B2871 Ford Code - Left Rear Tire Pressure Sensor Fault
Quick Answer
The Tire Pressure Monitor (TPM) system monitors the air pressure in the 4 road tires with wheel-mounted tire pressure sensors. Common causes include Low tire pressure, Tire pressure sensor is missing or damaged, Spare tire is installed as a road wheel. 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
- B2871 Ford indicates Left Rear Tire Pressure Sensor Fault.
- Common causes
- Common causes include Low tire pressure, Tire pressure sensor is missing or damaged, Spare tire is installed as a road wheel.
- 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 B2871 Ford Description
Each tire pressure sensor transmission is compared against a low-pressure limit (pressure listed on vehicle certification label minus 25 percent, which will be about 6-9 psi). If it is determined that the tire pressure has fallen below this limit, the SJB sends a message to the instrument cluster, which then illuminates the low pressure warning indicator and displays the appropriate message(s) in the message center (if equipped).
What are the Possible Causes of the DTC B2871 Ford?
- Low tire pressure
- Tire pressure sensor is missing or damaged
- Spare tire is installed as a road wheel
- Incorrect tire pressure sensor is installed
- Tire pressure sensor installed incorrectly
- Faulty Left Rear Tire Pressure Sensor
How to Fix the DTC B2871 Ford?
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.
Code Tech Notes
What is the Cost to Diagnose the Code?
Labor: 1.0
To diagnose the B2871 Ford 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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Frequently Asked Questions about B2871 Ford Code
1. What does the OBDII code B2871 mean on a Ford vehicle?
The code B2871 indicates a fault with the left rear tire pressure sensor, which means the vehicle is unable to receive accurate tire pressure data from that sensor.
2. What are the common symptoms of the B2871 code?
Symptoms include a TPMS warning light on the dashboard, inaccurate tire pressure readings, or no reading for the left rear tire.
3. What causes the B2871 code to trigger?
Common causes include a damaged or malfunctioning tire pressure sensor, a dead sensor battery, or interference with the TPMS signal.
4. Can I continue driving with the B2871 code?
Yes, but it is not recommended as you may not receive accurate tire pressure warnings, which could lead to unsafe driving conditions if the tire is underinflated or overinflated.
5. How do I diagnose the B2871 code?
Use a TPMS scan tool to check the status of the left rear tire pressure sensor. Inspect the sensor for physical damage and verify its signal strength and battery life.
6. How can I fix the B2871 code on my Ford?
Replace the faulty left rear tire pressure sensor if it’s damaged or has a dead battery. Relearn or program the new sensor using a TPMS tool after replacement.
7. How much does it cost to fix a B2871 code?
Replacing a tire pressure sensor typically costs between $50 and $150 per sensor, plus labor charges if done by a professional.
8. Can low tire pressure cause the B2871 code?
Low tire pressure itself won’t cause the code, but if the sensor is faulty, it may fail to detect and report low pressure properly.
9. Do I need to relearn the TPMS after fixing the B2871 code?
Yes, after replacing the sensor, the TPMS system must be recalibrated or relearned to recognize the new sensor.
10. Can a B2871 code be caused by a software issue?
While rare, a TPMS module software glitch or outdated firmware could potentially cause communication errors. Updating the module software may help in such cases.
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