AutoCodes – Lexus – B279A Lexus

B279A Lexus Code - Theft Deterrent System Communication Line High Fixation

Quick Answer

The Diagnostic Trouble Code (DTC) will be set in the Engine Control Module (ECM) when the communication line (IMI - EFIO) between the Engine Control Module and the Certification ECU (Smart Key ECU Assembly) is stuck high. Common causes include Faulty Certification ECU (Smart Key ECU Assembly), Certification ECU harness is open or shorted, Certification 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: B279A Lexus indicates Theft Deterrent System Communication Line High Fixation.
Common causes: Common causes include Faulty Certification ECU (Smart Key ECU Assembly), Certification ECU harness is open or shorted, Certification 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 11,467

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 Jan 17, 2023

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code B279A Lexus Description

OBDII Code B279A Lexus - Theft Deterrent System Communication Line High Fixation - AutoCodes.com — B279A Lexus Code - Theft Deterrent System Communication Line High Fixation

What does this mean?

What are the Possible Causes of the DTC B279A Lexus?

Faulty Certification ECU (Smart Key ECU Assembly)
Certification ECU harness is open or shorted
Certification ECU circuit poor electrical connection
Faulty Engine Control Module (ECM)

How to Fix the DTC B279A Lexus?

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 B279A Lexus 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 B279A Lexus code?

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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 B279A Lexus Code

1. What are the common symptoms of OBDII code B279A in a Lexus related to the Theft Deterrent System Communication Line High Fixation?

- Common symptoms include issues with the theft deterrent system, such as difficulty starting the vehicle or the security light staying illuminated.

2. What could cause the OBDII code B279A to appear in a Lexus?

- The code B279A in a Lexus is often caused by a malfunction in the communication line of the theft deterrent system, which can be triggered by wiring faults or a faulty module.

3. How can I diagnose the OBDII code B279A in my Lexus?

- Diagnosis typically involves using an OBDII scanner to retrieve the specific code, followed by inspecting the wiring and connections related to the theft deterrent system for any visible issues.

4. Can I still drive my Lexus with the OBDII code B279A present?

- It is not recommended to drive the vehicle with the B279A code active, as it may indicate a potential security system malfunction that could lead to starting or other issues.

5. Are there any DIY repair tips for fixing the Theft Deterrent System Communication Line High Fixation issue in a Lexus?

- DIY repair tips may include checking and repairing any damaged wiring, ensuring all connections are secure, and resetting the system by disconnecting the battery for a few minutes.

6. Is it necessary to take my Lexus to a dealership for repair when experiencing the B279A code?

- While a dealership may have specialized knowledge and tools, an experienced mechanic or technician should be able to diagnose and repair the issue related to the B279A code in a Lexus.

7. How much does it typically cost to repair the OBDII code B279A in a Lexus?

- The cost of repair can vary depending on the exact cause of the code, but it may involve expenses for parts replacement, labor, and diagnostic fees.

8. Will resetting the OBDII code B279A in my Lexus resolve the issue permanently?

- Resetting the code may temporarily clear the warning, but unless the underlying cause is fixed, the code is likely to reappear and the issue persist.

9. Can the OBDII code B279A in a Lexus be indicative of other problems with the vehicle?

- While the code specifically relates to the theft deterrent system communication line, it is important to address this issue promptly as it may affect the overall functionality of the vehicle's security system.

10. How long does it take to repair the B279A code in a Lexus?

- The repair time can vary based on the complexity of the issue, accessibility of components, and the expertise of the technician, but it may range from a few hours to a full day.