Test D: LFC 25/DTC B1871 - Passenger Air Bag Deactivation (PAD) Switch Fault

PINPOINT TEST D: LFC 25/DTC B1871 - PASSENGER AIR BAG DEACTIVATION (PAD) SWITCH FAULT

D1-D3:

D3-D5:

D5-D7:

D8:

Normal Operation
The restraints control module (RCM) monitors the status of the passenger air bag deactivation (PAD) switch at C310a pin 8, circuit 8-JA26 (WH/BK). The PAD switch signals the RCM by switching a resistance to ground. If the RCM senses 900-1,100 ohms in the PAD switch, it enables the passenger air bag and turns off the PAD switch warning lamp. If the RCM senses 400-600 ohms in the PAD switch, it deactivates the passenger air bag and turns the PAD switch warning lamp on. If the RCM detects an invalid resistance, it will store a diagnostic trouble code (DTC) B1871 in memory and flash a lamp fault code (LFC) 25 (or higher priority code if one exists) on the air bag indicator.

Possible Causes
A PAD switch fault could be caused by:
- a damaged or inoperative PAD switch.
- a faulted RCM.
- a short to battery, short to ground or open on circuit 8-JA26 (WH/BK).
- a open on circuit 31-JA26 (BK/RD).