AutoCodes – Scion – P0102 Scion

P0102 Scion Code - Mass or Volume Air Flow Circuit Low Input

Quick Answer

The Mass Air Flow (MAF) meter sub-assembly is a sensor that measures the amount of air flowing through the throttle valve. 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: P0102 Scion indicates Mass or Volume Air Flow Circuit Low 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 17,978

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 Aug 22, 2022

Description
Step-by-Step Diagnostic Guide
Possible Causes
How To Fix
Tech Notes
Cost to Diagnose
Comments
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Code P0102 Scion Description

The Mass Air Flow (MAF) meter sub-assembly is a sensor that measures the amount of air flowing through the throttle valve. The Engine Control Module (ECM) uses this information to determine fuel injection duration and to provide an appropriate air-fuel ratio.
Inside the mass air flow meter sub-assembly, there is a heated platinum wire which is exposed to the flow of intake air. By applying a specific electrical current to the wire, the ECM heats it to a specific temperature. The flow of incoming air cools both the wire and an internal thermistor, affecting their resistance. To maintain a constant current value, the ECM varies the voltage applied to the wire and internal thermistor. The voltage level is proportional to the airflow through the sensor, and the ECM uses it to calculate the intake air volume.
The circuit is constructed so that the platinum hot wire and the temperature sensor create a bridge circuit, and the power transistor is controlled so that the potentials of A and B remain equal to maintain the predetermined temperature.
If there is a defect or an open or short circuit in the mass air flow meter sub-assembly, the voltage level deviates from the normal operating range. The ECM interprets this deviation as a malfunction in the mass air flow meter sub-assembly circuit and stores a Diagnostic Trouble Code (DTC).

OBDII Code P0102 Scion - Mass or Volume Air Flow Circuit Low Input - AutoCodes.com — P0102 Scion Code - Mass or Volume Air Flow Circuit Low Input

What does this mean?

What are the Possible Causes of the DTC P0102 Scion?

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 P0102 Scion?

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 P0102 Scion 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 P0102 Scion code?

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Information for Specific Scion Models

P0102 2005 Scion xB — Mass or Volume Air Flow Circuit Low Input
P0102 2006 Scion xB — Mass or Volume Air Flow Circuit Low Input
P0102 2007 Scion xB — Mass or Volume Air Flow Circuit Low Input

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.