AutoCodes – Generic – B1796

B1796 Code - Sleep Operation Failure of Occupant Classification ECU

Quick Answer

During sleep mode, the Occupant Detection ECU monitors the condition of each sensor while the ignition switch is off. Common causes include Faulty Occupant Detection ECU, Occupant Detection ECU harness is open or shorted, Occupant Detection ECU 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: B1796 indicates Sleep Operation Failure of Occupant Classification ECU.
Common causes: Common causes include Faulty Occupant Detection ECU, Occupant Detection ECU harness is open or shorted, Occupant Detection ECU 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 5,986

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 Oct 20, 2022

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code B1796 Description

During sleep mode, the Occupant Detection ECU monitors the condition of each sensor while the ignition switch is off. In this mode, if the Occupant Detection ECU detects an internal malfunction, the Diagnostic Trouble Code (DTC) B1796 is stored.

OBDII Code B1796 - Sleep Operation Failure of Occupant Classification ECU - AutoCodes.com — B1796 Code - Sleep Operation Failure of Occupant Classification ECU

What does this mean?

What are the Possible Causes of the DTC B1796?

Faulty Occupant Detection ECU
Occupant Detection ECU harness is open or shorted
Occupant Detection ECU circuit poor electrical connection

How to Fix the DTC B1796?

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 B1796 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 B1796 code?

Need more information on how to fix the B1796 code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the B1796 code diagnosed by a professional: Find a repair shop in your area

Information for Specific Makes

B1796 Lexus — Sleep Operation Failure of Occupant Classification ECU
B1796 Scion — Sleep Operation Failure of Occupant Classification ECU
B1796 Toyota — Sleep Operation Failure of Occupant Classification ECU

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 B1796 Code

1. What are the common symptoms of OBDII code B1796 (Sleep Operation Failure of Occupant Classification ECU)?

- The common symptoms include the airbag warning light illuminating on the dashboard and potential issues with the vehicle's occupant classification system.

2. What can cause the OBDII code B1796 to trigger?

- The code B1796 is typically triggered by a malfunction in the occupant classification electronic control unit (ECU) related to sleep operation failure.

3. How serious is the OBDII code B1796 issue?

- The issue indicated by code B1796 is related to the occupant classification system, which plays a crucial role in the proper functioning of the vehicle's airbag system. It is important to address this issue promptly to ensure the safety features work as intended.

4. Can I continue driving my vehicle with the OBDII code B1796 present?

- While the vehicle may still be operable with the code present, it is not recommended to ignore the issue, as it may affect the proper functioning of the airbag system in the event of a collision.

5. How can I diagnose the cause of the OBDII code B1796?

- Diagnosing the cause of code B1796 typically involves using a diagnostic scanner to retrieve the fault codes, followed by further inspection of the occupant classification ECU and related components.

6. What are the possible repair options for OBDII code B1796?

- Repair options for code B1796 may include checking and repairing wiring connections, replacing faulty sensors or components, or reprogramming the occupant classification ECU.

7. Can I reset the OBDII code B1796 without fixing the underlying issue?

- While you can clear the code temporarily, it is important to address the underlying issue causing the code to prevent it from reoccurring and ensure the proper functioning of the occupant classification system.

8. Is it possible to repair the occupant classification ECU myself?

- Repairing the occupant classification ECU may require specialized knowledge and tools, so it is recommended to consult a professional mechanic or dealership for proper diagnosis and repair.

9. How much does it cost to repair the OBDII code B1796 issue?

- The cost of repairing the OBDII code B1796 can vary depending on the specific cause of the issue, parts needed for replacement, and labor costs. It is advisable to obtain quotes from different repair shops for an accurate estimate.

10. Are there any recalls or technical service bulletins related to OBDII code B1796?

- It is advisable to check with the vehicle manufacturer or authorized dealerships for any recalls or technical service bulletins related to code B1796, as they may provide information on known issues and recommended solutions.