Passenger Air Bag Deactivation Switch harness is open or shorted
Passenger Air Bag Deactivation Switchcircuit poor electrical connection
Faulty Restraints Control Module (RCM)
How to Fix the B1871 Code?
Start by checking the "Possible Causes" listed above. Visually inspect the related wiring harness and connectors. Check for damaged components and look for broken, bent, pushed out, or corroded connector's pins.
The cost to diagnose the B1871 code is 1.0 hour of labor. The auto repair's diagnosis time and labor rates vary by location, vehicle's make and model, and even your engine type. Most auto repair shops charge between $75 and $150 per hour.
The Restraints Control Module (RCM) monitors status of Passenger Air Bag Deactivation (PAD) switch. The PAD switch signals RCM by switching resistance to ground. If RCM senses 900-1100 ohms in PAD switch, it enables passenger-side air bag and turns off PAD switch warning light. If RCM senses 400-600 ohms in PAD switch, it deactivates passenger-side air bag and turns on PAD switch warning light. If RCM senses an invalid resistance, it will store Diagnostic Trouble Code (DTC) B1871 in memory.
B1871 Code - Passenger Air Bag Deactivation Switch Fault
Precautions for SRS “AIR BAG” and “SEAT BELT PRE-TENSIONER” Service
Never probe the electrical connectors on air bag, side air curtain modules or seat belts.
Never disassemble or tamper with safety belt buckle/retractor pretensioners, adaptive load limiting retractors, safety belt inflators, or probe the electrical connectors.
Do not use electrical test equipment to check SRS circuits unless instructed to in this Service Manual.
Before servicing the SRS, turn ignition switch OFF, disconnect both battery cables and wait at least 3 minutes. For approximately 3 minutes after the cables are removed,
it is still possible for the air bag and seat belt pre-tensioner to deploy. Therefore, do not work on any SRS connectors or wires until at least 3 minutes have passed.
Failure to follow this instruction may result in the accidental deployment of these modules, which increases the risk of serious personal injury or death.