AutoCodes – Generic – P1240

P1240 Code - Injector Circuit Open Cylinder 4

Quick Answer

P1240 indicates Injector Circuit Open Cylinder 4. Common causes include Faulty Fuel Injector 4, Fuel Injector 4 harness is open or shorted, Fuel Injector 4 circuit poor electrical connection. 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: P1240 indicates Injector Circuit Open Cylinder 4.
Common causes: Common causes include Faulty Fuel Injector 4, Fuel Injector 4 harness is open or shorted, Fuel Injector 4 circuit poor electrical connection.
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 28,762

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 20, 2019

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code P1240 Description

OBDII Code P1240 - Injector Circuit Open Cylinder 4 - AutoCodes.com — P1240 Code - Injector Circuit Open Cylinder 4

What does this mean?

What are the Possible Causes of the DTC P1240?

Faulty Fuel Injector 4
Fuel Injector 4 harness is open or shorted
Fuel Injector 4 circuit poor electrical connection

How to Fix the DTC P1240?

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 P1240 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 P1240 code?

Need more information on how to fix the P1240 code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the P1240 code diagnosed by a professional: Find a repair shop in your area

Information for Specific Makes

P1240 Audi — Injector Circuit Open Cylinder 4
P1240 Buick — Injector Circuit Cylinder 7 Intermittent
P1240 Cadillac — Injector Circuit Cylinder 7 Intermittent
P1240 Chevrolet — Injector Circuit Cylinder 7 Intermittent
P1240 GMC — Injector Circuit Cylinder 7 Intermittent
P1240 Isuzu — High Fuel Pressure Regulator Circuit Open
P1240 Jaguar — Sensor Power Supply Malfunction
P1240 Mitsubishi — Ignition Angle
P1240 Saab — Throttle Position Motor Short Circuit
P1240 Volkswagen — Injector Circuit Open Cylinder 4

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 P1240 Code

1. What are the common symptoms of OBDII code P1240 (Injector Circuit Open Cylinder 4)?

- The common symptoms include rough idling, engine misfires, decreased fuel efficiency, and potential stalling of the vehicle.

2. What are the possible causes of OBDII code P1240?

- The code P1240 can be caused by a faulty fuel injector in cylinder 4, damaged wiring or connectors in the injector circuit, or a problem with the Engine Control Module (ECM).

3. How can I diagnose the issue related to OBDII code P1240?

- Diagnosing the issue involves using a scan tool to check for the specific code, inspecting the cylinder 4 fuel injector and its connections, and testing the wiring for any breaks or shorts.

4. Can a DIY enthusiast repair OBDII code P1240 at home?

- While it is possible to repair the code P1240 at home, it is recommended to have some level of experience with automotive diagnostics and repair due to the complexity of the fuel injection system.

5. What are some repair tips for fixing OBDII code P1240?

- Repair tips include checking the injector wiring for damage, ensuring proper connections, testing the injector for functionality, and replacing the injector if necessary.

6. Is it safe to continue driving with OBDII code P1240 present?

- It is not recommended to continue driving with the code P1240 as it can lead to further damage to the engine and negatively impact the vehicle's performance.

7. How much does it typically cost to repair OBDII code P1240?

- The cost of repairing OBDII code P1240 can vary depending on the root cause of the issue, but it may range from $150 to $500 for parts and labor.

8. Can a bad fuel injector cause OBDII code P1240?

- Yes, a faulty fuel injector in cylinder 4 can trigger code P1240 due to the injector circuit being open or not functioning properly.

9. How long does it take to repair OBDII code P1240?

- The repair time for OBDII code P1240 can vary based on the extent of the issue, but it typically takes a few hours to diagnose and fix the problem.

10. Are there any preventative measures to avoid OBDII code P1240 in the future?

- Regular maintenance, such as cleaning the fuel injectors and ensuring proper wiring connections, can help prevent OBDII code P1240 from occurring in the future.