AutoCodes – Toyota – B2278 Toyota

B2278 Toyota Code - Engine Switch Circuit Malfunction

Quick Answer

This Diagnostic Trouble Code (DTC) is output when a malfunction is detected between the Main Body ECU and the engine switch, or either of the switches inside the engine switch is malfunctioning. Common causes include Faulty Engine Switch, Engine Switch harness is open or shorted, Engine 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: B2278 Toyota indicates Engine Switch Circuit Malfunction.
Common causes: Common causes include Faulty Engine Switch, Engine Switch harness is open or shorted, Engine 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 5,911

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 Oct 29, 2019

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code B2278 Toyota Description

This Diagnostic Trouble Code (DTC) is output when a malfunction is detected between the Main Body ECU and the engine switch, or either of the switches inside the engine switch is malfunctioning.

OBDII Code B2278 Toyota - Engine Switch Circuit Malfunction - AutoCodes.com — B2278 Toyota Code - Engine Switch Circuit Malfunction

What does this mean?

What are the Possible Causes of the DTC B2278 Toyota?

Faulty Engine Switch
Engine Switch harness is open or shorted
Engine Switch circuit poor electrical connection
Faulty Main Body ECU

How to Fix the DTC B2278 Toyota?

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 B2278 Toyota 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 more information on how to fix the B2278 Toyota code? Get Access to Factory Service Manuals

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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 B2278 Toyota Code

1. What are the common symptoms of OBDII code B2278 Toyota (Engine Switch Circuit Malfunction)?

Symptoms may include difficulty starting the engine, intermittent stalling, failure of the engine to turn off, and illuminated warning lights on the dashboard.

2. What are the possible causes of OBDII code B2278 Toyota?

Potential causes include a faulty engine switch, damaged wiring or connectors in the engine switch circuit, issues with the engine control module (ECM), or a malfunctioning ignition key cylinder.

3. How can I diagnose the cause of OBDII code B2278 Toyota?

Diagnosis typically involves checking the engine switch operation, inspecting the wiring and connectors in the circuit, testing the ignition key cylinder, and using a diagnostic scan tool to retrieve trouble codes stored in the ECM.

4. Can I repair OBDII code B2278 Toyota on my own?

Depending on your mechanical skills and access to tools, you may be able to address this issue. However, it is recommended to consult a professional mechanic for an accurate diagnosis and proper repair.

5. Is it safe to continue driving with OBDII code B2278 Toyota present?

Driving with this code active may lead to potential safety hazards, such as unexpected stalling or the inability to turn off the engine. It is advisable to address the issue promptly to prevent further complications.

6. How much does it typically cost to repair OBDII code B2278 Toyota?

Repair costs can vary depending on the specific cause of the issue, labor rates in your area, and the parts needed for the repair. It is best to obtain quotes from different mechanics to compare prices.

7. Will resetting the trouble codes make OBDII code B2278 Toyota disappear?

Resetting the trouble codes may temporarily clear the warning lights, but if the underlying issue causing the code is not addressed, the code is likely to reappear once the problem is detected again.

8. Can extreme weather conditions cause OBDII code B2278 Toyota to trigger?

Extreme weather conditions, such as extreme heat or cold, can potentially affect the operation of electrical components in the engine switch circuit, leading to the triggering of this code.

9. How long does it take to repair OBDII code B2278 Toyota?

The repair time can vary depending on the complexity of the issue and the availability of parts. Some repairs may be completed within a few hours, while others may take longer if extensive diagnosis and troubleshooting are required.

10. Is there a way to prevent OBDII code B2278 Toyota from occurring in the future?

Regular maintenance of the engine switch, wiring, and connectors, as well as addressing any issues promptly, can help prevent this code from occurring in the future.