AutoCodes – Generic – C1686

C1686 Code - 4WAS Main Control Unit

Quick Answer

It transmits the value calculated by 4 Wheel Active Steer (4WAS) Main Control Unit to 4WAS front control unit with 4WAS communication line (line for 4WAS system). Common causes include Faulty 4 Wheel Active Steer (4WAS) Main Control Unit, 4 Wheel Active Steer (4WAS) Main Control Unit harness is open or shorted, 4 Wheel Active Steer (4WAS) Main Control Unit 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: C1686 indicates 4WAS Main Control Unit.
Common causes: Common causes include Faulty 4 Wheel Active Steer (4WAS) Main Control Unit, 4 Wheel Active Steer (4WAS) Main Control Unit harness is open or shorted, 4 Wheel Active Steer (4WAS) Main Control Unit 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 4,621

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 17, 2020

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code C1686 Description

It transmits the value calculated by 4 Wheel Active Steer (4WAS) Main Control Unit to 4WAS front control unit with 4WAS communication line (line for 4WAS system). 4WAS front control unit controls 4WAS front actuator according to the received command value.

OBDII Code C1686 - 4WAS Main Control Unit - AutoCodes.com — C1686 Code - 4WAS Main Control Unit

What does this mean?

What are the Possible Causes of the DTC C1686?

Faulty 4 Wheel Active Steer (4WAS) Main Control Unit
4 Wheel Active Steer (4WAS) Main Control Unit harness is open or shorted
4 Wheel Active Steer (4WAS) Main Control Unit circuit poor electrical connection

How to Fix the DTC C1686?

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 C1686 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 C1686 code?

Need more information on how to fix the C1686 code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the C1686 code diagnosed by a professional: Find a repair shop in your area

Information for Specific Makes

C1686 Infiniti — 4WAS Main Control Unit
C1686 Lexus — Driver Side Camera Video Sync Signal Malfunction
C1686 Nissan — 4WAS Main Control Unit
C1686 Toyota — Driver Side Camera Video Sync Signal Malfunction

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 C1686 Code

1. What does the OBDII code C1686 indicate?

The code C1686 indicates a problem with the "4WAS Main Control Unit" in a vehicle's Four-Wheel Active Steering system, suggesting a malfunction within the control unit itself.

2. What are common symptoms of the C1686 error code?

Symptoms include unusual steering behavior, warning lights on the dashboard, particularly for the steering system, and possibly a complete loss of active steering features.

3. What could cause the C1686 error code to appear?

Possible causes include electrical issues like faulty wiring or connections, a defective 4WAS main control unit, or software issues needing updates or reconfiguration.

4. How is the C1686 error code diagnosed?

Diagnosis typically involves using a specialized scanner to read the fault code from the vehicleâ€™s OBD system, followed by a thorough inspection of the 4WAS system, including electrical connections and the control unit.

5. What steps are involved in repairing an issue related to code C1686?

Repair steps may include checking and repairing any faulty electrical connections, replacing the defective 4WAS main control unit, or updating the system's software.

6. Can I drive my car with the C1686 code active?

While you might be able to drive the vehicle, it is not recommended as steering control might be compromised, potentially leading to safety issues.

7. How urgent is it to address a C1686 error code?

It is fairly urgent to address this issue due to the potential impact on steering functionality and overall vehicle safety.

8. What vehicles are most likely to encounter the C1686 code?

This code is more commonly found in vehicles equipped with advanced steering systems such as those with Four-Wheel Active Steering (4WAS), primarily seen in higher-end models and performance vehicles.

9. Are there any common misdiagnoses associated with the C1686 code?

Yes, sometimes issues in the electrical system or other steering components can be mistakenly attributed to the 4WAS main control unit, leading to unnecessary replacements.

10. How can future occurrences of the C1686 code be prevented?

Regular maintenance and inspections of the vehicleâ€™s steering system are essential. Ensuring software updates are applied and keeping electrical connections clean and secure can help prevent this issue.