AutoCodes – Lexus – B1903 Lexus

B1903 Lexus Code - Short to Positive in Front Pretensioner Squib Right Circuit

Quick Answer

The Front Pretensioner Squib Right (RH) Circuit consists of the Center Airbag Sensor Assembly and Front Seat Outer Belt Assembly Right (RH). Common causes include Faulty Front Seat Outer Belt Assembly Right (RH) (Front Pretensioner Squib Right), Front Seat Outer Belt Assembly Right harness is open or shorted, Front Seat Outer Belt Assembly Right 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: B1903 Lexus indicates Short to Positive in Front Pretensioner Squib Right Circuit.
Common causes: Common causes include Faulty Front Seat Outer Belt Assembly Right (RH) (Front Pretensioner Squib Right), Front Seat Outer Belt Assembly Right harness is open or shorted, Front Seat Outer Belt Assembly Right 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 865

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 Dec 03, 2022

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code B1903 Lexus Description

The Front Pretensioner Squib Right (RH) Circuit consists of the Center Airbag Sensor Assembly and Front Seat Outer Belt Assembly Right (RH). This circuit instructs the Supplemental Restraint System (SRS) to deploy when the deployment conditions are met. The Diagnostic Trouble Code (DTC) is recorded when a malfunction is detected in the Front Pretensioner Squib Right Circuit.

OBDII Code B1903 Lexus - Short to Positive in Front Pretensioner Squib Right Circuit - AutoCodes.com — B1903 Lexus Code - Short to Positive in Front Pretensioner Squib Right Circuit

What does this mean?

What are the Possible Causes of the DTC B1903 Lexus?

Faulty Front Seat Outer Belt Assembly Right (RH) (Front Pretensioner Squib Right)
Front Seat Outer Belt Assembly Right harness is open or shorted
Front Seat Outer Belt Assembly Right circuit poor electrical connection
Faulty Center Airbag Sensor Assembly

How to Fix the DTC B1903 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 B1903 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 B1903 Lexus code?

Need more information on how to fix the B1903 Lexus code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the B1903 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 B1903 Lexus Code

1. What are the common symptoms of OBDII code B1903 in a Lexus?

- The common symptoms include the airbag warning light illuminating on the dashboard and possible non-deployment of the front right seatbelt pretensioner in the event of a collision.

2. What does the OBDII code B1903 for Lexus indicate?

- The code B1903 indicates a "Short to Positive in Front Pretensioner Squib Right Circuit" in the airbag system of a Lexus vehicle.

3. What are the potential causes of the B1903 fault code in a Lexus?

- The code B1903 can be triggered by issues such as a short circuit to a positive wire in the front pretensioner squib right circuit, faulty wiring, a defective pretensioner squib, or a problem with the airbag control module.

4. How serious is the OBDII code B1903 in a Lexus?

- The B1903 code is considered a serious issue as it relates to the proper functioning of the front right seatbelt pretensioner in the event of a collision. It is crucial to address this problem promptly for safety reasons.

5. Can I continue driving my Lexus with the B1903 fault code?

- It is not recommended to drive the vehicle with the B1903 fault code present, as it may compromise the effectiveness of the front right seatbelt pretensioner in case of an accident. Immediate attention is advised.

6. How can I diagnose and repair the B1903 fault code in my Lexus?

- Diagnosis typically involves inspecting the wiring harness, connectors, and the front right seatbelt pretensioner squib for any visible damage. Repair may involve repairing or replacing damaged components as necessary.

7. Can I reset the B1903 fault code in my Lexus myself?

- While you can attempt to clear the fault code using an OBDII scanner, it is crucial to address the underlying issue causing the code before resetting it. Ignoring the problem without proper repair may lead to safety risks.

8. Is it necessary to visit a dealership for fixing the B1903 fault code in a Lexus?

- While a dealership may have specialized knowledge and tools for diagnosing and repairing the B1903 fault code, an experienced independent mechanic or auto repair shop familiar with airbag systems can also address this issue effectively.

9. How can I prevent the B1903 fault code from recurring in my Lexus?

- Regular maintenance and inspections of the airbag system, including the seatbelt pretensioners, can help prevent issues like the B1903 code. Promptly addressing any warning lights or unusual symptoms is key to preventing recurrences.

10. Is the repair for the B1903 fault code covered under warranty for Lexus vehicles?

- Coverage for repairs related to the B1903 fault code may vary depending on the vehicle's warranty status and the specific circumstances. It is advisable to check with the dealership or refer to the warranty documentation for more information.