AutoCodes – Pontiac – B3857 Pontiac

B3857 Pontiac Code - Incorrect Rollover Sensor Installed

Quick Answer

The inflatable restraint vehicle Rollover Sensor (ROS) utilizes the battery power supply and a bidirectional interface circuit. Common causes include Faulty Rollover Sensor, Rollover Sensor harness is open or shorted, Rollover 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: B3857 Pontiac indicates Incorrect Rollover Sensor Installed.
Common causes: Common causes include Faulty Rollover Sensor, Rollover Sensor harness is open or shorted, Rollover 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 1,049

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 Mar 23, 2020

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code B3857 Pontiac Description

The inflatable restraint vehicle Rollover Sensor (ROS) utilizes the battery power supply and a bidirectional interface circuit. The ROS modulates current on the interface to send ID, State of Health, and deployment commands to the inflatable restraint Sensing and Diagnostic Module (SDM). When the ignition is turned on the ROS responds by performing internal diagnostics and sending an ID to the SDM. The ROS continually communicates status messages to the SDM, which determines if a fault is present in the ROS circuit. If the fault is present, the SDM will set a Diagnostic Trouble Code (DTC).

OBDII Code B3857 Pontiac - Incorrect Rollover Sensor Installed - AutoCodes.com — B3857 Pontiac Code - Incorrect Rollover Sensor Installed

What does this mean?

What are the Possible Causes of the DTC B3857 Pontiac?

Faulty Rollover Sensor
Rollover Sensor harness is open or shorted
Rollover Sensor circuit poor electrical connection
Faulty Sensing and Diagnostic Module (SDM)

How to Fix the DTC B3857 Pontiac?

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 B3857 Pontiac 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 B3857 Pontiac code?

Need more information on how to fix the B3857 Pontiac code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the B3857 Pontiac 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 B3857 Pontiac Code

1. What does the OBDII code B3857 mean on a Pontiac?

The code B3857 indicates that the incorrect rollover sensor has been installed in the vehicle, causing a mismatch with the vehicle's specifications.

2. What are the symptoms of the B3857 code?

Common symptoms include the airbag warning light being illuminated, potential deactivation of the airbag system, or error messages related to the rollover sensor.

3. What causes the B3857 code to appear?

The main cause is the installation of a rollover sensor that does not match the vehicle's specifications or communication errors between the sensor and the airbag control module.

4. Can driving with the B3857 code be dangerous?

Yes, it can be dangerous as the airbag system may not function properly in the event of a rollover or collision.

5. How do I diagnose the B3857 code?

Diagnose the code by using a scan tool to read the error, checking the part number of the installed rollover sensor, and verifying compatibility with your vehicle.

6. How can I fix the B3857 code?

Fix the issue by replacing the incorrect rollover sensor with the correct one specified for your Pontiac model.

7. Can I clear the B3857 code without replacing the sensor?

Clearing the code without replacing the sensor may temporarily remove the warning, but the issue will likely return until the correct sensor is installed.

8. Who should repair the B3857 code issue?

It is recommended to have a qualified mechanic or dealership technician handle the issue to ensure the correct sensor is installed and the airbag system is functioning properly.

9. How much does it cost to fix the B3857 code?

The cost depends on the price of the correct rollover sensor and labor charges, which can vary based on your location and vehicle model.

10. Can a faulty airbag control module cause the B3857 code?

While rare, a malfunctioning airbag control module could misinterpret the rollover sensor, but this is less common than an incorrect sensor being installed.