AutoCodes – Mitsubishi – B1B78 Mitsubishi

B1B78 Mitsubishi Code - Passenger Seat Weight Sensor 3 Left Front Performance

Quick Answer

During the Occupant Classification Module (OCM) system verification test if the module detects that the sensor input is less than 1.4 volts or greater than 3.6 volts. Common causes include Faulty Left Front Passenger Seat Weight Sensor, Left Front Passenger Seat Weight Sensor harness is open or shorted, Left Front Passenger Seat Weight Sensor 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: B1B78 Mitsubishi indicates Passenger Seat Weight Sensor 3 Left Front Performance.
Common causes: Common causes include Faulty Left Front Passenger Seat Weight Sensor, Left Front Passenger Seat Weight Sensor harness is open or shorted, Left Front Passenger Seat Weight Sensor 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 881

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 22, 2019

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code B1B78 Mitsubishi Description

During the Occupant Classification Module (OCM) system verification test if the module detects that the sensor input is less than 1.4 volts or greater than 3.6 volts. During auto zero: if the module detects that the sensor input is less than 1 volt or greater than 4 volts.

OBDII Code B1B78 Mitsubishi - Passenger Seat Weight Sensor 3 Left Front Performance - AutoCodes.com — B1B78 Mitsubishi Code - Passenger Seat Weight Sensor 3 Left Front Performance

What does this mean?

What are the Possible Causes of the DTC B1B78 Mitsubishi?

Faulty Left Front Passenger Seat Weight Sensor
Left Front Passenger Seat Weight Sensor harness is open or shorted
Left Front Passenger Seat Weight Sensor circuit poor electrical connection
Faulty Occupant Classification Module (OCM)

How to Fix the DTC B1B78 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 B1B78 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 B1B78 Mitsubishi code?

Need more information on how to fix the B1B78 Mitsubishi code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the B1B78 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 B1B78 Mitsubishi Code

1. What does OBDII code B1B78 for Mitsubishi indicate?

The code B1B78 specifically refers to the Passenger Seat Weight Sensor 3 Left Front Performance issue in a Mitsubishi vehicle.

2. What are the common symptoms of a B1B78 code in a Mitsubishi?

Common symptoms of the B1B78 code may include the airbag warning light illuminating on the dashboard and potential issues with the passenger seat belt reminder system.

3. What can cause the B1B78 code to trigger in a Mitsubishi?

The B1B78 code is typically triggered by a fault in the passenger seat weight sensor, which measures the weight of the occupant to determine if the airbag should be activated.

4. How serious is the B1B78 code in a Mitsubishi?

While the B1B78 code may not directly affect the drivability of the vehicle, it is important to address this issue promptly to ensure the proper functioning of the airbag system in the event of a collision.

5. Can I continue driving my Mitsubishi with a B1B78 code?

It is not recommended to drive the vehicle with an active B1B78 code, as it may indicate a problem with the airbag system, which is crucial for occupant safety in the event of an accident.

6. How can I diagnose and repair a B1B78 code in my Mitsubishi?

Diagnosing and repairing a B1B78 code usually involves checking the passenger seat weight sensor and its wiring for any faults, replacing the sensor if necessary, and resetting the fault code with a diagnostic tool.

7. Can I reset the B1B78 code in my Mitsubishi without fixing the issue?

Resetting the B1B78 code without addressing the underlying problem with the passenger seat weight sensor is not recommended, as the issue may persist and compromise the safety features of the vehicle.

8. Is the repair for a B1B78 code in a Mitsubishi expensive?

The cost of repairing a B1B78 code in a Mitsubishi can vary depending on the extent of the issue and the specific components that need to be replaced. It is advisable to consult a professional mechanic for an accurate estimate.

9. Are there any DIY tips for troubleshooting a B1B78 code in a Mitsubishi?

While basic troubleshooting steps like checking the sensor connections and wiring can be done by DIY enthusiasts, diagnosing and repairing the B1B78 code may require specialized tools and expertise best handled by a professional mechanic.

10. How often does the B1B78 code occur in Mitsubishi vehicles?

The occurrence of the B1B78 code in Mitsubishi vehicles can vary, but it is a relatively common issue associated with the passenger seat weight sensor system, especially in older models or vehicles that have been involved in accidents.