Test Notes

NORMAL OPERATION

NOTE: Diagnostic Trouble Code (DTC) 14 will flash only while the short to ground is present.

The air bag diagnostic monitor measures the voltage at Pins C277-2, Circuit 624 (Y/W) and C277-6, Circuit 625 (Y/LG) of the air bag diagnostic monitor connector. The normal voltage at these pins is approximately 10 volts (± 1 volt) when the ignition switch is in RUN, or battery positive voltage (B+) when the ignition switch is OFF. If the air bag diagnostic monitor detects that the voltage at Pins C277-2 or C277-6 has dropped to 5 volts or less, the air bag diagnostic monitor will flash Code 14 on the air bag indicator to indicate a short to ground on any of these circuits; refer to Possible Causes for additional circuits that may be shorted to ground. When flashing DTC 14, the air bag diagnostic monitor opens its internal thermal fuse. This disables the air bag deployment circuit. If the voltage at Pins C277-2 and C277-6 returns to normal, a DTC 51 will be present due to the open thermal fuse; refer to DTC 51 : Air Bag Diagnostic Monitor Internal Thermal Fuse Blown for additional information.

POSSIBLE CAUSES

NOTE: The gray diagnostic monitor harness connector contains a shorting bar inside the connector that will short Pins C277-2 and C277-3 together whenever the air bag diagnostic monitor is disconnected. Since Pin C277-3 is ground, shorting Pin C277-2 to Pin C277-3 will cause a short to ground on both Pins C277-2 and C277-17. Make sure to remove the plastic locking wedge from the gray harness connector before checking resistance of these circuits to ground.

A drop in voltage at air bag diagnostic monitor Pins C277-2 and C277-6 can be caused by:
1. A short to ground within the wiring harness on Circuits 624 (Y/W), 625 (Y/LG), 617 (PK/O) or 619 (PK/W), causing the diagnostic voltage to drop.
2. An internal short to case ground within either of the primary crash sensors.