AutoCodes – Mercury – B1D21 Mercury

B1D21 Mercury Code - Remote Control Switch Signal Compare Failure

Quick Answer

The Body Control Module (BCM) monitors the Remote Control Switch. Common causes include Faulty Remote Control Switch, Remote Control Switch harness is open or shorted, Remote Control Switch 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: B1D21 Mercury indicates Remote Control Switch Signal Compare Failure.
Common causes: Common causes include Faulty Remote Control Switch, Remote Control Switch harness is open or shorted, Remote Control Switch 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 839

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 Aug 27, 2019

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code B1D21 Mercury Description

The Body Control Module (BCM) monitors the Remote Control Switch. The BCM sets the OBDII code when the Remote Control Switch is not to factory specifications.

OBDII Code B1D21 Mercury - Remote Control Switch Signal Compare Failure - AutoCodes.com — B1D21 Mercury Code - Remote Control Switch Signal Compare Failure

What does this mean?

What are the Possible Causes of the DTC B1D21 Mercury?

Faulty Remote Control Switch
Remote Control Switch harness is open or shorted
Remote Control Switch circuit poor electrical connection
Faulty Body Control Module (BCM)

How to Fix the DTC B1D21 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 B1D21 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 B1D21 Mercury code diagnosed by a professional: Find a repair shop in your area

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 B1D21 Mercury Code

1. What are the common symptoms of OBDII code B1D21 Mercury Remote Control Switch Signal Compare Failure?

The common symptoms include issues with the remote control functions, such as the inability to lock or unlock the doors remotely.

2. What are the possible causes of OBDII code B1D21 Mercury Remote Control Switch Signal Compare Failure?

Possible causes include faulty remote control switch signal, wiring issues, or a malfunction in the central locking system.

3. How can I diagnose the OBDII code B1D21 Mercury Remote Control Switch Signal Compare Failure?

Diagnosing this code typically involves using a diagnostic scanner to read the code, checking the wiring and connections related to the remote control system, and testing the functionality of the remote control switch.

4. What are the repair options for OBDII code B1D21 Mercury Remote Control Switch Signal Compare Failure?

Repair options may include fixing or replacing the remote control switch, repairing any damaged wiring, or addressing issues with the central locking system.

5. Can I fix OBDII code B1D21 Mercury Remote Control Switch Signal Compare Failure myself?

Depending on your level of automotive expertise, you may be able to diagnose and repair this issue yourself. However, if you are unsure or unfamiliar with electrical systems, it's advisable to seek professional help.

6. Is it safe to continue driving with OBDII code B1D21 Mercury Remote Control Switch Signal Compare Failure?

While the vehicle may still be drivable with this code, it's important to address the issue promptly to avoid potential inconvenience or safety concerns related to the remote control functions.

7. How much does it cost to repair OBDII code B1D21 Mercury Remote Control Switch Signal Compare Failure?

The cost of repair can vary depending on the exact cause of the issue, the parts needed, and the labor rates of the repair shop. It's recommended to obtain quotes from different mechanics or dealerships.

8. Can weather conditions affect OBDII code B1D21 Mercury Remote Control Switch Signal Compare Failure?

Extreme weather conditions or exposure to moisture can potentially impact the remote control system and contribute to issues related to this OBDII code.

9. Are there any preventive measures to avoid OBDII code B1D21 Mercury Remote Control Switch Signal Compare Failure?

Regularly inspecting the remote control system, keeping it clean and dry, and addressing any issues promptly can help prevent or minimize the occurrence of this code.

10. How long does it typically take to repair OBDII code B1D21 Mercury Remote Control Switch Signal Compare Failure?

The repair time can vary depending on the complexity of the issue and the availability of parts. Simple fixes may take a short time, while more involved repairs could require more time.