AutoCodes – Mercury – P0279 Mercury

P0279 Mercury Code - Cylinder 7 Injector Circuit Low

Quick Answer

The Engine Control Module (ECM) supplies voltage to each Fuel Injector on the high control circuits. Common causes include Dirty Fuel Injector 7, Faulty Fuel Injector 7, Plugged Fuel Injector 7. 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: P0279 Mercury indicates Cylinder 7 Injector Circuit Low.
Common causes: Common causes include Dirty Fuel Injector 7, Faulty Fuel Injector 7, Plugged Fuel Injector 7.
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.

Save to My Repairs My Repairs

AI answers can be wrong. Verify repairs with testing. Open full chat

Code Popularity 284

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 Jun 02, 2022

Description
Possible Causes
How To Fix
Tech Notes
Cost to Diagnose
FAQs
Comments
Add Comment

💬 Need more help? Ask Coddy for instant answers — it's free!

Code P0279 Mercury Description

The Engine Control Module (ECM) supplies voltage to each Fuel Injector on the high control circuits. The ECM energizes each fuel injector by grounding the low control circuit of the fuel injector. The ECM monitors the status of the fuel injector circuits. When a fuel injector circuit condition is detected by the ECM, the affected fuel injector(s) is disabled. The Diagnostic Trouble Code (DTC) will be set when the ECM detects the fuel injector control circuit is shorted to ground for greater than 2 s.

OBDII Code P0279 Mercury - Cylinder 7 Injector Circuit Low - AutoCodes.com — P0279 Mercury Code - Cylinder 7 Injector Circuit Low

What does this mean?

What are the Possible Causes of the DTC P0279 Mercury?

Dirty Fuel Injector 7
Faulty Fuel Injector 7
Plugged Fuel Injector 7
Fuel injector 7 harness is open or shorted
Fuel injector 7 circuit poor electrical connection

How to Fix the DTC P0279 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 does this mean?

Code Tech Notes

A clogged or partially clogged fuel injector can cause this code. Start by performing an injector flush before replacing the injector.

What is the Cost to Diagnose the Code?

Labor: 1.0

To diagnose the P0279 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 P0279 Mercury code?

Need more information on how to fix the P0279 Mercury code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the P0279 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 P0279 Mercury Code

1. What are the common symptoms of OBDII code P0279 on a Mercury related to the Cylinder 7 Injector Circuit Low?

- Common symptoms include rough idling, poor engine performance, decreased fuel efficiency, and possible misfires.

2. What are the possible causes of the P0279 OBDII code in a Mercury indicating a Cylinder 7 Injector Circuit Low?

- The code can be triggered by issues such as a faulty fuel injector in cylinder 7, wiring or connector problems, or a problem with the Engine Control Module (ECM).

3. How can I diagnose the cause of the P0279 code on my Mercury?

- Diagnostic steps may include checking the injector in cylinder 7 for proper operation, inspecting the wiring and connectors for damage, and using a scan tool to monitor injector performance.

4. Can a dirty fuel injector cause the P0279 code on a Mercury?

- Yes, a dirty or clogged fuel injector in cylinder 7 can potentially cause a low circuit condition and trigger the P0279 code.

5. Is it safe to drive my Mercury with the P0279 code present?

- It is not recommended to drive the vehicle with the P0279 code as it can lead to further engine damage and decreased performance. It's best to address the issue promptly.

6. How can I repair the Cylinder 7 Injector Circuit Low issue on my Mercury?

- Repair options may include cleaning or replacing the fuel injector, repairing any damaged wiring or connectors, or replacing the ECM if necessary.

7. Can I reset the P0279 code on my Mercury without fixing the underlying issue?

- While you can clear the code temporarily, it will likely reappear if the root cause is not addressed. It's essential to fix the problem causing the code to prevent further issues.

8. Will a P0279 code on my Mercury cause it to fail an emissions test?

- Yes, the P0279 code indicating a Cylinder 7 Injector Circuit Low can cause your Mercury to fail an emissions test due to its impact on engine performance and fuel efficiency.

9. How much does it typically cost to repair a P0279 OBDII code on a Mercury?

- The cost of repair can vary depending on the specific cause of the code, but it may range from a few hundred to over a thousand dollars, including parts and labor.

10. Can a DIY enthusiast fix the P0279 code issue on a Mercury, or is it best left to professionals?

- While some DIYers with automotive repair experience may be able to address the issue, dealing with fuel injectors and ECM problems can be complex. It's often best to consult a professional mechanic for proper diagnosis and repair.