13: Air Bag Circuit Shorted to Ground
DIAGNOSTIC TROUBLE CODE 13 - AIR BAG CIRCUIT SHORTED TO GROUNDNormal Operation
Typical Pin Voltages W/System Connected And Engine Running:
The air bag diagnostic monitor measures the voltage at Pins C1-2, C1-3, C1-4, and C1-5 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 (the expected voltages are shown in the Typical Pin Voltages W/System Connected And Engine Running table). 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 a DTC 13 on the AIR BAG indicator to indicate a possible short to ground on these circuits.
At the same time the air bag diagnostic monitor begins flashing DTC 13, it attempts to disarm the air bag system to prevent inadvertent deployment of the air bag(s) by blowing the 10 A battery fuse feeding air bag diagnostic monitor Pins C2-19 and C2-20. It attempts to blow the fuse by activating a solid state switch which shorts the battery feed at Pin C2-19 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 one minute apart.
- If the air bag diagnostic monitor has blown the fuse and thus removed B+ at Pin C1-14, a DTC 12 will be stored (refer to DTC 12 and 52 for further details).
- If the air bag diagnostic monitor attempts to blow the 10 A battery fuse three times and fails each time, a DTC 24 will be stored (refer to DTC 24 and 64 for further details).
- After the 10 A 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 C1-2, C1-3, C1-4, and C1-5 be intermittent or repaired, the air bag diagnostic monitor will flash a DTC 53 (or a higher priority DTC such as DTC 12 if one exists) on the next ignition switch cycle.
Possible Causes
WARNING: Servicing a DTC 13 will usually occur after servicing of a DTC 12 has been completed. 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 unless the air bag system first has been deactivated (see deactivation procedure for details).
Low voltage at air bag diagnostic monitor Pins C1-2, C1-3, C1-4, or C1-5 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 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 ground within the driver side air bag module or passenger side air bag module.
Electrical Schematic - Diagnostic Trouble Code 13:
Pinpoint Test - 13-1 - 13-5:
Pinpoint Test - 13-6 - 13-7:
