AutoCodes – Chevrolet – P0686 2015 Chevrolet Silverado

P0686 2015 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 2015 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 298

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 2015 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 2015 Chevrolet Silverado - Engine Control Module Power Relay Control Circuit Low - AutoCodes.com — P0686 2015 Chevrolet Silverado Code - Engine Control Module Power Relay Control Circuit Low

What does this mean?

What are the Possible Causes of the DTC P0686 2015 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 2015 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 2015 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 2015 Chevrolet Silverado code?

Need more information on how to fix the P0686 2015 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 2015 Chevrolet Silverado Code

1. What does the OBDII code P0686 mean on a 2015 Chevrolet Silverado?

P0686 indicates a problem with the Engine Control Module (ECM) Power Relay Control Circuit, specifically that the voltage is lower than expected.

2. What are the common symptoms of a P0686 code?

Symptoms may include difficulty starting the engine, engine stalling, reduced power, or a no-start condition.

3. What causes the P0686 code to appear?

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

4. Can a bad battery cause a P0686 code?

Yes, a weak or failing battery can result in low voltage to the ECM power relay, triggering the P0686 code.

5. How is the P0686 code diagnosed?

A mechanic will typically check the ECM relay, inspect wiring and connectors for damage or corrosion, test voltage levels, and use a scan tool to monitor the ECM power relay circuit.

6. What are some common fixes for the P0686 code?

Repairs may include replacing the ECM power relay, repairing or replacing damaged wiring, cleaning corroded connectors, or, in rare cases, replacing the ECM.

7. Can I drive my 2015 Chevrolet Silverado with a P0686 code?

It is not recommended to drive with this code, as it can lead to engine stalling or a no-start condition, potentially leaving you stranded.

8. How much does it cost to fix a P0686 code?

The cost depends on the root cause. Replacing an ECM relay can cost $20-$50 for the part, while wiring repairs or ECM replacement can be significantly higher, ranging from $100 to $1,000 or more.

9. Does clearing the P0686 code fix the problem?

Clearing the code will turn off the check engine light temporarily, but the underlying issue must be resolved to prevent the code from returning.

10. Can a P0686 code damage the engine?

While the code itself may not directly damage the engine, it can lead to stalling or no-start conditions, which can be dangerous in certain driving situations.