Test Notes/Typical Pin Voltages

WARNING:Diagnostic Trouble Code 53 Refer to Diagnostic Trouble Code 13 Servicing a Diagnostic Trouble Code (DTC) 13 will usually occur after servicing of a DTC 12 has been completed. Under no circumstances substitute another fuse value for the 10a 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 10a battery fuse unless the air bag system first has been deactivated






NORMAL OPERATION
Diagnostic Trouble Code 53 Refer to Diagnostic Trouble Code 13 The air bag diagnostic monitor measures the voltage at Pins 2, 3, 4, and 5 of the air bag diagnostic monitor connector. The voltage at these pins is set by the air bag diagnostic monitor and varies with charging system voltage. If the air bag diagnostic monitor detects low voltage on any of these pins, the air bag diagnostic monitor will store in memory and flash out on the air bag indicator a DTC 13 to indicate a possible short to ground on these circuits.

At the same time the air bag diagnostic monitor begins flashing out DTC 13, it attempts to disarm the air bag system to prevent inadvertent deployment of the air bag(s) by blowing the 10A battery fuse feeding air bag diagnostic monitor Pins 13 and 14. It attempts to blow the fuse by activating a solid state switch which shorts the battery feed at Pin 13 to sheet metal ground at the air bag diagnostic monitor's bracket.

The air bag diagnostic monitor will make up to three attempts to blow this fuse, spaced at one minute apart.

- If the air bag diagnostic monitor has blown the fuse and thus removed battery voltage at Pin 14, a DTC 12 will be stored.
- If the air bag diagnostic monitor attempts to blow the 10A battery fuse three times and fails each time, a DTC 24 will be stored.
- After the 10A fuse is blown or three attempts to blow it fail, the air bag diagnostic monitor will not attempt to disarm again until the DTC 13 condition has been serviced and cleared.
- Should the short on Pins 2, 3, or 5 be intermittent or repaired, the air bag diagnostic monitor will flash out a DTC 53 (or a higher priority DTC such as DTC 12 if one exists) on the next ignition switch cycle.

POSSIBLE CAUSES

Low voltage at air bag diagnostic monitor Pins 2, 3, 4, or 5 can be caused by:

- A short to ground on Circuits 607 (LB/O), 614 (GY/O), 615 (GY/W), or 616 (PK/BK) causing the diagnostic voltage to drop.
- Resistance to ground on Circuits 617 (PK/O), 619 (PK/W), 624 (Y/W), 625 (Y/LG) or internal resistance to ground in either of the radiator primary crash sensors may activate an air bag diagnostic monitor circuit which may cause the voltage to drop.
- An internal short to ground within the air bag sliding contact causing the driver side air bag circuit(s) to be shorted to ground.
- An internal short to case ground within the driver side air bag module or passenger side air bag module.