B1871 Mercury Code - Passenger Air Bag Deactivation Switch Fault
Quick Answer
The Restraints Control Module (RCM) monitors status of Passenger Air Bag Deactivation (PAD) switch. Common causes include Faulty Passenger Air Bag Deactivation Switch, Passenger Air Bag Deactivation Switch harness is open or shorted, Passenger Air Bag Deactivation Switchcircuit poor electrical connection. Severity is High - diagnose this code as soon as possible. Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.
- What it means
- B1871 Mercury indicates Passenger Air Bag Deactivation Switch Fault.
- Common causes
- Common causes include Faulty Passenger Air Bag Deactivation Switch, Passenger Air Bag Deactivation Switch harness is open or shorted, Passenger Air Bag Deactivation Switchcircuit poor electrical connection.
- Severity
- High - diagnose this code as soon as possible.
- Can I drive?
- Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.
Code B1871 Mercury Description
What are the Possible Causes of the DTC B1871 Mercury?
- Faulty Passenger Air Bag Deactivation Switch
- 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 DTC B1871 Mercury?
Review the 'Possible Causes' above and visually examine the corresponding wiring harness and connectors. Check for damaged components and inspect connector pins for signs of being broken, bent, pushed out, or corroded.
What is the Cost to Diagnose the Code?
Labor: 1.0
To diagnose the B1871 Mercury code, it typically requires 1.0 hour of labor. Rates vary by location, vehicle, and shop. Many shops charge between $80–$150 per hour; dealerships and metro areas may be higher, independents may be lower.
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Get the B1871 Mercury code diagnosed by a professional: Find a repair shop in your area
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.
Frequently Asked Questions about B1871 Mercury Code
1. What does OBDII code B1871 mean for a Mercury vehicle?
Code B1871 indicates a fault in the Passenger Air Bag Deactivation (PAD) Switch circuit, meaning the vehicle's system has detected an issue with the switch or its wiring.
2. What are the common symptoms of code B1871 in a Mercury?
Typical symptoms include the airbag warning light illuminating, the passenger airbag not deactivating when the switch is used, or intermittent operation of the deactivation switch.
3. What causes code B1871 in a Mercury?
Common causes include a faulty PAD switch, damaged wiring or connectors in the PAD circuit, or a malfunction in the airbag control module.
4. Can I still drive my Mercury with code B1871 active?
While the vehicle may still be drivable, the airbag system's functionality could be compromised, which poses a safety risk. It’s best to address the issue promptly.
5. How is code B1871 diagnosed in a Mercury?
A technician will use an OBDII scanner to confirm the code, inspect the PAD switch and its wiring, and test the circuit for continuity or short circuits.
6. How do you fix code B1871 in a Mercury?
Repairs may involve replacing the PAD switch, repairing or replacing damaged wiring, or reprogramming or replacing the airbag control module.
7. How much does it cost to repair code B1871 in a Mercury?
Repair costs vary depending on the issue but typically range from $100 to $400, including parts and labor.
8. Can I reset the B1871 code without fixing the issue?
Clearing the code without resolving the underlying fault may temporarily turn off the warning light, but the issue will likely return and could compromise safety systems.
9. Does a faulty PAD switch always trigger code B1871?
Not necessarily. Other issues, such as wiring problems or a malfunctioning airbag module, can also cause this code.
10. Can I fix code B1871 on my Mercury myself?
If you have experience with automotive electrical systems, you may be able to check the switch and wiring. However, due to the safety-critical nature of airbag systems, professional diagnosis and repair are recommended.
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