AutoCodes – Pontiac – B3856 Pontiac

B3856 Pontiac Code - Discard Rollover Sensor

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: B3856 Pontiac indicates Discard Rollover Sensor.
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 551

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 Mar 23, 2020

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code B3856 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 B3856 Pontiac - Discard Rollover Sensor - AutoCodes.com — B3856 Pontiac Code - Discard Rollover Sensor

What does this mean?

What are the Possible Causes of the DTC B3856 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 B3856 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 B3856 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 B3856 Pontiac code?

Need more information on how to fix the B3856 Pontiac code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the B3856 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 B3856 Pontiac Code

1. What are the common symptoms of OBDII code B3856 (Pontiac) related to the Discard Rollover Sensor?

The common symptoms include the airbag warning light being illuminated on the dashboard and a potential indication of a malfunction in the rollover sensor system.

2. What are the possible causes of OBDII code B3856 (Pontiac) related to the Discard Rollover Sensor?

The code B3856 may be triggered due to a faulty rollover sensor, damaged wiring or connectors in the sensor circuit, or issues with the airbag control module.

3. How can I diagnose the OBDII code B3856 (Pontiac) related to the Discard Rollover Sensor?

Diagnosing this code involves using a diagnostic scanner to retrieve the specific fault code, inspecting the rollover sensor and its connections for any visible damage, and testing the sensor's functionality according to the manufacturer's specifications.

4. Can I continue driving my Pontiac with the OBDII code B3856 (Discard Rollover Sensor) illuminated?

It is not recommended to drive the vehicle with the airbag warning light on as it indicates a potential safety issue with the rollover sensor system. Prompt inspection and repairs are advised.

5. How can I repair OBDII code B3856 (Pontiac) related to the Discard Rollover Sensor?

Repairing this code typically involves replacing the faulty rollover sensor, repairing any damaged wiring or connectors in the sensor circuit, and clearing the fault code from the vehicle's system using a diagnostic tool.

6. Are there any safety concerns associated with OBDII code B3856 (Pontiac) related to the Discard Rollover Sensor?

Yes, the rollover sensor is a crucial component of the vehicle's safety system, and driving with a malfunctioning sensor may compromise the proper deployment of the airbags in the event of a rollover accident.

7. Is it possible to reset the OBDII code B3856 (Pontiac) related to the Discard Rollover Sensor without repairs?

While you can clear the fault code temporarily using a diagnostic scanner, it is important to address the underlying issue causing the code to prevent potential safety risks.

8. Can a DIY enthusiast perform the repairs for OBDII code B3856 (Pontiac) related to the Discard Rollover Sensor?

Depending on their skill level and access to proper tools, a DIY enthusiast may be able to replace the rollover sensor or repair wiring issues. However, for safety reasons, it is recommended to consult a professional mechanic.

9. How much does it typically cost to repair OBDII code B3856 (Pontiac) related to the Discard Rollover Sensor?

The cost of repairs can vary based on the specific issue causing the code, the labor rates in your area, and the price of replacement parts. It is best to obtain quotes from local mechanics or dealerships for an accurate estimate.

10. Are there any recalls or technical service bulletins related to OBDII code B3856 (Pontiac) and the Discard Rollover Sensor?

It is advisable to check with the manufacturer or authorized service centers for any recalls or technical service bulletins related to this specific OBDII code to see if your vehicle is affected by any known issues.