AutoCodes – GMC – P0687 2014 GMC Sierra

P0687 2014 GMC Sierra Code - Engine Control Module Power Relay Control Circuit High

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: P0687 2014 GMC Sierra indicates Engine Control Module Power Relay Control Circuit High.
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.

Save to My Repairs My Repairs

AI answers can be wrong. Verify repairs with testing. Open full chat

Code Popularity 220

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
Add Comment

💬 Need more help? Ask Coddy for instant answers — it's free!

Code P0687 2014 GMC Sierra 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 P0687 2014 GMC Sierra - Engine Control Module Power Relay Control Circuit High - AutoCodes.com — P0687 2014 GMC Sierra Code - Engine Control Module Power Relay Control Circuit High

What does this mean?

What are the Possible Causes of the DTC P0687 2014 GMC Sierra?

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 P0687 2014 GMC Sierra?

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 P0687 2014 GMC Sierra 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 P0687 2014 GMC Sierra code?

Need more information on how to fix the P0687 2014 GMC Sierra code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the P0687 2014 GMC Sierra code diagnosed by a professional: Find a repair shop in your area

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 P0687 2014 GMC Sierra Code

1. What are the common symptoms of OBDII code P0687 in a 2014 GMC Sierra?

- Common symptoms include engine stalling, rough idle, difficulty starting the vehicle, and potential loss of power.

2. What does the OBDII code P0687 for a 2014 GMC Sierra indicate?

- The code P0687 indicates a problem with the Engine Control Module (ECM) power relay control circuit being too high.

3. What are the possible causes of OBDII code P0687 in a 2014 GMC Sierra?

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

4. How can I diagnose the OBDII code P0687 in my 2014 GMC Sierra?

- Diagnosing the code involves checking the ECM power relay, inspecting the wiring and connectors for damage, and testing the ECM for proper function.

5. Can I continue driving my 2014 GMC Sierra with OBDII code P0687?

- It is not recommended to continue driving with the code present, as it can lead to further engine performance issues and potential damage if left unresolved.

6. How can I repair OBDII code P0687 in my 2014 GMC Sierra?

- Repairing the code typically involves replacing the faulty ECM power relay, repairing any damaged wiring or connectors, and resetting the code with a diagnostic tool.

7. Is it possible to reset the OBDII code P0687 in a 2014 GMC Sierra without fixing the underlying issue?

- While you can reset the code temporarily, it is important to address the underlying issue to prevent further problems and potential damage to the vehicle.

8. How much does it cost to repair OBDII code P0687 in a 2014 GMC Sierra?

- The cost of repair can vary depending on the extent of the issue, but it typically involves the cost of a new ECM power relay and any labor charges for installation.

9. Can a DIY enthusiast fix OBDII code P0687 in a 2014 GMC Sierra?

- Depending on their skill level and access to tools, a DIY enthusiast may be able to replace the ECM power relay or check for damaged wiring, but more complex issues may require professional assistance.

10. Will OBDII code P0687 cause my 2014 GMC Sierra to fail an emissions test?

- Yes, the presence of code P0687 can cause your vehicle to fail an emissions test due to its impact on engine performance and emissions control systems.