AutoCodes – Mercury – P0689 Mercury

P0689 Mercury Code - Electronic Control Module Power Relay Sense Circuit Low

Quick Answer

The Powertrain Control Module (PCM) monitors the voltage on the Ignition Switch Position Run (ISP-R) and the Fuel Injector Power Monitor (INJPWRM) circuits. Common causes include Weak battery, Low voltage while cranking, Faulty Powertrain Control Module (PCM) 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 Mercury indicates Electronic Control Module Power Relay Sense Circuit Low.
Common causes: Common causes include Weak battery, Low voltage while cranking, Faulty Powertrain Control Module (PCM) 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 1,342

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 May 05, 2019

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code P0689 Mercury Description

The Powertrain Control Module (PCM) monitors the voltage on the Ignition Switch Position Run (ISP-R) and the Fuel Injector Power Monitor (INJPWRM) circuits. This DTC sets when the voltage on the ISP-R and the INJPWRM circuit voltages do not correspond for a calibrated period of time.

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

What does this mean?

What are the Possible Causes of the DTC P0689 Mercury?

Weak battery
Low voltage while cranking
Faulty Powertrain Control Module (PCM) relay
Blown PCM fuse
Faulty PCM
PCM harness is open or shorted
PCM circuit poor electrical connection

How to Fix the DTC P0689 Mercury?

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 Mercury 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 Mercury code?

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

Need Help with the Code?

Get the P0689 Mercury 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 Mercury Code

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

The common symptoms of code P0689 include difficulty starting the engine, rough idling, stalling, and possible illumination of the Check Engine Light.

2. What causes the OBDII code P0689 in a Mercury car?

Code P0689 in a Mercury is usually caused by a malfunction in the electronic control module power relay sense circuit, leading to low voltage readings.

3. How can I diagnose the OBDII code P0689 in my Mercury?

To diagnose code P0689, you will need a diagnostic scanner to read the fault code, check the power relay connections and wiring, and test the electronic control module power relay for proper function.

4. Can a faulty battery cause OBDII code P0689 to appear in a Mercury vehicle?

Yes, a faulty battery or poor battery connection can sometimes trigger code P0689 due to insufficient power supply to the electronic control module.

5. What are some repair tips for fixing OBDII code P0689 in a Mercury?

Repair tips for resolving P0689 may include checking and repairing any damaged wiring, replacing the electronic control module power relay if necessary, and ensuring a strong connection to the battery.

6. Is it safe to continue driving my Mercury with OBDII code P0689 present?

It is not recommended to drive your Mercury with code P0689 present, as it can lead to potential issues with starting the engine or other electrical malfunctions.

7. Can a DIY enthusiast fix OBDII code P0689 in a Mercury at home?

While some aspects of diagnosing and repairing code P0689 can be done at home by experienced DIY enthusiasts, it is advised to consult a professional mechanic for accurate diagnosis and repair.

8. How much does it cost to repair OBDII code P0689 in a Mercury at a dealership or auto repair shop?

The cost of repairing code P0689 in a Mercury can vary depending on the extent of the issue, but it may range from $100 to $300 at a dealership or auto repair shop.

9. Will resetting the OBDII code P0689 in my Mercury make it disappear permanently?

Resetting the code may temporarily clear it, but if the underlying issue causing code P0689 is not addressed, it is likely to reappear after driving cycles.

10. Can code P0689 in a Mercury be prevented in the future?

Regular maintenance checks, ensuring proper battery connections, and promptly addressing any electrical issues can help prevent code P0689 from occurring in the future in a Mercury vehicle.