AutoCodes – GMC – P0689 2018 GMC Sierra

P0689 2018 GMC Sierra Code - Electronic Control Module Power Relay Sense 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: P0689 2018 GMC Sierra indicates Electronic Control Module Power Relay Sense 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 207

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 P0689 2018 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 P0689 2018 GMC Sierra - Electronic Control Module Power Relay Sense Circuit Low - AutoCodes.com — P0689 2018 GMC Sierra Code - Electronic Control Module Power Relay Sense Circuit Low

What does this mean?

What are the Possible Causes of the DTC P0689 2018 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 P0689 2018 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 P0689 2018 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 P0689 2018 GMC Sierra code?

Need more information on how to fix the P0689 2018 GMC Sierra code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the P0689 2018 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 P0689 2018 GMC Sierra Code

1. What are common symptoms of OBDII code P0689 in a 2018 GMC Sierra?

Symptoms may include difficulty starting the engine, engine stalling, poor vehicle performance, and the illumination of the check engine light.

2. What does the OBDII code P0689 for a 2018 GMC Sierra indicate?

The code signifies a problem with the Electronic Control Module (ECM) Power Relay Sense Circuit being too low, affecting the ECM's ability to function properly.

3. What are possible causes of the Electronic Control Module Power Relay Sense Circuit Low code in a 2018 GMC Sierra?

Causes may include a faulty ECM power relay, damaged wiring or connections in the circuit, a malfunctioning ECM, or issues with the power supply to the ECM.

4. How can I diagnose the cause of the P0689 code in my 2018 GMC Sierra?

Diagnosis typically involves checking the ECM power relay, inspecting the wiring and connections for damage, testing the ECM for proper function, and ensuring the power supply to the ECM is stable.

5. What are the repair options for fixing the Electronic Control Module Power Relay Sense Circuit Low issue in a 2018 GMC Sierra?

Repair options may include replacing the ECM power relay, repairing or replacing damaged wiring or connections, testing and potentially replacing the ECM, and ensuring a stable power supply to the ECM.

6. Can I drive my 2018 GMC Sierra with the P0689 code present?

It is not recommended to drive your vehicle with the P0689 code active, as it can lead to engine performance issues and potential stalling, posing a safety risk.

7. How much does it typically cost to repair the ECM Power Relay Sense Circuit Low issue in a 2018 GMC Sierra?

Costs can vary depending on the specific cause of the problem, but repairs for this code may range from $200 to $600, including parts and labor.

8. Is it possible to reset the P0689 code in a 2018 GMC Sierra without fixing the underlying issue?

While you can clear the code with an OBDII scanner, it is crucial to address the root cause of the problem to prevent further issues and ensure proper vehicle operation.

9. How long does it take to repair the Electronic Control Module Power Relay Sense Circuit Low problem in a 2018 GMC Sierra?

The repair time can vary based on the specific repair needed, but it typically takes a few hours to a full day to diagnose and fix the issue properly.

10. Can a DIY enthusiast fix the P0689 code in a 2018 GMC Sierra themselves?

While some may have the skills to address simpler aspects like checking connections or relays, diagnosing and repairing the ECM or wiring issues may require professional expertise and specialized tools.