AutoCodes – Generic – B2709

B2709 Code - Rear Sonar Sensor Left Inner Harness

Quick Answer

With power and ground supplied to the sonar sensors, the sonar sensors transmit an ultrasonic signal. Common causes include Faulty Rear Sonar Sensor Left Inner, Rear Sonar Sensor Left Inner harness is open or shorted, Rear Sonar Sensor Left Inner 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: B2709 indicates Rear Sonar Sensor Left Inner Harness.
Common causes: Common causes include Faulty Rear Sonar Sensor Left Inner, Rear Sonar Sensor Left Inner harness is open or shorted, Rear Sonar Sensor Left Inner 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 1,075

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 Jan 25, 2020

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code B2709 Description

With power and ground supplied to the sonar sensors, the sonar sensors transmit an ultrasonic signal. This signal is reflected back to the sensor by objects large enough and close enough to be detected. The sonar sensors measure the time from the transmitted signal to the time the signal is reflected back and send this information to the Sonar Control Unit. The Sonar Control Unit sets the Diagnostic Trouble Code (DTC) when the Rear Sonar Sensor Left Inner is out of factory specifications.

OBDII Code B2709 - Rear Sonar Sensor Left Inner Harness - AutoCodes.com — B2709 Code - Rear Sonar Sensor Left Inner Harness

What does this mean?

What are the Possible Causes of the DTC B2709?

Faulty Rear Sonar Sensor Left Inner
Rear Sonar Sensor Left Inner harness is open or shorted
Rear Sonar Sensor Left Inner circuit poor electrical connection
Faulty Sonar Control Unit

How to Fix the DTC B2709?

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 B2709 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 B2709 code?

Need more information on how to fix the B2709 code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the B2709 code diagnosed by a professional: Find a repair shop in your area

Information for Specific Makes

B2709 Infiniti — Rear Sonar Sensor Left Inner Harness
B2709 Nissan — Rear Sonar Sensor Left Inner Harness

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 B2709 Code

1. What does the OBDII code B2709 mean?

The B2709 code indicates an issue with the rear sonar sensor left inner harness, often related to a communication or electrical fault between the sensor and the vehicle's control module.

2. What are the common symptoms of the B2709 code?

Common symptoms include a malfunctioning rear parking assist system, warning lights on the dashboard, or the system failing to detect nearby obstacles.

3. What causes the B2709 code to appear?

This code is typically caused by a damaged or disconnected wiring harness, a faulty rear sonar sensor, or corrosion or debris on the sensor or its connectors.

4. How can I diagnose the B2709 code?

Diagnose by visually inspecting the rear sonar sensor and its wiring for damage, testing the harness for continuity, and using a scan tool to check for related codes or sensor data.

5. Can I drive with the B2709 code active?

Yes, you can drive with this code active, but your parking assist system may not function properly, increasing the risk of collisions during parking maneuvers.

6. How is the B2709 code fixed?

Common fixes include repairing or replacing the damaged wiring harness, cleaning or replacing the rear sonar sensor, or ensuring all connectors are properly secured.

7. How much does it cost to fix the B2709 code?

Repair costs can range from $50 to $300, depending on whether you need to repair the harness, replace the sensor, or perform additional diagnostics.

8. Can I fix the B2709 code myself?

If you have basic mechanical skills, you can inspect and clean the sensor, check for loose connections, and repair minor wiring issues. For more advanced repairs, professional help may be needed.

9. Does weather affect the B2709 code?

Yes, extreme weather conditions like heavy rain or snow can cause water intrusion or debris buildup around the sensor, potentially triggering the code.

10. What tools are needed to diagnose the B2709 code?

Youâ€™ll need an OBDII scan tool, a multimeter for electrical testing, and possibly basic hand tools for accessing and examining the sensor and harness.