AutoCodes – Mercury – B0091 Mercury

B0091 Mercury Code - Left Side Restraints Sensor 1

Quick Answer

The Restraints Control Module (RCM) monitors all of Supplemental Restraint System (SRS) device connections. Common causes include Faulty Left Side Restraints Sensor 1, Left Side Restraints Sensor 1 harness is open or shorted, Left Side Restraints Sensor 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: B0091 Mercury indicates Left Side Restraints Sensor 1.
Common causes: Common causes include Faulty Left Side Restraints Sensor 1, Left Side Restraints Sensor 1 harness is open or shorted, Left Side Restraints Sensor 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 2,772

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 Jun 14, 2020

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code B0091 Mercury Description

The Restraints Control Module (RCM) monitors all of Supplemental Restraint System (SRS) device connections. If the RCM detects a connection or device connected that is not stored in memory or is not configured for the component, the RCM will set a Diagnostic Trouble Code (DTC) and send a message to the Instrument Panel Cluster (IPC) to illuminate air bag warning indicator.

OBDII Code B0091 Mercury - Left Side Restraints Sensor 1 - AutoCodes.com — B0091 Mercury Code - Left Side Restraints Sensor 1

What does this mean?

What are the Possible Causes of the DTC B0091 Mercury?

Faulty Left Side Restraints Sensor 1
Left Side Restraints Sensor 1 harness is open or shorted
Left Side Restraints Sensor 1 circuit poor electrical connection

How to Fix the DTC B0091 Mercury?

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 B0091 Mercury 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 B0091 Mercury code?

Need more information on how to fix the B0091 Mercury code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the B0091 Mercury 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 B0091 Mercury Code

1. What are the common symptoms of OBDII code B0091 in a Mercury related to the Left Side Restraints Sensor 1?

The common symptoms include the airbag warning light illuminating on the dashboard, potential non-deployment of the airbags during a collision, and diagnostic trouble codes stored in the vehicle's system.

2. What could be causing the OBDII code B0091 in a Mercury related to the Left Side Restraints Sensor 1?

The code B0091 typically indicates a fault with the left side impact sensor or its circuitry, such as a malfunctioning sensor, wiring issues, or a poor connection.

3. How can I diagnose the OBDII code B0091 in my Mercury for the Left Side Restraints Sensor 1?

Diagnosing this code usually involves using a scan tool to retrieve the specific fault codes, checking the wiring and connections associated with the left side impact sensor, and testing the sensor itself for proper functioning.

4. Can I still drive my Mercury with the OBDII code B0091 related to the Left Side Restraints Sensor 1?

It is not recommended to drive the vehicle with an active airbag system fault code like B0091, as it could potentially compromise the safety of the airbag system in the event of a collision.

5. How can I repair the OBDII code B0091 in my Mercury for the Left Side Restraints Sensor 1?

Repairing this code may involve replacing the left side impact sensor if it is faulty, repairing any damaged wiring or connections, and clearing the diagnostic trouble codes from the vehicle's system.

6. Are there any safety precautions to consider when working on the Left Side Restraints Sensor 1 related to OBDII code B0091 in a Mercury?

When working on the airbag system, it is crucial to disconnect the vehicle's battery and wait for a specified amount of time to discharge any stored energy to avoid accidental deployment of the airbags.

7. Can a DIY enthusiast fix the OBDII code B0091 related to the Left Side Restraints Sensor 1 in a Mercury?

While some DIY enthusiasts may have the skills to diagnose and repair issues related to the airbag system, it is recommended to consult a professional technician or mechanic due to the critical nature of the airbag system.

8. How much does it cost to repair the OBDII code B0091 in a Mercury for the Left Side Restraints Sensor 1?

The cost of repairing this code can vary depending on the specific issue causing the fault, the labor rates of the repair shop, and the cost of any replacement parts needed, so it is advisable to obtain a professional diagnosis and estimate.

9. Can a disconnected or faulty Left Side Restraints Sensor 1 impact other safety features in the Mercury?

Yes, a malfunctioning or disconnected left side impact sensor can potentially impact the overall functionality of the airbag system and other safety features designed to deploy in the event of a collision.

10. How often should I have the airbag system in my Mercury inspected to prevent OBDII code B0091 related to the Left Side Restraints Sensor 1?

Regular maintenance and inspection of the airbag system, including the impact sensors, wiring, and connections, are recommended as part of a comprehensive vehicle safety check or service schedule to help prevent issues like code B0091 from occurring.