AutoCodes – Generic – B1B78

B1B78 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 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.

Save to My Repairs My Repairs

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

Code Popularity 1,375

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 Aug 22, 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 B1B78 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 - Passenger Seat Weight Sensor 3 Left Front Performance - AutoCodes.com — B1B78 Code - Passenger Seat Weight Sensor 3 Left Front Performance

What does this mean?

What are the Possible Causes of the DTC B1B78?

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?

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 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 code?

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

Need Help with the Code?

Get the B1B78 code diagnosed by a professional: Find a repair shop in your area

Information for Specific Makes

B1B78 Chrysler — Passenger Seat Weight Sensor 3 Left Front Performance
B1B78 Dodge — Passenger Seat Weight Sensor 3 Left Front Performance
B1B78 Jeep — Passenger Seat Weight Sensor 3 Left Front Performance
B1B78 Mitsubishi — Passenger Seat Weight Sensor 3 Left Front Performance
B1B78 RAM — Passenger Seat Weight Sensor 3 Left Front Performance

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 Code

1. What are the common symptoms of OBDII code B1B78 related to the Passenger Seat Weight Sensor 3 Left Front Performance?

The common symptoms include the airbag warning light illuminating on the dashboard and a potential message indicating an issue with the passenger seat airbag system.

2. What are the possible causes of OBDII code B1B78 for the Passenger Seat Weight Sensor 3 Left Front Performance?

Possible causes include a malfunctioning weight sensor in the passenger seat, damaged wiring or connectors, or issues with the airbag control module.

3. How can I diagnose the issue related to OBDII code B1B78 for the Passenger Seat Weight Sensor 3 Left Front Performance?

Diagnosis typically involves using a professional OBDII scanner to retrieve the specific fault code, checking the passenger seat weight sensor and related components for damage, and inspecting the wiring for any visible issues.

4. Can I still drive my vehicle with OBDII code B1B78 triggered for the Passenger Seat Weight Sensor 3 Left Front Performance?

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

5. How can I reset OBDII code B1B78 for the Passenger Seat Weight Sensor 3 Left Front Performance?

Resetting the code typically involves fixing the underlying issue first, which may include repairing or replacing the faulty components, and then using an OBDII scanner to clear the code from the system.

6. Is it safe to attempt to repair OBDII code B1B78 related to the Passenger Seat Weight Sensor 3 Left Front Performance on my own?

While some basic troubleshooting steps can be taken, it is recommended to seek professional help when dealing with airbag system issues to ensure proper diagnosis and repair, as they are critical safety components.

7. Are there any recalls or technical service bulletins related to OBDII code B1B78 for the Passenger Seat Weight Sensor 3 Left Front Performance?

It is advisable to check with the vehicle manufacturer or authorized dealerships for any recalls or technical service bulletins related to this specific fault code, as they may offer solutions or guidance for repairs.

8. What should I do if OBDII code B1B78 persists after attempting repairs on the Passenger Seat Weight Sensor 3 Left Front Performance?

If the code persists after attempted repairs, it is best to consult a professional mechanic or dealership with experience in diagnosing and repairing airbag system faults for a more in-depth inspection and resolution.

9. Can a faulty Passenger Seat Weight Sensor 3 Left Front impact the overall safety of the vehicle?

Yes, a malfunctioning passenger seat weight sensor can impact the proper deployment of the passenger seat airbag in the event of a collision, potentially compromising the safety of the vehicle occupants.

10. How much does it typically cost to repair OBDII code B1B78 associated with the Passenger Seat Weight Sensor 3 Left Front Performance?

The cost of repair can vary depending on the extent of the issue, the need for replacement parts, and labor costs. It is advisable to obtain quotes from different repair shops or dealerships to compare prices before proceeding with the repair.