AutoCodes – Generic – C1685

C1685 Code - 4WAS Main Control Unit Communication

Quick Answer

The 4 Wheel Active Steer (4WAS) front control unit and 4WAS main control unit transmit/receive information to/from each other for optimum control of the 4WAS system with the specified 4WAS system line (4WAS communication line) between 4WAS Front Control Unit and 4WAS Main Control Unit. Common causes include Faulty 4 Wheel Active Steer (4WAS) Main Control Unit, Faulty 4 Wheel Active Steer (4WAS) Front Control Unit. 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: C1685 indicates 4WAS Main Control Unit Communication.
Common causes: Common causes include Faulty 4 Wheel Active Steer (4WAS) Main Control Unit, Faulty 4 Wheel Active Steer (4WAS) Front Control Unit.
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 890

How popular is this code, among other codes? Low

Repair Importance Level

Urgent (Diagnose now) (3 / 3)

Repair Difficulty Level

Advanced (Pro) (3 / 3)

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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 C1685 Description

OBDII Code C1685 - 4WAS Main Control Unit Communication - AutoCodes.com — C1685 Code - 4WAS Main Control Unit Communication

What does this mean?

What are the Possible Causes of the DTC C1685?

Faulty 4 Wheel Active Steer (4WAS) Main Control Unit
Faulty 4 Wheel Active Steer (4WAS) Front Control Unit

How to Fix the DTC C1685?

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 C1685 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 C1685 code?

Need more information on how to fix the C1685 code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the C1685 code diagnosed by a professional: Find a repair shop in your area

Information for Specific Makes

C1685 Infiniti — 4WAS Main Control Unit Communication
C1685 Nissan — 4WAS Main Control Unit Communication

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 C1685 Code

1. What does the OBDII code C1685 mean?

C1685 indicates a communication issue between the Four-Wheel Active Steering (4WAS) main control unit and other modules in the vehicle.

2. What are the common symptoms of the C1685 code?

Symptoms include the 4WAS system malfunction warning light, reduced steering responsiveness, or complete deactivation of the 4WAS system.

3. What causes the C1685 code to appear?

Common causes include faulty wiring, a damaged 4WAS control unit, corroded connectors, or a loss of communication due to a malfunctioning CAN bus network.

4. Can I still drive my vehicle with the C1685 code?

You can drive the vehicle, but the 4WAS system may not function properly, which could affect handling and steering in certain conditions.

5. How do I diagnose the C1685 code?

Use an advanced scan tool to check for communication errors in the CAN bus network, inspect the wiring and connectors for damage, and test the 4WAS control unit for proper operation.

6. How is the C1685 code fixed?

Repairs may include replacing damaged wiring, cleaning or replacing corroded connectors, or replacing the 4WAS main control unit if itâ€™s faulty.

7. Is the C1685 code specific to certain vehicles?

Yes, the C1685 code is typically found in vehicles equipped with Four-Wheel Active Steering systems, and its specifics may vary by manufacturer.

8. Can a low battery cause the C1685 code?

Yes, a low or failing battery can disrupt communication between control modules and trigger the C1685 code.

9. How much does it cost to repair the C1685 code?

Repair costs can vary depending on the issue, ranging from $50 for a simple wiring fix to over $1,000 if the 4WAS control unit needs replacement.

10. How can I prevent the C1685 code from recurring?

Regularly inspect the electrical system for damaged wiring or corrosion, keep the battery in good condition, and ensure proper maintenance of the 4WAS system.