Toyota Corolla E120 Mass Air Flow Meter (M1)

Toyota Corolla 9 ^th Generation (E120)

Mass Air Flow Meter Assembly Wiring Guide: DIY Pinout Diagram

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What is:A Mass Air Flow (MAF) Meter is a key component in a vehicle’s engine management system. It measures the amount of air entering the engine intake so the Engine Control Unit (ECU) can calculate the correct amount of fuel to inject for optimal combustion.

1. Introduction

      The Toyota Corolla E120 Toyota Corolla E120 Mass Air Flow (MAF) Meter measures the amount of air entering the engine to ensure the correct air-fuel mixture for efficient combustion. It uses a hot wire sensing system to detect airflow changes and sends signals to the Engine Control Module (ECM) for fuel adjustment. Located between the air filter box and throttle body, the MAF meter helps optimize engine performance, fuel economy, and emission control in the Corolla E120.

Mass Air Flow Meter Assembly – Most Common in Toyota Corolla (E120)

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1. Component
   • MAF sensor itself (OEM / aftermarket) – The main unit measuring intake air flow.
   • Gasket / O-ring / seal – Ensures airtight sealing between the MAF housing and intake duct.
   • Intake air filter / air filter element– Dirty filters can contaminate the MAF sensor, so filter replacement is related.
   • Air intake duct / hose / piping – The ducting that directs air through the MAF to the throttle body.
   • ECU / engine control module –Uses the MAF signal; in some diagnostic or replacement scenarios the ECU may need re-programming.
   • Wiring harness / connector / pigtails – Ensures proper signal, power, and ground connections to the sensor.
   • Intake manifold / throttle body – Downstream parts that work in tandem with airflow measurement for fuel computation.
   • Vacuum hoses / PCV hoses – Leaks here can affect airflow readings and sensor behavior.
   • Sensor mounting screws / clips – Hardware used to mount/secure the MAF sensor in the intake tract.

2. Mass Air Flow Meter Assembly Wiring Diagram & Pinout

A. Connector Location

• Mass Air Flow Meter Assembly Position: Between the air filter box and the throttle body.
• Connector Type:
  • M1 (5 pin) Black housing

B. Wiring Table

Mass Air Flow Meter (M1)

M1 TERMINALS OF Mass Air Flow Meter CONECTOR

Terminal No	Symbol (Pin Definition)	Wiring (Color Code) & Color	Electrical Paths
1	+B	(B) Black	➔ ✠ I10 ➔ EA1 9 ➳ 1 3 ➤ [EFI Relay]
2	E2G	(L-W) Blue/White	➔ E4 32 (EVG) [Engine Control Module]
3	VG	(G) Green	➔ E4 24 (VG) [Engine Control Module]
4	THA	(Y-B) Yellow/Black	➔ E3 20 (THA) [Engine Control Module]
5	E2	(BR) Brown	➔ J2 H ⬌ J3 F ➔ E3 28 (E2) [Engine Control Module]