AutoCodes – Honda – B1800 Honda

B1800 Honda Code - Communication Bus Line Error

Quick Answer

The Multiplex Integrated Control Unit (MICU) has encountered a Communication Bus Line Error with other control units. Common causes include Faulty Multiplex Integrated Control Unit (MICU), Multiplex Integrated Control Unit (MICU) harness is open or shorted, Multiplex Integrated Control Unit (MICU) 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: B1800 Honda indicates Communication Bus Line Error.
Common causes: Common causes include Faulty Multiplex Integrated Control Unit (MICU), Multiplex Integrated Control Unit (MICU) harness is open or shorted, Multiplex Integrated Control Unit (MICU) 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 1,868

How popular is this code, among other codes? Low

Repair Importance Level

Urgent (Diagnose now) (3 / 3)

Repair Difficulty Level

Advanced (Pro) (3 / 3)

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Table of contents Created and updated by William Orellana on Sep 24, 2019

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code B1800 Honda Description

The Multiplex Integrated Control Unit (MICU) has encountered a Communication Bus Line Error with other control units.

OBDII Code B1800 Honda - Communication Bus Line Error - AutoCodes.com — B1800 Honda Code - Communication Bus Line Error

What does this mean?

What are the Possible Causes of the DTC B1800 Honda?

Faulty Multiplex Integrated Control Unit (MICU)
Multiplex Integrated Control Unit (MICU) harness is open or shorted
Multiplex Integrated Control Unit (MICU) circuit poor electrical connection

How to Fix the DTC B1800 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 B1800 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.

Need more information about the B1800 Honda code?

Need more information on how to fix the B1800 Honda code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the B1800 Honda 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 B1800 Honda Code

1. What is OBDII code B1800 Honda indicating?

Code B1800 in Honda vehicles refers to a Communication Bus Line Error, which means there is a communication issue on the bus network between modules.

2. What are the common symptoms of OBDII code B1800 in a Honda?

Common symptoms of B1800 may include the malfunction indicator light (MIL) illuminating, communication errors with various vehicle systems, and potential loss of certain functionalities.

3. What are the possible causes of OBDII code B1800 in a Honda?

Causes of B1800 can include faulty wiring or connectors in the communication network, issues with the communication modules, software glitches, or water damage.

4. How can I diagnose OBDII code B1800 in my Honda?

Diagnosing B1800 typically involves using a diagnostic scanner to read the code, checking for related codes, inspecting wiring and connectors, and performing communication tests on the affected network.

5. Can OBDII code B1800 in a Honda be fixed easily?

Fixing B1800 may range from simple tasks like checking and repairing wiring connections to more complex procedures like module reprogramming or replacement, depending on the root cause.

6. Are there any DIY repair tips for resolving OBDII code B1800 in a Honda?

DIY repair tips for B1800 include checking and cleaning communication connectors, ensuring proper grounding, and inspecting for any visible wiring issues before seeking professional help if needed.

7. Is it safe to continue driving with OBDII code B1800 present in a Honda?

It is generally not recommended to drive with an unresolved B1800 code, as it may lead to further communication failures between critical vehicle systems.

8. Can a faulty battery or alternator cause OBDII code B1800 to trigger in a Honda?

While a weak battery or alternator can sometimes affect electrical systems, they are not common direct causes of B1800. It is important to address the code specifically to resolve the communication issue.

9. How much does it cost to repair OBDII code B1800 in a Honda at a dealership or repair shop?

Repair costs for B1800 can vary depending on the exact cause, location, and labor rates, but it is advisable to obtain quotes from reputable service centers for an accurate estimate.

10. Does resetting the OBDII code B1800 clear the issue permanently in a Honda?

Resetting the code may temporarily clear the MIL, but if the underlying communication problem persists, the code is likely to reappear. It is crucial to diagnose and address the root cause for a lasting solution.