AutoCodes – Generic – B3971

B3971 Code - Folding Top Position Sensor

Quick Answer

The Folding Top Control (FTC) Module supplies accessory voltage to the top open and closed limit switches. Common causes include Faulty Folding Top Position Sensor, Folding Top Position Sensor harness is open or shorted, Folding Top Position Sensor circuit 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: B3971 indicates Folding Top Position Sensor.
Common causes: Common causes include Faulty Folding Top Position Sensor, Folding Top Position Sensor harness is open or shorted, Folding Top Position Sensor circuit 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.

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Code Popularity 782

How popular is this code, among other codes? Low

Repair Importance Level

Urgent (Diagnose now) (3 / 3)

Repair Difficulty Level

Advanced (Pro) (3 / 3)

What is this?

Table of contents Created and updated by William Orellana on Mar 25, 2020

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code B3971 Description

The Folding Top Control (FTC) Module supplies accessory voltage to the top open and closed limit switches. It monitors the signal circuits of these switches to determine the open and closed position of the top. When the top is in the closed position the following definitions of the limit switches should be true: Top Closed Switch-The switch will be closed to voltage and the scan tool parameter should display Active and Top Open Switch-The switch will be open and the scan tool parameter should display Inactive. The FTC module will set B3971 as a current Diagnostic Trouble Code (DTC) if it senses that both the top open and top closed limit switches are active at the same time.

OBDII Code B3971 - Folding Top Position Sensor - AutoCodes.com — B3971 Code - Folding Top Position Sensor

What does this mean?

What are the Possible Causes of the DTC B3971?

Faulty Folding Top Position Sensor
Folding Top Position Sensor harness is open or shorted
Folding Top Position Sensor circuit poor electrical connection
Faulty Folding Top Control (FTC) Module

How to Fix the DTC B3971?

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 B3971 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.

Need more information about the B3971 code?

Need more information on how to fix the B3971 code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the B3971 code diagnosed by a professional: Find a repair shop in your area

Information for Specific Makes

B3971 Buick — Folding Top Position Sensor
B3971 Cadillac — Folding Top Position Sensor
B3971 Chevrolet — Folding Top Position Sensor
B3971 GMC — Folding Top Position Sensor

About the author: William Orellana is a Master Mechanic and Mechanical Engineer with over 30 years of experience diagnosing and repairing vehicles. Learn more about his background.

Frequently Asked Questions about B3971 Code

1. What are the common symptoms of OBDII code B3971 (Folding Top Position Sensor)?

- Common symptoms include the convertible top not operating correctly, failure to fully open or close, or erratic movement.

2. What causes OBDII code B3971 to trigger?

- This code is typically triggered by a fault in the folding top position sensor or related wiring.

3. How can I diagnose the issue related to OBDII code B3971?

- You can use a scan tool to read the code and inspect the folding top position sensor and its wiring for any visible damage or issues.

4. Can a malfunctioning folding top position sensor be repaired, or does it need to be replaced?

- In most cases, a malfunctioning folding top position sensor will need to be replaced to resolve the issue.

5. Are there any quick tips for fixing OBDII code B3971 at home?

- Quick tips include checking the sensor's wiring for any loose connections or damage and ensuring the sensor is properly aligned and secured.

6. Can I continue driving my vehicle with OBDII code B3971 present?

- It is not recommended to continue driving the vehicle with this code present, as it may lead to further damage or safety issues with the convertible top mechanism.

7. How much does it cost to repair the folding top position sensor related to OBDII code B3971?

- The cost of repairing or replacing the folding top position sensor can vary depending on the make and model of the vehicle and the labor rates at the repair shop.

8. Is it possible to reset OBDII code B3971 without fixing the underlying issue?

- While you can clear the code with a scan tool, it is not recommended to ignore the underlying issue, as it may result in continued problems with the convertible top.

9. Are there any preventive measures to avoid OBDII code B3971 in the future?

- Regularly inspecting and maintaining the convertible top mechanism, including the folding top position sensor, can help prevent issues that trigger this code.

10. Can a DIY enthusiast with basic automotive knowledge fix OBDII code B3971?

- Depending on your experience and access to tools, it may be possible to replace the folding top position sensor yourself, but it's recommended to consult a professional if unsure.