Engine-Codes.com
Engine-Codes – Generic – P120A

P120A Code - Secondary Fuel Injector Bank 1 Insufficient Flow

Quick Answer

The P120A diagnostic trouble code (DTC) indicates that there is insufficient flow detected in the secondary fuel injector of bank 1. Common causes include Clogged or dirty secondary fuel injector, Malfunctioning fuel injector driver in the ECM, Wiring fault in the injector circuit. 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
P120A indicates Secondary Fuel Injector Bank 1 Insufficient Flow .
Common causes
Common causes include Clogged or dirty secondary fuel injector, Malfunctioning fuel injector driver in the ECM, Wiring fault in the injector circuit.
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.
What is this?
Table of contents Created and updated by William Orellana on Sep 09, 2024
💬 Need more help? Ask Auto Expert for instant answers — it's free!
AutoCodes App

Fix Your Car Smarter

Try the New AutoCodes App!

Get complete OBDII diagnostics, repair solutions, and cost estimates, plus AI chat support on demand.

AutoCodes App on Google Play

Code P120A Description

The P120A diagnostic trouble code (DTC) indicates that there is insufficient flow detected in the secondary fuel injector of bank 1. In a multi-cylinder engine, the fuel injectors are responsible for delivering the precise amount of fuel into the combustion chamber for ignition. When the secondary fuel injector in bank 1 fails to provide enough fuel, it can lead to a lean air-fuel mixture, which may result in poor engine performance, reduced fuel efficiency, and potential damage to the engine components over time.

OBDII Code P120A - Secondary Fuel Injector Bank 1 Insufficient Flow
P120A Code - Secondary Fuel Injector Bank 1 Insufficient Flow

Common Causes of P120A

  1. Clogged or dirty secondary fuel injector
  2. Malfunctioning fuel injector driver in the ECM
  3. Wiring fault in the injector circuit
  4. Fuel delivery system issue
  5. Low fuel pressure

Symptoms of P120A

  1. Engine misfires
  2. Rough idling
  3. Hesitation during acceleration
  4. Reduced power output
  5. Stalling

How to Fix P120A

  1. Diagnose the issue by using a scan tool to check for the specific cylinder with the insufficient fuel flow.
  2. Inspect the secondary fuel injector for clogs or dirt, and clean or replace it as necessary.
  3. Check the fuel injector driver in the ECM for any faults and repair or replace it if needed.
  4. Inspect the wiring in the injector circuit for any damage or loose connections, and repair as required.
  5. Test the fuel pressure in the system to ensure it meets the manufacturer's specifications and address any issues found.

Cost to Fix P120A

The typical repair costs for addressing a P120A code can vary depending on the specific cause of the issue and the labor rates at auto repair shops. On average, the repair costs for this type of fuel injector problem can range from $200 to $500, including parts and labor. However, it's important to note that the total cost can increase if additional components need to be replaced or if there are underlying issues in the fuel delivery system. It is advisable to consult with a qualified mechanic or service center to obtain a more accurate estimate based on your vehicle's make and model, as well as the severity of the problem.

Need more information about the P120A code?

Need more information on how to fix the P120A code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the P120A code diagnosed by a professional: Find a repair shop in your area

Code P120A Information for Specific Makes

  • P120A Ford — Secondary Fuel Injector Bank 1 Insufficient Flow
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 P120A Code

1. What are the common symptoms of OBDII code P120A (Secondary Fuel Injector Bank 1 Insufficient Flow)?

- Common symptoms include rough idling, reduced engine performance, misfires, and potentially an illuminated check engine light.

2. What are the typical causes of code P120A (Secondary Fuel Injector Bank 1 Insufficient Flow)?

- Causes may include a clogged fuel injector, faulty fuel injector wiring, low fuel pressure, or a problem with the fuel injector control module.

3. How can I diagnose the issue related to OBDII code P120A?

- Diagnosing the issue may involve inspecting the fuel injector, checking the wiring harness for any damage, testing fuel pressure, and scanning the vehicle for other related trouble codes.

4. Can a dirty fuel system contribute to code P120A?

- Yes, a dirty fuel system can restrict fuel flow and potentially lead to insufficient flow in the secondary fuel injector of Bank 1, triggering code P120A.

5. What are some recommended repair tips for addressing code P120A?

- Repair tips may include cleaning or replacing the fuel injector, repairing any damaged wiring, ensuring proper fuel pressure, and clearing the trouble code from the vehicle's computer.

6. Is it safe to continue driving with OBDII code P120A present?

- It is not recommended to continue driving with code P120A as it can lead to further engine damage and decreased performance. It's best to address the underlying issue promptly.

7. Can a DIY enthusiast fix OBDII code P120A at home?

- Depending on the root cause, some DIY enthusiasts may be able to address code P120A at home by following repair guides and having the necessary tools and knowledge.

8. How serious is OBDII code P120A?

- Code P120A should be addressed promptly as it can impact the engine's performance and fuel efficiency. Ignoring the issue may lead to more severe problems over time.

9. Will resetting the trouble code fix OBDII code P120A permanently?

- Simply resetting the code may temporarily turn off the check engine light, but it will not fix the underlying issue causing code P120A. It's essential to diagnose and address the root problem.

10. Can a malfunctioning oxygen sensor trigger OBDII code P120A?

- While a malfunctioning oxygen sensor can impact fuel delivery, it is less likely to directly trigger code P120A. The issue is more commonly related to fuel injector problems or fuel system issues.

Discuss the causes and fixes for P120A OBDII Code

Submit a New Comment

Code P120A comments

No comments found for this page.