AutoCodes – Generic – P0687

P0687 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 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.

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Code Popularity 23,435

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 18, 2022

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code P0687 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 - Engine Control Module Power Relay Control Circuit High - AutoCodes.com — P0687 Code - Engine Control Module Power Relay Control Circuit High

What does this mean?

What are the Possible Causes of the DTC P0687?

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?

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 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 code?

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

Need Help with the Code?

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

Information for Specific Makes

P0687 Audi — Engine Control Module Power Relay Control Circuit High
P0687 BMW — Engine Control Module Power Relay Control Circuit High
P0687 Buick — Engine Control Module Power Relay Control Circuit High
P0687 Cadillac — Engine Control Module Power Relay Control Circuit High
P0687 Chevrolet — Engine Control Module Power Relay Control Circuit High
P0687 Chrysler — Engine Control Module Power Relay Control Circuit High
P0687 Dodge — Engine Control Module Power Relay Control Circuit High
P0687 Ford — Engine Control Module Power Relay Control Circuit High
P0687 GMC — Engine Control Module Power Relay Control Circuit High
P0687 Isuzu — Engine Control Module Power Relay Control Circuit High
P0687 Jeep — Engine Control Module Power Relay Control Circuit High
P0687 Lincoln — Engine Control Module Power Relay Control Circuit High
P0687 Mercury — Engine Control Module Power Relay Control Circuit High
P0687 MINI — Engine Control Module Power Relay Control Circuit High
P0687 Pontiac — Engine Control Module Power Relay Control Circuit High
P0687 Saturn — Engine Control Module Power Relay Control Circuit High
P0687 Suzuki — Engine Control Module Power Relay Control Circuit High
P0687 Volkswagen — Engine Control Module Power Relay Control Circuit High

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 Code

1. What are the common symptoms of OBDII code P0687?

- Common symptoms of P0687 include rough idling, engine stalling, difficulty starting the vehicle, and illuminated Check Engine light.

2. What causes the OBDII code P0687 to be triggered?

- The code P0687 is triggered when the Engine Control Module (ECM) detects a high voltage condition in the power relay control circuit.

3. How can I diagnose the cause of OBDII code P0687?

- To diagnose P0687, you can start by checking the power relay, wiring connections, and the ECM for any faults or damages.

4. Can a faulty battery cause OBDII code P0687 to appear?

- Yes, a weak or faulty battery can sometimes trigger code P0687 due to insufficient power supply to the ECM.

5. Is it safe to continue driving with OBDII code P0687 present?

- It is not recommended to continue driving with code P0687 present, as it can lead to further issues and potential damage to the engine control system.

6. How can I repair OBDII code P0687?

- Repairing code P0687 typically involves replacing the faulty power relay, repairing any damaged wiring, or addressing any issues with the ECM.

7. Are there any DIY tips for fixing OBDII code P0687?

- DIY tips for fixing P0687 include checking and cleaning the power relay contacts, ensuring proper wiring connections, and testing the battery voltage.

8. Can a mechanic reset the OBDII code P0687 after repairs are made?

- Yes, a mechanic can reset the code P0687 using a diagnostic scanner after repairing the underlying issue to clear the Check Engine light.

9. What are the potential risks of ignoring OBDII code P0687?

- Ignoring code P0687 can lead to poor engine performance, reduced fuel efficiency, and potential damage to other engine components over time.

10. Is it necessary to visit a mechanic for OBDII code P0687 diagnosis and repair?

- While some DIY troubleshooting is possible, it is recommended to visit a mechanic for a proper diagnosis and repair of code P0687 to ensure the issue is resolved correctly.