AutoCodes – Generic – B3666

B3666 Code - Rear Tonneau Position Error

Quick Answer

The Folding Top Control (FTC) Module supplies accessory voltage to the folding top cover open limit switch. Common causes include Faulty Folding Top Cover Latch Actuator, Faulty Folding Top Cover Open Limit Switch, Faulty Folding Top Control (FTC) Module. 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: B3666 indicates Rear Tonneau Position Error.
Common causes: Common causes include Faulty Folding Top Cover Latch Actuator, Faulty Folding Top Cover Open Limit Switch, Faulty Folding Top Control (FTC) Module.
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 1,016

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 10, 2020

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code B3666 Description

The Folding Top Control (FTC) Module supplies accessory voltage to the folding top cover open limit switch. It monitors the signal circuit of this switch to determine the open and closed position of the folding top cover. At the same time the Body Control Module (BCM) supplies battery voltage to the folding top cover latch ajar switch and monitors this circuit to determine if the folding top cover is latched or unlatched. The BCM communicates the status of the folding top cover latch ajar switch via class 2 message to the FTC module. Diagnostic Trouble Code (DTC) B3666 will set as a current DTC, if the FTC module senses that the folding top cover latch is not ajar while the folding top cover open limit switch is active.

OBDII Code B3666 - Rear Tonneau Position Error - AutoCodes.com — B3666 Code - Rear Tonneau Position Error

What does this mean?

What are the Possible Causes of the DTC B3666?

Faulty Folding Top Cover Latch Actuator
Faulty Folding Top Cover Open Limit Switch
Faulty Folding Top Control (FTC) Module
Faulty Body Control Module (BCM)

How to Fix the DTC B3666?

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 B3666 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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Need Help with the Code?

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Information for Specific Makes

B3666 Chevrolet — Rear Tonneau Position Error

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 B3666 Code

1. What does OBDII code B3666 mean?

Code B3666 indicates a "Rear Tonneau Position Error," which means there is an issue with the rear tonneau cover's position sensor or its operation.

2. What are the symptoms of code B3666?

Common symptoms include the tonneau cover not opening or closing properly, unusual noises during operation, or a warning light/message on the dashboard.

3. What causes the B3666 code to trigger?

The code can be caused by a faulty position sensor, wiring issues, a malfunctioning tonneau cover motor, or mechanical obstructions in the tonneau cover mechanism.

4. Can I still drive my car with the B3666 code?

Yes, you can typically drive the car, but the tonneau cover may not function correctly, which could affect cargo security or vehicle aerodynamics in some cases.

5. How do I diagnose the B3666 code?

Start by scanning the vehicle with an OBDII tool, inspecting the tonneau position sensor and associated wiring, and checking for mechanical obstructions or damage.

6. What repairs are needed to fix code B3666?

Repairs may include replacing the position sensor, repairing damaged wiring or connectors, or realigning or repairing the tonneau cover mechanism.

7. How much does it cost to fix the B3666 code?

Repair costs vary but can range from $100â€“$500, depending on whether the issue is with the sensor, wiring, or the tonneau cover mechanism itself.

8. Can I reset the B3666 code without repairs?

You can clear the code using an OBDII scanner, but it will likely return if the underlying issue isnâ€™t resolved.

9. What tools are needed to troubleshoot the B3666 code?

You may need an OBDII scanner, a multimeter for electrical testing, and basic hand tools for inspecting and repairing the tonneau cover system.

10. Is the B3666 code specific to certain vehicles?

Yes, this code typically applies to vehicles equipped with a motorized rear tonneau cover, commonly found in trucks or SUVs with a powered cargo cover system.