AutoCodes – Generic – B1638

B1638 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 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.

Save to My Repairs My Repairs

AI answers can be wrong. Verify repairs with testing. Open full chat

Code Popularity 11,603

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 10, 2022

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
Add Comment

💬 Need more help? Ask Coddy for instant answers — it's free!

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

What does this mean?

What are the Possible Causes of the DTC B1638?

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?

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 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 code?

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

Need Help with the Code?

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

Information for Specific Makes

B1638 Chrysler — Right High Beam Control Circuit High
B1638 Dodge — Right High Beam Control Circuit High
B1638 Jeep — Right High Beam Control Circuit High
B1638 Lexus — Rear Airbag Sensor Assembly Left Initialization Incomplete
B1638 RAM — Right High Beam Control Circuit High
B1638 Scion — Rear Airbag Sensor Assembly Left Initialization Incomplete
B1638 Toyota — Rear Airbag Sensor Assembly Left Initialization Incomplete

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 Code

1. What are the common symptoms of OBDII code B1638 (Rear Airbag Sensor Assembly Left Initialization Incomplete)?

The common symptoms include the airbag warning light illuminating on the dashboard and a potential loss of functionality in the rear left airbag system.

2. What can cause OBDII code B1638 to trigger?

This code is typically triggered when the rear airbag sensor assembly on the left side of the vehicle fails to initialize properly, often due to faulty wiring, sensor malfunctions, or issues with the airbag control module.

3. How serious is OBDII code B1638?

While the vehicle may still be operable with this code present, it is crucial to address it promptly to ensure the proper functioning of the rear airbag system in case of an accident.

4. How can I diagnose OBDII code B1638?

Diagnosing this code usually involves using a diagnostic scanner to retrieve the specific fault codes stored in the airbag system, followed by a thorough inspection of the rear airbag sensor assembly and related components.

5. Can I repair OBDII code B1638 on my own?

While some experienced DIYers may be able to troubleshoot and repair this code, it is recommended to seek assistance from a professional mechanic or technician due to the complexity and safety considerations involved.

6. What are some tips for repairing OBDII code B1638?

Repair tips may include checking the wiring harness for damage, testing the rear airbag sensor assembly for proper functionality, and resetting the airbag control module after any repairs have been made.

7. Is it safe to drive with OBDII code B1638 present?

It is not ideal to drive with this code active, as it indicates a potential issue with the rear airbag system that may compromise passenger safety in the event of a collision.

8. How much does it cost to repair OBDII code B1638?

The cost of repairing this code can vary depending on the underlying cause of the issue, the extent of the repairs needed, and labor rates in your area. It is advisable to obtain estimates from reputable repair shops.

9. Can OBDII code B1638 affect other vehicle systems?

While this code specifically relates to the rear airbag sensor assembly on the left side, it is essential to address it promptly to prevent any potential impact on the overall airbag system's functionality.

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

The repair time can vary based on the diagnosis, parts availability, and the complexity of the repair process. In some cases, it may be a relatively quick fix, while in others, it may require more extensive troubleshooting and repairs.