Test N: LFC 14/DTC B1901 - External Crash Sensor Shorted to GND

N1:

N2:

N3 - N5:

Normal Operation
The external crash sensor monitors the severity of a crash event. If the crash event is severe enough, the sensor will close and signal the Restraints Control Module (RCM) to deploy the air bags. The external crash sensor contains a 787 ohm resistor.

The RCM measures this resistance to verify that the crash sensor is correctly mounted and connected. If there is a short to ground on circuit 619 (PK/WH), the RCM will store a Diagnostic Trouble Code (DTC) B1901 in memory and flash a Lamp Fault Code (LFC) 14 (or higher priority code if one exists) on the air bag indicator.

Possible Causes
An external crash sensor shorted to ground fault could be caused by:
^ a short to ground on circuit 619 (PK/WH).
^ a damaged or inoperative external crash sensor.