AutoCodes – Generic – B278C

B278C Code - Lost Communication With Power Source Control

Quick Answer

This Diagnostic Trouble Code (DTC) is stored when Local Interconnect Network (LIN) communication between the Certification ECU (Smart Key ECU Assembly) and Power Management Control ECU stops for 10 seconds or more. Common causes include Faulty Power Management Control ECU, Power Management Control ECU harness is open or shorted, Power Management Control ECU 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: B278C indicates Lost Communication With Power Source Control.
Common causes: Common causes include Faulty Power Management Control ECU, Power Management Control ECU harness is open or shorted, Power Management Control ECU 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 3,677

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 Jan 27, 2020

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code B278C Description

OBDII Code B278C - Lost Communication With Power Source Control - AutoCodes.com — B278C Code - Lost Communication With Power Source Control

What does this mean?

What are the Possible Causes of the DTC B278C?

Faulty Power Management Control ECU
Power Management Control ECU harness is open or shorted
Power Management Control ECU circuit poor electrical connection
Faulty Certification ECU (Smart Key ECU Assembly)

How to Fix the DTC B278C?

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 B278C 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 B278C code?

Need more information on how to fix the B278C code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the B278C code diagnosed by a professional: Find a repair shop in your area

Information for Specific Makes

B278C Lexus — Lost Communication With Power Source Control
B278C Nissan — Electric Compressor Communication Error
B278C Scion — Lost Communication With Power Source Control
B278C Toyota — Lost Communication With Power Source Control

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 B278C Code

1. What are common symptoms of OBDII code B278C (Lost Communication With Power Source Control)?

- Common symptoms include issues with power windows, power door locks, interior lighting, and other electrical components in the vehicle.

2. What are the possible causes of OBDII code B278C?

- The code B278C can be triggered by a faulty power source control module, wiring issues, blown fuses, or a malfunctioning communication network in the vehicle.

3. How can I diagnose the cause of OBDII code B278C?

- To diagnose the cause of B278C, you may need to perform a thorough inspection of the power source control module, check the wiring connections, and use a diagnostic scanner to assess the communication network.

4. Can a DIY enthusiast repair OBDII code B278C at home?

- Repairing OBDII code B278C may require advanced automotive diagnostic skills and tools. It is recommended to seek assistance from a professional mechanic or technician for proper diagnosis and repair.

5. Is it safe to continue driving with OBDII code B278C present?

- It is not recommended to continue driving with OBDII code B278C present, as it can lead to further electrical system issues and potentially affect the overall performance of the vehicle.

6. How much does it typically cost to repair OBDII code B278C?

- The cost of repairing OBDII code B278C can vary depending on the specific cause of the issue. Repair costs may include parts replacement, labor fees, and diagnostic charges.

7. Can a low battery voltage trigger OBDII code B278C?

- Yes, a low battery voltage or electrical system issues can sometimes trigger OBDII code B278C due to disruptions in the power source control module communication.

8. Are there any preventive measures to avoid OBDII code B278C in the future?

- To prevent OBDII code B278C, it is recommended to regularly check and maintain the vehicle's electrical system, including the power source control module and related components.

9. How long does it take to repair OBDII code B278C?

- The repair time for OBDII code B278C can vary depending on the complexity of the issue and the availability of parts. It is best to consult with a professional technician for an accurate estimate.

10. Can resetting the OBDII system clear the B278C code temporarily?

- Resetting the OBDII system may temporarily clear the B278C code, but it is essential to address the underlying issue causing the code to prevent it from reoccurring.