AutoCodes – Subaru – P0103 Subaru

P0103 Subaru Code - Mass or Volume Air Flow Circuit High Input

Quick Answer

The Mass Air Flow (MAF) sensor is placed in the stream of the intake air. Common causes include Dirty Air Filter, Dirty Mass Air Flow (MAF) Sensor, Intake air leaks. 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: P0103 Subaru indicates Mass or Volume Air Flow Circuit High Input.
Common causes: Common causes include Dirty Air Filter, Dirty Mass Air Flow (MAF) Sensor, Intake air leaks.
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 30,133

How popular is this code, among other codes? Low

Repair Importance Level

Urgent (Diagnose now) (3 / 3)

Repair Difficulty Level

Intermediate (2 / 3)

What is this?

Table of contents Created and updated by William Orellana on May 19, 2022

Description
Step-by-Step Diagnostic Guide
Possible Causes
How To Fix
Tech Notes
Cost to Diagnose
FAQs
Comments
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Code P0103 Subaru Description

The Mass Air Flow (MAF) sensor is placed in the stream of the intake air. It measures the intake flow rate by measuring a part of the entire intake flow. It consists of a hot film that is supplied with electric current from the Engine Control Module (ECM). The ECM controls the temperature of the hot film by a certain amount. The heat generated by the hot film is reduced as the intake air flows around it. The more air, the greater the heat loss. Therefore, the ECM must supply more electric current to maintain the temperature of the hot film as air flow increases. The ECM detects the air flow by means of this current change. The Diagnostic Trouble Code (DTC) will be set when the ECM detects that the MAF Sensor Signal is more than the factory specifications.

OBDII Code P0103 Subaru - Mass or Volume Air Flow Circuit High Input - AutoCodes.com — P0103 Subaru Code - Mass or Volume Air Flow Circuit High Input

What does this mean?

What are the Possible Causes of the DTC P0103 Subaru?

Dirty Air Filter
Dirty Mass Air Flow (MAF) Sensor
Intake air leaks
Faulty Mass Air Flow Sensor
Mass Air Flow Sensor harness is open or shorted
Mass Air Flow Sensor circuit poor electrical connection

How to Fix the DTC P0103 Subaru?

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

Before replacing the Mass Air Flow (MAF) Sensor, try replacing the air filter and cleaning the Mass Air Flow Sensor with low compress air or Mass Air Flow Sensor Cleaner. Reset code and drive vehicle. If the code comes back, you must replace the Mass Air Flow Sensor to fix the problem.

What is the Cost to Diagnose the Code?

Labor: 1.0

To diagnose the P0103 Subaru 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.

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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 P0103 Subaru Code

1. What are the common symptoms of OBDII code P0103 in a Subaru related to the Mass or Volume Air Flow Circuit High Input?

The common symptoms include poor fuel economy, rough idling, stalling, lack of power, and the Check Engine Light being illuminated.

2. What are the possible causes of OBDII code P0103 in a Subaru?

Possible causes include a faulty mass air flow sensor, a dirty or contaminated air filter, a vacuum leak, issues with the intake air system, or problems with the wiring or connectors related to the mass air flow sensor.

3. How can I diagnose the OBDII code P0103 in my Subaru?

You can diagnose the code by using an OBDII scanner to retrieve the code and check the live data from the mass air flow sensor. Additionally, inspect the air filter, intake system, vacuum lines, and wiring for any visible issues.

4. Can I still drive my Subaru with OBDII code P0103 present?

It is not recommended to drive your Subaru with this code present, as it can lead to poor engine performance, reduced fuel efficiency, and potential further damage to the engine components.

5. How can I repair OBDII code P0103 in my Subaru?

Repair options include cleaning or replacing the mass air flow sensor, replacing the air filter, fixing any vacuum leaks, checking and repairing wiring or connectors, and ensuring the intake system is free from obstructions.

6. Will resetting the trouble codes make OBDII code P0103 disappear?

Resetting the trouble codes may temporarily clear the Check Engine Light, but if the underlying issue causing code P0103 is not resolved, the code is likely to reappear after driving your Subaru for a certain distance.

7. Is it possible for a Subaru to throw OBDII code P0103 intermittently?

Yes, it is possible for the code to be intermittent, especially if the issue is related to a loose connection, intermittent sensor failure, or sporadic airflow problems within the intake system.

8. How long does it typically take to repair OBDII code P0103 in a Subaru?

The repair time can vary depending on the specific cause of the code. Simple fixes like cleaning the mass air flow sensor or replacing the air filter can be done quickly, while diagnosing and repairing more complex issues may take longer.

9. Are there any preventive measures to avoid OBDII code P0103 in a Subaru?

Regular maintenance, such as changing the air filter according to the manufacturer's recommendations, checking for vacuum leaks, and ensuring the intake system is clean and free from debris, can help prevent code P0103 from occurring.

10. Can a DIY enthusiast fix OBDII code P0103 in a Subaru, or should it be done by a professional mechanic?

Simple tasks like cleaning the mass air flow sensor or replacing the air filter can be done by a DIY enthusiast with some automotive knowledge and the right tools. However, more complex issues may require the expertise of a professional mechanic to diagnose and repair effectively.