AutoCodes – Generic – B0685

B0685 Code - Security System Indicator Circuit Short to Ground

Quick Answer

The security LED is controlled by the Body Control Module (BCM) based on commands from the content theft deterrent system. Common causes include Faulty Light/Sunload Ambient Sensor, Light/Sunload Ambient Sensor harness is open or shorted, Light/Sunload Ambient 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: B0685 indicates Security System Indicator Circuit Short to Ground.
Common causes: Common causes include Faulty Light/Sunload Ambient Sensor, Light/Sunload Ambient Sensor harness is open or shorted, Light/Sunload Ambient 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 1,389

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 Nov 16, 2022

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code B0685 Description

The security LED is controlled by the Body Control Module (BCM) based on commands from the content theft deterrent system. The security LED is located in the dash as part of the ambient light sensor and is supplied ground at all times. When the content theft deterrent system requests the LED be commanded ON, the BCM applies voltage to the security indicator control circuit, illuminating the LED.

OBDII Code B0685 - Security System Indicator Circuit Short to Ground - AutoCodes.com — B0685 Code - Security System Indicator Circuit Short to Ground

What does this mean?

What are the Possible Causes of the DTC B0685?

Faulty Light/Sunload Ambient Sensor
Light/Sunload Ambient Sensor harness is open or shorted
Light/Sunload Ambient Sensor circuit poor electrical connection
Faulty Body Control Module (BCM)

How to Fix the DTC B0685?

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 B0685 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 B0685 code?

Need more information on how to fix the B0685 code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the B0685 code diagnosed by a professional: Find a repair shop in your area

Information for Specific Makes

B0685 Buick — Security System Indicator Circuit Short to Ground
B0685 Cadillac — Security System Indicator Circuit Short to Ground
B0685 Chevrolet — Security System Indicator Circuit Short to Ground
B0685 GMC — Security System Indicator Circuit Short to Ground

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 B0685 Code

1. What are the common symptoms of OBDII code B0685?

- Common symptoms include the security system indicator light staying on constantly or flashing erratically, and the vehicle not starting or experiencing intermittent starting issues.

2. What can cause the Security System Indicator Circuit to short to ground?

- The circuit can short to ground due to damaged wiring, a faulty security system indicator light, or a malfunctioning security system control module.

3. How can I diagnose the cause of OBDII code B0685?

- To diagnose the issue, you can perform a visual inspection of the wiring, test the security system indicator light, and use a scan tool to check for any related trouble codes in the security system control module.

4. Can a DIYer repair the Security System Indicator Circuit short to ground issue?

- While some simple wiring repairs can be done by DIYers, diagnosing and repairing complex issues related to the security system may require professional diagnostic equipment and expertise.

5. What are the potential risks of ignoring OBDII code B0685?

- Ignoring the code can lead to security system malfunctions, potential immobilization of the vehicle, and issues with starting the vehicle reliably.

6. Is it safe to drive with OBDII code B0685 present?

- It is not recommended to drive with the code present, as the security system may not function properly, leading to potential security risks and starting problems.

7. How much does it typically cost to repair OBDII code B0685?

- Repair costs can vary depending on the underlying cause of the issue, but they can range from a simple wiring repair to replacing the security system control module, potentially costing a few hundred to a thousand dollars.

8. Can a dead battery cause OBDII code B0685 to appear?

- A dead or weak battery can sometimes trigger false codes related to the security system, including B0685. It's advised to ensure the battery is in good condition before diagnosing the issue further.

9. Are there any preventive measures to avoid OBDII code B0685 in the future?

- Regularly inspecting the security system wiring, ensuring proper maintenance of the security system components, and addressing any warning signs promptly can help prevent the recurrence of this code.

10. How long does it typically take to repair OBDII code B0685?

- The repair time can vary based on the complexity of the issue and the availability of parts. Simple wiring repairs may take a few hours, while more involved repairs can take a day or longer at a repair shop.