AutoCodes – Chevrolet – P0686 2016 Chevrolet Silverado

P0686 2016 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 2016 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 295

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 2016 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 2016 Chevrolet Silverado - Engine Control Module Power Relay Control Circuit Low - AutoCodes.com — P0686 2016 Chevrolet Silverado Code - Engine Control Module Power Relay Control Circuit Low

What does this mean?

What are the Possible Causes of the DTC P0686 2016 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 2016 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 2016 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 2016 Chevrolet Silverado code?

Need more information on how to fix the P0686 2016 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 2016 Chevrolet Silverado Code

1. What does OBDII code P0686 mean on a 2016 Chevrolet Silverado?

P0686 indicates a low voltage condition in the Engine Control Module (ECM) Power Relay Control Circuit, meaning the ECM may not be receiving proper power to function correctly.

2. What are the symptoms of code P0686 in a 2016 Chevrolet Silverado?

Common symptoms include difficulty starting the engine, engine stalling, reduced performance, or the vehicle failing to start altogether.

3. What causes the P0686 code in a 2016 Chevrolet Silverado?

Possible causes include a faulty ECM power relay, corroded or damaged wiring, a blown fuse, or a malfunctioning ECM.

4. How do you diagnose the P0686 code on a 2016 Chevrolet Silverado?

Diagnosis involves checking the ECM power relay, inspecting fuses, testing the wiring and connectors for damage, and verifying proper voltage levels with a multimeter.

5. Can driving with a P0686 code damage my 2016 Chevrolet Silverado?

Yes, driving with this code may lead to further electrical issues or cause the vehicle to stall unexpectedly, posing potential safety risks.

6. How do you fix the P0686 code on a 2016 Chevrolet Silverado?

Repairs may include replacing a faulty ECM power relay, repairing damaged wiring, replacing blown fuses, or, in rare cases, replacing the ECM.

7. Is the P0686 code related to other trouble codes on a 2016 Chevrolet Silverado?

Yes, this code can sometimes appear alongside other electrical or power-related codes, such as P0685 or P0687, which also involve the ECM power relay circuit.

8. How much does it cost to fix the P0686 code on a 2016 Chevrolet Silverado?

Repair costs can vary but typically range from $50 to $200 for parts and labor, depending on whether the issue lies with the relay, wiring, or other components.

9. Can I clear the P0686 code without fixing the problem?

Clearing the code without addressing the underlying issue will only temporarily remove the code; the problem will persist and the code will likely return.

10. Should I replace the ECM if I get a P0686 code on my 2016 Chevrolet Silverado?

The ECM should only be replaced after all other potential issues, such as the power relay and wiring, have been thoroughly tested and ruled out as the cause.