Tests AD: LFC 25/DTC B1871 - Passenger Air Bag Deactivation Switch Fault

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

Normal Operation

The Restraints Control Module (RCM) monitors the status of the Passenger Air Bag Deactivation (PAD) switch at RCM C270 pin 9, circuit 1112 (WH/LB). 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 can be caused by:
- a damaged or inoperative PAD switch.
- a damaged or inoperative RCM.
- a short to battery, short to ground or open on circuit 1112 (WH/LB).