AutoCodes – Chevrolet – P0686 2014 Chevrolet Silverado

P0686 2014 Chevrolet Silverado Code - Engine Control Module Power Relay Control Circuit Low

Quick Answer

The powertrain relay is a normally open relay. Common causes include Weak battery, Low voltage while cranking, Faulty Engine Control Module (ECM) power relay. 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: P0686 2014 Chevrolet Silverado indicates Engine Control Module Power Relay Control Circuit Low.
Common causes: Common causes include Weak battery, Low voltage while cranking, Faulty Engine Control Module (ECM) power relay.
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 283

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 Jul 19, 2022

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code P0686 2014 Chevrolet Silverado Description

The powertrain relay is a normally open relay. The relay armature is held in the open position by spring tension. Battery positive voltage is supplied directly to the relay coil and the armature contact at all times. The Engine Control Module (ECM) supplies the ground path to the relay coil control circuit via an internal integrated circuit called an Output Driver Module (ODM). The ODM output control is configured to operate as a low side driver for the powertrain relay. The ODM for the powertrain relay also incorporates a fault detection circuit, which is continuously monitored by the ECM. When the ECM commands the powertrain relay ON, ignition 1 voltage is supplied to the ECM, and to several additional circuits.

OBDII Code P0686 2014 Chevrolet Silverado - Engine Control Module Power Relay Control Circuit Low - AutoCodes.com — P0686 2014 Chevrolet Silverado Code - Engine Control Module Power Relay Control Circuit Low

What does this mean?

What are the Possible Causes of the DTC P0686 2014 Chevrolet Silverado?

Weak battery
Low voltage while cranking
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 P0686 2014 Chevrolet Silverado?

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 P0686 2014 Chevrolet Silverado 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 P0686 2014 Chevrolet Silverado code?

Need more information on how to fix the P0686 2014 Chevrolet Silverado 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 P0686 2014 Chevrolet Silverado Code

1. What does the OBDII code P0686 mean on a 2014 Chevrolet Silverado?

P0686 indicates that the power relay control circuit for the Engine Control Module (ECM) is reading a low voltage, which could prevent the ECM from functioning properly.

2. What are the common symptoms of code P0686 in a 2014 Chevy Silverado?

Symptoms may include difficulty starting the engine, the engine stalling while driving, poor performance, or the check engine light illuminating.

3. What causes the P0686 code to appear on a 2014 Chevrolet Silverado?

Common causes include a faulty ECM power relay, damaged wiring or connectors in the relay circuit, a blown fuse, or, less commonly, a malfunctioning ECM.

4. Can I drive my 2014 Chevrolet Silverado with the P0686 code?

Driving with this code is not recommended as it can cause unpredictable stalling or starting issues, which may pose a safety risk.

5. How do I diagnose the P0686 code on my 2014 Chevy Silverado?

Begin by checking the ECM power relay and related fuses. Inspect the wiring and connectors in the relay circuit for damage, corrosion, or loose connections. Use a multimeter to test for proper voltage.

6. How can I fix the P0686 code on my 2014 Chevrolet Silverado?

Repairs may include replacing a faulty ECM power relay, repairing or replacing damaged wiring, securing loose connections, or replacing a blown fuse.

7. Is a faulty ECM a likely cause of the P0686 code?

While possible, a faulty ECM is less common. Itâ€™s more likely the issue lies with the relay, wiring, or fuse, so these should be checked first.

8. What tools are needed to troubleshoot the P0686 code?

Youâ€™ll need a multimeter to test voltage, a diagnostic scan tool to clear the code and verify repairs, and basic hand tools for accessing the relay and wiring.

9. How much does it cost to fix the P0686 code on a 2014 Chevrolet Silverado?

The cost varies depending on the root cause. Replacing an ECM power relay typically costs $20â€“$50, while wiring repairs or ECM replacement can cost significantly more.

10. Can a weak battery cause the P0686 code to appear?

Yes, a weak or failing battery can cause low voltage in the ECM power relay circuit, potentially triggering the P0686 code. Ensure the battery is in good condition.