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P0686 2017 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 2017 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 289

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 2017 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 2017 Chevrolet Silverado - Engine Control Module Power Relay Control Circuit Low - AutoCodes.com — P0686 2017 Chevrolet Silverado Code - Engine Control Module Power Relay Control Circuit Low

What does this mean?

What are the Possible Causes of the DTC P0686 2017 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 2017 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 2017 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 2017 Chevrolet Silverado code?

Need more information on how to fix the P0686 2017 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 2017 Chevrolet Silverado Code

1. What does the OBDII code P0686 mean for a 2017 Chevrolet Silverado?

P0686 indicates a problem with the Engine Control Module (ECM) Power Relay Control Circuit, specifically that the circuit voltage is too low.

2. What are the common symptoms of code P0686 in a 2017 Chevrolet Silverado?

Typical symptoms include difficulty starting the engine, engine stalling, reduced performance, or a no-start condition.

3. What causes the P0686 code to appear in a 2017 Chevrolet Silverado?

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

4. Can a weak battery trigger the P0686 code in my Silverado?

Yes, a weak or failing battery can cause insufficient voltage to the ECM power relay, potentially triggering the P0686 code.

5. Is it safe to drive my 2017 Silverado with the P0686 code active?

It is not recommended to drive with this code active, as it may lead to stalling or difficulty restarting, which can create unsafe driving conditions.

6. How do I diagnose the P0686 code on my Silverado?

Begin by checking the ECM power relay for proper operation, inspecting related wiring and connectors for damage, and testing the battery voltage to ensure itâ€™s within a normal range.

7. How can I fix the P0686 code on a 2017 Chevrolet Silverado?

Repairs may involve replacing a faulty ECM power relay, repairing or replacing damaged wires or connectors, and in some cases, replacing the ECM itself.

8. Can a blown fuse cause the P0686 code in my Silverado?

Yes, a blown fuse in the ECM power circuit can interrupt the power supply and trigger the P0686 code.

9. What tools do I need to troubleshoot the P0686 code?

Youâ€™ll need an OBDII scanner, a multimeter for testing voltage and continuity, and possibly wiring diagrams for the ECM power circuit.

10. How much does it typically cost to fix the P0686 code on a 2017 Silverado?

Repair costs can vary, but replacing a faulty ECM power relay typically costs $50â€“$150, while more extensive wiring repairs or ECM replacement can exceed $500.