that are stored in NVRAM. Use the following procedure to access the stored DTCs.

(1). Locate the air bag diagnostic service connector containing Circuit 631 (T/R). This is a grey connector under the glove compartment.

(2). With the ignition key OFF, short Circuit 631 to the ground contained in the service connector or another good ground.

(3). Turn the ignition key 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. After service, repeat steps 1-4 and clean the DTCs cleared using the DTC Clearing Procedure .