AutoCodes – Honda – B1640 Honda

B1640 Honda Code - RF Unit Not Connected

Quick Answer

The remote is equipped with a keyless transmitter, and all doors can be locked and unlocked by a lock/unlock button operation, even from a remote distance from the vehicle. Common causes include Faulty Keyless Access Control Unit, Keyless Access Control Unit harness is open or shorted, Keyless Access Control Unit 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: B1640 Honda indicates RF Unit Not Connected.
Common causes: Common causes include Faulty Keyless Access Control Unit, Keyless Access Control Unit harness is open or shorted, Keyless Access Control Unit 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 6,171

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 Jun 06, 2019

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code B1640 Honda Description

The remote is equipped with a keyless transmitter, and all doors can be locked and unlocked by a lock/unlock button operation, even from a remote distance from the vehicle. When the remote lock button or the remote unlock button is pressed, the keyless transmitter sends the applicable switch signal to the keyless access control unit. After receiving the authentication at the Keyless Access Control Unit, then the door lock signals are sent to MICU through B-CAN.

OBDII Code B1640 Honda - RF Unit Not Connected - AutoCodes.com — B1640 Honda Code - RF Unit Not Connected

What does this mean?

What are the Possible Causes of the DTC B1640 Honda?

Faulty Keyless Access Control Unit
Keyless Access Control Unit harness is open or shorted
Keyless Access Control Unit circuit poor electrical connection

How to Fix the DTC B1640 Honda?

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 B1640 Honda 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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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 B1640 Honda Code

1. What are the common symptoms of OBDII code B1640 Honda (RF Unit Not Connected)?

- Common symptoms include a malfunctioning remote key fob, inability to lock/unlock the vehicle remotely, and issues with the vehicle's keyless entry system.

2. What are the possible causes of OBDII code B1640 Honda?

- The code may be triggered by a disconnected or faulty RF unit, a damaged key fob, a weak battery in the key fob, or issues with the vehicle's immobilizer system.

3. How can I diagnose the cause of OBDII code B1640 Honda?

- Diagnose by checking the connection of the RF unit, testing the key fob battery, inspecting the key fob for damage, and verifying the immobilizer system's functionality.

4. Can I repair OBDII code B1640 Honda on my own?

- Depending on the cause, you may be able to repair the issue on your own by reconnecting the RF unit, replacing the key fob battery, or reprogramming the key fob. For complex issues, professional help may be needed.

5. Is it safe to drive with OBDII code B1640 Honda active?

- While the code itself may not affect the drivability of the vehicle, it is recommended to address the issue promptly to ensure the proper functioning of the keyless entry system and immobilizer.

6. How much does it typically cost to fix OBDII code B1640 Honda?

- The cost of fixing this code can vary depending on the cause of the issue. Simple fixes like replacing a key fob battery may be inexpensive, while more complex repairs involving the RF unit or immobilizer system can be more costly.

7. Can a disconnected RF unit cause other problems in the vehicle?

- A disconnected RF unit can potentially lead to issues with the keyless entry system, immobilizer system, and remote locking/unlocking functions of the vehicle.

8. Are there any preventive measures to avoid OBDII code B1640 Honda?

- Regularly checking the condition of the key fob, ensuring the RF unit is securely connected, and replacing the key fob battery as needed can help prevent issues related to this OBDII code.

9. Does OBDII code B1640 Honda affect the vehicle's performance?

- This code typically does not affect the vehicle's engine performance or handling. However, it can impact the convenience and security features of the vehicle.

10. How long does it usually take to repair OBDII code B1640 Honda?

- The repair time for this code can vary based on the cause of the issue and the complexity of the repair. Simple fixes may take a short amount of time, while more involved repairs could take longer.