AutoCodes – Lexus – B1856 Lexus

B1856 Lexus Code - Open In Rear Side Squib Left Circuit

Quick Answer

The Rear Side Squib Left (LH) Circuit consists of the Center Airbag Sensor Assembly and the Rear Seat Side Airbag Assembly Left (LH). Common causes include Faulty Rear Seat Side Airbag Assembly Left (LH) (Rear Side Squib Left Circuit), Rear Seat Side Airbag Assembly Left harness is open or shorted, Rear Seat Side Airbag Assembly 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: B1856 Lexus indicates Open In Rear Side Squib Left Circuit.
Common causes: Common causes include Faulty Rear Seat Side Airbag Assembly Left (LH) (Rear Side Squib Left Circuit), Rear Seat Side Airbag Assembly Left harness is open or shorted, Rear Seat Side Airbag Assembly 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 10,368

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 Jul 08, 2019

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 B1856 Lexus Description

The Rear Side Squib Left (LH) Circuit consists of the Center Airbag Sensor Assembly and the Rear Seat Side Airbag Assembly Left (LH). The circuit instructs the Supplemental Restraint System (SRS) to deploy when deployment conditions are met. The Diagnostic Trouble Code (DTC) is stored when a malfunction is detected in the Rear Side Squib Left Circuit.

OBDII Code B1856 Lexus - Open In Rear Side Squib Left Circuit - AutoCodes.com — B1856 Lexus Code - Open In Rear Side Squib Left Circuit

What does this mean?

What are the Possible Causes of the DTC B1856 Lexus?

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

How to Fix the DTC B1856 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 B1856 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 B1856 Lexus code?

Need more information on how to fix the B1856 Lexus code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the B1856 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 B1856 Lexus Code

1. What are the common symptoms of OBDII code B1856 in a Lexus related to the Rear Side Squib Left Circuit?

- Common symptoms may include the airbag warning light illuminating on the dashboard and potential non-deployment of the airbag in the event of a collision.

2. What are the possible causes of the Open In Rear Side Squib Left Circuit OBDII code B1856 in a Lexus?

- Possible causes include a faulty rear side airbag squib, damaged wiring or connectors in the circuit, or a problem with the airbag control module.

3. How can I diagnose the Open In Rear Side Squib Left Circuit issue in my Lexus triggering the B1856 code?

- Diagnosis typically involves using a professional OBDII scanner to read the code, inspecting the wiring and connectors for damage, and testing the rear side airbag squib for continuity.

4. Can I still drive my Lexus with the B1856 OBDII code indicating an Open In Rear Side Squib Left Circuit?

- It is not recommended to drive the vehicle with an active airbag system fault code, as it may compromise the safety of the occupants in the event of a collision.

5. Is it possible to reset the B1856 code related to the Open In Rear Side Squib Left Circuit in a Lexus without fixing the underlying issue?

- While you can clear the code temporarily, it will likely reappear until the root cause of the problem is addressed and resolved.

6. How can I repair the Open In Rear Side Squib Left Circuit problem triggering the B1856 code in my Lexus?

- Repair options may include replacing the faulty rear side airbag squib, repairing damaged wiring or connectors, or reprogramming the airbag control module.

7. Are there any safety precautions I should take when working on the airbag system to fix the B1856 code in my Lexus?

- It is crucial to disconnect the vehicle's battery and wait at least 10 minutes before starting any work on the airbag system to prevent accidental deployment.

8. Can a DIY enthusiast without advanced automotive knowledge fix the B1856 OBDII code related to the Open In Rear Side Squib Left Circuit in a Lexus?

- While some basic troubleshooting steps can be taken, it is recommended to seek professional help when dealing with airbag system issues due to safety concerns.

9. How long does it typically take to repair the Open In Rear Side Squib Left Circuit problem causing the B1856 code in a Lexus?

- The repair time can vary depending on the exact cause of the issue, but it may take a few hours to a day for a professional technician to diagnose and fix the problem.

10. Will fixing the B1856 code related to the Rear Side Squib Left Circuit in my Lexus require a visit to the dealership or can it be done at an independent auto repair shop?

- The repair can typically be done at an independent auto repair shop that has experience working on Lexus vehicles and airbag systems, potentially offering cost savings compared to dealership service.