AutoCodes – Volkswagen – P0685 Volkswagen

P0685 Volkswagen Code - Engine Control Module Power Relay Control Circuit Open

Quick Answer

The Engine Control Module (ECM) monitors the power inputs. Common causes include Faulty Engine Control Module (ECM) power relay, ECM power relay harness is open or shorted, ECM power relay 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: P0685 Volkswagen indicates Engine Control Module Power Relay Control Circuit Open.
Common causes: Common causes include Faulty Engine Control Module (ECM) power relay, ECM power relay harness is open or shorted, ECM power relay 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 42,465

How popular is this code, among other codes? Medium

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 May 05, 2019

Description
Possible Causes
How To Fix
Tech Notes
Cost to Diagnose
FAQs
Comments
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Code P0685 Volkswagen Description

The Engine Control Module (ECM) monitors the power inputs. The ECM sets the OBDII code when the ECM remains powered up after the ignition switch has been turned OFF.

OBDII Code P0685 Volkswagen - Engine Control Module Power Relay Control Circuit Open - AutoCodes.com — P0685 Volkswagen Code - Engine Control Module Power Relay Control Circuit Open

What does this mean?

What are the Possible Causes of the DTC P0685 Volkswagen?

Faulty Engine Control Module (ECM) power relay
ECM power relay harness is open or shorted
ECM power relay circuit poor electrical connection
Blown ECM fuse
Faulty ECM

How to Fix the DTC P0685 Volkswagen?

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 does this mean?

Code Tech Notes

Check all the Engine Control Module (ECM) fuses, if the fuses are OK, then replacing the ECM relay should take care of the problem.

What is the Cost to Diagnose the Code?

Labor: 1.0

To diagnose the P0685 Volkswagen 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 P0685 Volkswagen code?

Need more information on how to fix the P0685 Volkswagen code? Get Access to Factory Service Manuals

Need Help with the Code?

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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 P0685 Volkswagen Code

1. What are the common symptoms of OBDII code P0685 in a Volkswagen?

- Common symptoms include engine stalling, difficulty starting the vehicle, and illuminated Check Engine light.

2. What does the OBDII code P0685 for a Volkswagen indicate?

- This code indicates a problem with the Engine Control Module (ECM) power relay control circuit being open or malfunctioning.

3. What are the possible causes of the P0685 code in a Volkswagen?

- Possible causes include a faulty ECM power relay, damaged wiring or connectors in the power relay circuit, or a defective ECM.

4. How can I diagnose the cause of the P0685 code in my Volkswagen?

- You can diagnose the issue by checking the power relay and related wiring for any visible damage, testing the relay for proper functionality, and using a multimeter to check for continuity in the circuit.

5. Can I drive my Volkswagen with the P0685 code present?

- It is not recommended to drive your vehicle with the P0685 code present, as it can lead to performance issues and potential further damage to the engine control system.

6. How can I repair the OBDII code P0685 in my Volkswagen?

- Repair options include replacing the ECM power relay, repairing damaged wiring or connectors, or replacing the Engine Control Module if necessary.

7. Is it possible to reset the P0685 code in a Volkswagen without fixing the underlying issue?

- While you can clear the code with an OBDII scanner, it will likely reappear until the root cause of the problem is addressed.

8. Can a DIY enthusiast fix the P0685 code in a Volkswagen?

- Depending on your skill level and access to tools, a DIY enthusiast may be able to diagnose and fix the issue, especially if it involves replacing a relay or repairing wiring.

9. Will the P0685 code cause any long-term damage to my Volkswagen?

- Ignoring the P0685 code can potentially lead to further damage to the engine control system, so it's best to address the issue promptly to prevent any long-term damage.

10. How much can I expect to pay to repair the P0685 code in my Volkswagen?

- The cost of repairing the P0685 code can vary depending on the specific cause of the issue, but it may range from $100 to $500 or more, including parts and labor.