AutoCodes – Lexus – B1638 Lexus

B1638 Lexus Code - Rear Airbag Sensor Assembly Left Initialization Incomplete

Quick Answer

The Side Collision Sensor Left (LH) circuit (to determine deployment of the Curtain Shield Airbag Assembly LH) is composed of the Center Airbag Sensor Assembly, Side Airbag Sensor LH, and Rear Airbag Sensor LH. Common causes include Faulty Rear Airbag Sensor Left (LH), Rear Airbag Sensor Left harness is open or shorted, Rear Airbag Sensor Left 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: B1638 Lexus indicates Rear Airbag Sensor Assembly Left Initialization Incomplete.
Common causes: Common causes include Faulty Rear Airbag Sensor Left (LH), Rear Airbag Sensor Left harness is open or shorted, Rear Airbag Sensor Left 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 2,557

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 Oct 10, 2022

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code B1638 Lexus Description

The Side Collision Sensor Left (LH) circuit (to determine deployment of the Curtain Shield Airbag Assembly LH) is composed of the Center Airbag Sensor Assembly, Side Airbag Sensor LH, and Rear Airbag Sensor LH. The Rear Airbag Sensor LH detects impacts to the vehicle and sends signals to the Center Airbag Sensor Assembly to determine if the airbag should be deployed. The Diagnostic Trouble Code (DTC) is stored when a malfunction is detected for the rear side collision LH circuit (to determine deployment of the Curtain Shield Airbag Assembly LH).

OBDII Code B1638 Lexus - Rear Airbag Sensor Assembly Left Initialization Incomplete - AutoCodes.com — B1638 Lexus Code - Rear Airbag Sensor Assembly Left Initialization Incomplete

What does this mean?

What are the Possible Causes of the DTC B1638 Lexus?

Faulty Rear Airbag Sensor Left (LH)
Rear Airbag Sensor Left harness is open or shorted
Rear Airbag Sensor Left circuit poor electrical connection
Faulty Center Airbag Sensor Assembly

How to Fix the DTC B1638 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 B1638 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 B1638 Lexus code?

Need more information on how to fix the B1638 Lexus code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the B1638 Lexus code diagnosed by a professional: Find a repair shop in your area

Precautions for SRS “AIR BAG” and “SEAT BELT PRE-TENSIONER” Service

Never probe the electrical connectors on air bag, side air curtain modules or seat belts.
Never disassemble or tamper with safety belt buckle/retractor pretensioners, adaptive load limiting retractors, safety belt inflators, or probe the electrical connectors.
Do not use electrical test equipment to check SRS circuits unless instructed to in this Service Manual.
Before servicing the SRS, turn ignition switch OFF, disconnect both battery cables and wait at least 3 minutes. For approximately 3 minutes after the cables are removed, it is still possible for the air bag and seat belt pre-tensioner to deploy. Therefore, do not work on any SRS connectors or wires until at least 3 minutes have passed.

Failure to follow this instruction may result in the accidental deployment of these modules, which increases the risk of serious personal injury or death.

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 B1638 Lexus Code

1. What are the common symptoms of OBDII code B1638 in a Lexus related to the Rear Airbag Sensor Assembly Left Initialization Incomplete?

The common symptoms include the airbag warning light remaining illuminated on the dashboard and potential issues with the deployment of the left rear airbag.

2. What are the potential causes of OBDII code B1638 in a Lexus?

Potential causes of this code can include a faulty rear airbag sensor assembly, wiring issues, or a malfunction in the airbag control module.

3. How can I diagnose the cause of OBDII code B1638 in my Lexus?

Diagnosis typically involves using a professional OBDII scanner to retrieve the specific error codes, inspecting the wiring and connections related to the left rear airbag sensor assembly, and testing the components for proper functionality.

4. Can I still drive my Lexus with OBDII code B1638 present?

It is not recommended to drive your Lexus with this code present, as it indicates a potential issue with the left rear airbag system, which can compromise your safety in the event of a collision.

5. How can I reset OBDII code B1638 in my Lexus after addressing the issue?

Once the underlying issue causing the code has been resolved, you can reset the code using an OBDII scanner or by disconnecting the car battery for a few minutes to clear the error.

6. Is it possible to repair OBDII code B1638 in my Lexus by myself?

While some DIY enthusiasts may attempt to address this code themselves, it is recommended to seek professional help, especially when dealing with airbag systems, to ensure proper diagnosis and repair.

7. How much does it typically cost to repair OBDII code B1638 in a Lexus?

The cost of repair can vary depending on the specific cause of the code, but it may involve replacing the rear airbag sensor assembly, addressing wiring issues, or reprogramming the airbag control module, which can range from a hundred to several hundred dollars.

8. Can OBDII code B1638 cause the airbags to deploy unintentionally?

While this code typically indicates an issue with the initialization of the left rear airbag sensor assembly, it is unlikely to cause the airbags to deploy unintentionally. However, it is crucial to address the problem promptly to ensure the airbags function correctly in case of an accident.

9. Are there any safety precautions I should take if OBDII code B1638 appears in my Lexus?

If you encounter this code, it is essential to refrain from attempting any repairs unless you have the necessary expertise. Additionally, avoid driving the vehicle until the issue has been properly diagnosed and resolved to prevent potential safety hazards.

10. How long does it take to repair OBDII code B1638 in a Lexus?

The repair time can vary depending on the cause of the code and the availability of parts. In general, it may take a few hours to a day to diagnose and repair the issue related to the Rear Airbag Sensor Assembly Left Initialization Incomplete.