AutoCodes – Mitsubishi – B1B21 Mitsubishi

B1B21 Mitsubishi Code - Right Side Curtain Squib 1 Circuit High

Quick Answer

When powered, the Occupant Restraint Controller (ORC) sends a test current to the squibs to verify the integrity of the squib and the wiring. Common causes include Faulty Right Side Curtain Squib 1, Right Side Curtain Squib 1 harness is open or shorted, Right Side Curtain Squib 1 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: B1B21 Mitsubishi indicates Right Side Curtain Squib 1 Circuit High.
Common causes: Common causes include Faulty Right Side Curtain Squib 1, Right Side Curtain Squib 1 harness is open or shorted, Right Side Curtain Squib 1 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 1,156

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 Aug 16, 2019

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code B1B21 Mitsubishi Description

When powered, the Occupant Restraint Controller (ORC) sends a test current to the squibs to verify the integrity of the squib and the wiring. These circuits are maintained in a floating configuration at the module, (connected to neither power nor ground), as protection against inadvertent deployment. The use of the Supplemental Restraint System (SRS) Load Tool Adapter provides a test point, as well as a method for opening the shorting bar connections within the harness connector. The ORC sends out a 40 mA diagnostic current on each squib voltage supply circuit at power up and every 500 ms thereafter while the ignition is on.

OBDII Code B1B21 Mitsubishi - Right Side Curtain Squib 1 Circuit High - AutoCodes.com — B1B21 Mitsubishi Code - Right Side Curtain Squib 1 Circuit High

What does this mean?

What are the Possible Causes of the DTC B1B21 Mitsubishi?

Faulty Right Side Curtain Squib 1
Right Side Curtain Squib 1 harness is open or shorted
Right Side Curtain Squib 1 circuit poor electrical connection
Faulty Right Side Curtain Airbag
Faulty Occupant Restraint Controller (ORC)

How to Fix the DTC B1B21 Mitsubishi?

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 B1B21 Mitsubishi 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 B1B21 Mitsubishi code?

Need more information on how to fix the B1B21 Mitsubishi code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the B1B21 Mitsubishi 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 B1B21 Mitsubishi Code

1. What are the common symptoms of OBDII code B1B21 in a Mitsubishi related to the Right Side Curtain Squib 1 Circuit High?

The common symptoms include the airbag warning light staying illuminated on the dashboard and potential loss of functionality in the right side curtain airbag system.

2. What are the possible causes of OBDII code B1B21 indicating Right Side Curtain Squib 1 Circuit High in a Mitsubishi?

Possible causes may include a faulty squib (airbag initiator), wiring issues in the right side curtain airbag circuit, or a problem with the airbag control module.

3. How can I diagnose the OBDII code B1B21 in a Mitsubishi for the Right Side Curtain Squib 1 Circuit High issue?

Diagnosis typically involves using an OBDII scanner to retrieve the specific code, followed by inspecting the right side curtain airbag system components for any visible damage or loose connections.

4. Can I continue driving my Mitsubishi with OBDII code B1B21 related to Right Side Curtain Squib 1 Circuit High?

It is not advisable to continue driving the vehicle with this code present, as it indicates a potential issue with the right side curtain airbag system, which could affect its deployment in the event of a collision.

5. What are the repair options for resolving OBDII code B1B21 in a Mitsubishi signaling Right Side Curtain Squib 1 Circuit High?

Repair options may include replacing the faulty squib, repairing any damaged wiring, or resetting the airbag control module after addressing the underlying cause of the circuit high issue.

6. Is it safe to attempt to repair OBDII code B1B21 in a Mitsubishi on my own, or should I seek professional help?

Given the critical nature of airbag systems, it is generally recommended to seek professional help from a qualified technician or mechanic experienced in handling airbag-related issues.

7. Are there any recalls or service bulletins related to OBDII code B1B21 and the Right Side Curtain Squib 1 Circuit High problem in Mitsubishi vehicles?

It is advisable to check with Mitsubishi dealerships or the manufacturer's website to determine if there are any recalls or service bulletins addressing this specific OBDII code and associated airbag system concern.

8. How can I prevent OBDII code B1B21 indicating Right Side Curtain Squib 1 Circuit High in my Mitsubishi in the future?

Regular maintenance, including periodic airbag system inspections, can help prevent issues like B1B21 from occurring. Promptly addressing any warning lights or unusual symptoms is also essential.

9. Does fixing OBDII code B1B21 in a Mitsubishi require resetting the airbag system or clearing the diagnostic trouble codes (DTCs)?

After repairing the underlying cause of the Right Side Curtain Squib 1 Circuit High issue, the airbag system may need to be reset or the DTCs cleared using an OBDII scanner to extinguish the warning light on the dashboard.

10. What should I do if OBDII code B1B21 persists in my Mitsubishi even after attempting repairs on the Right Side Curtain Squib 1 Circuit High problem?

If the code persists after repairs, it is essential to reevaluate the diagnosis, check for any missed issues, or consult with a professional technician to ensure proper resolution of the OBDII code B1B21.