AutoCodes – Buick – P0689 Buick

P0689 Buick 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 Buick 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 3,965

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 P0689 Buick 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 Buick - Electronic Control Module Power Relay Sense Circuit Low - AutoCodes.com — P0689 Buick Code - Electronic Control Module Power Relay Sense Circuit Low

What does this mean?

What are the Possible Causes of the DTC P0689 Buick?

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 Buick?

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 Buick 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 Buick code?

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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 P0689 Buick Code

1. What are the common symptoms of OBDII code P0689 in a Buick?

- Common symptoms include engine stalling, difficulty starting the vehicle, and illuminated check engine light.

2. What does the OBDII code P0689 for a Buick mean?

- The code indicates a fault in the Electronic Control Module Power Relay Sense Circuit, specifically a low voltage condition.

3. What are the possible causes of OBDII code P0689 in a Buick?

- Possible causes include a faulty power relay, damaged wiring or connectors, a defective Electronic Control Module (ECM), or a weak battery.

4. How can I diagnose the cause of OBDII code P0689 in my Buick?

- Diagnose the issue by checking the power relay and associated wiring, testing the ECM, and ensuring the battery is in good condition.

5. Can I still drive my Buick with OBDII code P0689 present?

- It is not recommended to drive the vehicle with code P0689 as it can lead to engine performance issues and potential stalling.

6. How can I repair OBDII code P0689 in my Buick?

- Repair options include replacing the faulty power relay, repairing damaged wiring, replacing the ECM if necessary, and ensuring a strong battery connection.

7. Will resetting the OBDII code P0689 in my Buick solve the issue?

- Resetting the code may temporarily clear the check engine light, but it will not fix the underlying problem causing code P0689.

8. Can a DIY enthusiast fix OBDII code P0689 in a Buick?

- Depending on the skill level, a DIY enthusiast may be able to diagnose and repair code P0689 by following repair guides and using appropriate tools.

9. How much does it cost to repair OBDII code P0689 in a Buick at a professional mechanic?

- Repair costs can vary, but expect to pay for diagnostic time, parts such as a relay or ECM, and labor, which can range from a couple hundred to over a thousand dollars.

10. Is OBDII code P0689 a common issue in Buick vehicles?

- While not extremely common, code P0689 can occur in Buick vehicles due to various electrical system issues, so it's important to address the problem promptly.