AutoCodes – GMC – P0690 2018 GMC Sierra

P0690 2018 GMC Sierra Code - Electronic Control Module Power Relay Sense 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: P0690 2018 GMC Sierra indicates Electronic Control Module Power Relay Sense 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 205

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 P0690 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 P0690 2018 GMC Sierra - Electronic Control Module Power Relay Sense Circuit High - AutoCodes.com — P0690 2018 GMC Sierra Code - Electronic Control Module Power Relay Sense Circuit High

What does this mean?

What are the Possible Causes of the DTC P0690 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 P0690 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 P0690 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 P0690 2018 GMC Sierra code?

Need more information on how to fix the P0690 2018 GMC Sierra code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the P0690 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 P0690 2018 GMC Sierra Code

1. What does the OBDII code P0690 mean on a 2018 GMC Sierra?

P0690 indicates an issue with the Electronic Control Module (ECM) Power Relay Sense Circuit, specifically a high voltage condition has been detected.

2. What are the common symptoms of a P0690 code?

Symptoms may include the engine not starting, stalling while driving, reduced fuel efficiency, or the Check Engine Light being illuminated.

3. What causes the P0690 code to appear on a GMC Sierra?

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

4. How do I diagnose a P0690 code on my 2018 GMC Sierra?

Diagnosis involves checking the ECM power relay, inspecting the wiring and connectors for damage or corrosion, and testing the circuit voltage with a multimeter.

5. Can I drive my 2018 GMC Sierra with a P0690 code?

Driving with this code is not recommended, as it may lead to engine stalling or failure to restart, potentially leaving you stranded.

6. How do I fix a P0690 code on a GMC Sierra?

Repairs may include replacing the ECM power relay, repairing or replacing damaged wiring, replacing blown fuses, or in rare cases, replacing the ECM.

7. Is the P0690 code related to other issues in the vehicle?

Yes, it can be linked to other electrical issues, such as battery or alternator problems, which may affect the ECM power supply.

8. How much does it cost to repair a P0690 code?

Repair costs vary depending on the issue but typically range from $50 for a relay replacement to $1,000 or more if the ECM needs replacement.

9. Can a weak battery cause the P0690 code to trigger?

Yes, a weak or failing battery can contribute to power supply issues, potentially triggering this code.

10. Do I need to reprogram the ECM after fixing a P0690 code?

Reprogramming the ECM is usually not necessary unless the ECM itself is replaced or updated as part of the repair process.

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