AutoCodes – Generic – B291B

B291B Code - Content Theft Deterrent Sensor

Quick Answer

The Body Control Module (BCM) performs various communication fault detection tests to determine if a software, hardware, or communication concern exists with the ultrasonic intrusion sensor. Common causes include Faulty Content Theft Deterrent Sensor Module, Content Theft Deterrent Sensor Module harness is open or shorted, Content Theft Deterrent Sensor Module 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: B291B indicates Content Theft Deterrent Sensor.
Common causes: Common causes include Faulty Content Theft Deterrent Sensor Module, Content Theft Deterrent Sensor Module harness is open or shorted, Content Theft Deterrent Sensor Module 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 5,896

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 01, 2023

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code B291B Description

The Body Control Module (BCM) performs various communication fault detection tests to determine if a software, hardware, or communication concern exists with the ultrasonic intrusion sensor. The sensor being disconnected, a poor connection at the connector, or the vehicle battery being discharged could all cause the communication to be interrupted. This interruption stops the self-test from completing which causes Diagnostic Trouble Code (DTC) B291B. This is not because of the sensor failing, it is because of a previous or existing open connection between the sensor and the BCM. Restoring this connection and then arming the theft system will complete the test and allow the DTC to be cleared. The DTC will be set when the BCM cannot communicate with the ultrasonic intrusion sensor.

OBDII Code B291B - Content Theft Deterrent Sensor - AutoCodes.com — B291B Code - Content Theft Deterrent Sensor

What does this mean?

What are the Possible Causes of the DTC B291B?

Faulty Content Theft Deterrent Sensor Module
Content Theft Deterrent Sensor Module harness is open or shorted
Content Theft Deterrent Sensor Module circuit poor electrical connection
Faulty Body Control Module (BCM)

How to Fix the DTC B291B?

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 B291B 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 B291B code?

Need more information on how to fix the B291B code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the B291B code diagnosed by a professional: Find a repair shop in your area

Information for Specific Makes

B291B Buick — Content Theft Deterrent Sensor
B291B Cadillac — Content Theft Deterrent Sensor
B291B Chevrolet — Content Theft Deterrent Sensor
B291B GMC — Content Theft Deterrent Sensor

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 B291B Code

1. What are the common symptoms of OBDII code B291B Content Theft Deterrent Sensor?

- Common symptoms include issues with the vehicle's anti-theft system, such as the alarm not arming or disarming properly.

2. What can cause OBDII code B291B to trigger?

- This code is typically triggered by a malfunction in the content theft deterrent sensor, which is responsible for detecting unauthorized entry into the vehicle.

3. How can I diagnose the cause of OBDII code B291B?

- To diagnose this code, it is recommended to perform a thorough inspection of the content theft deterrent sensor, check its wiring and connections, and test its functionality.

4. What are the possible repair options for OBDII code B291B?

- Repair options may include replacing the content theft deterrent sensor if it is faulty, repairing damaged wiring or connections, or resetting the anti-theft system.

5. Can OBDII code B291B affect the vehicle's overall performance?

- While this code is related to the anti-theft system, it may not directly impact the vehicle's performance. However, resolving the issue promptly is important for security reasons.

6. Is it safe to continue driving with OBDII code B291B present?

- It is generally safe to drive with this code present, as long as the vehicle's anti-theft system functions properly. However, it is recommended to address the issue promptly to prevent potential security risks.

7. How can I prevent OBDII code B291B from recurring in the future?

- Regular maintenance of the content theft deterrent sensor and the anti-theft system can help prevent this code from recurring. Additionally, addressing any issues promptly can help avoid future triggers.

8. Can a DIY enthusiast repair OBDII code B291B at home?

- Depending on the root cause of the code, some DIY enthusiasts may be able to repair it at home by following diagnostic procedures and consulting the vehicle's repair manual.

9. Are there any common mistakes to avoid when dealing with OBDII code B291B?

- One common mistake to avoid is overlooking simple causes such as loose connections or sensor malfunctions, as these are often the primary reasons for this code to trigger.

10. How long does it typically take to repair OBDII code B291B?

- The repair time for this code can vary depending on the exact cause and the expertise of the person performing the repair. In general, it may take anywhere from a few minutes to a few hours to resolve the issue.