Understanding the wiring diagram for your Toyota’s 5-pin mass air flow (MAF) sensor is crucial for proper engine performance and diagnostics. This article provides a comprehensive guide to the two common wiring configurations found in Toyota vehicles, along with explanations of each pin’s function.
The MAF sensor measures the amount of air entering the engine, allowing the Engine Control Unit (ECU) to calculate the correct fuel injection. A faulty MAF sensor can lead to poor fuel economy, rough idling, and even engine stalling. Knowing how to identify the correct wiring configuration for your specific Toyota model is the first step in troubleshooting and ensuring accurate readings.
Typical 5-Wire Toyota MAF Sensor
Identifying Your Toyota MAF Sensor Wiring Configuration
Toyota utilizes two distinct wiring configurations for their 5-pin MAF sensors. Before consulting the diagrams below, it’s essential to determine which configuration applies to your vehicle. The easiest method is to use an ohmmeter to measure the resistance between specific pins on the sensor connector.
Early Configuration: Measure the resistance between pins 1 and 2. A reading of approximately 2.21kΩ to 2.69kΩ at 20°C (68°F) indicates the early configuration.
Later Configuration: Measure the resistance between pins 4 and 5. A reading of approximately 2.21kΩ to 2.69kΩ at 20°C (68°F) indicates the later configuration.
Toyota 5-Pin MAF Sensor Wiring Diagrams
Early Configuration (JZS161 2JZGE before 07/2000, JZS161 2JZGTE, JZA80 2JZGTE VVTi)
| Pin | Symbol | Definition | Input/Output | Description |
|---|---|---|---|---|
| 1 | THA | Air Temperature Sensor | Output | Sends air temperature data to the ECU. |
| 2 | E2 | Sensor Ground (Air Temperature Sensor) | Input | Ground for the air temperature sensor circuit. |
| 3 | EVG | Mass Airflow Sensor Ground | Input | Ground for the MAF sensor circuit. |
| 4 | +B | EFI Main Relay Switched Power | Input | Provides power to the MAF sensor. |
| 5 | VG | Engine Airflow | Output | Sends airflow data to the ECU. |
THA Resistance Curve for Toyota MAF Sensor
Later Configuration (JZS161 2JZGE after 07/2000, JZS171 1JZGTE)
| Pin | Symbol | Definition | Input/Output | Description |
|---|---|---|---|---|
| 1 | +B | EFI Main Relay Switched Power | Input | Provides power to the MAF sensor. |
| 2 | EVG (or E2G) | Mass Airflow Sensor Ground | Input | Ground for the MAF sensor circuit. |
| 3 | VG | Engine Airflow | Output | Sends airflow data to the ECU. |
| 4 | THA | Air Temperature Sensor | Output | Sends air temperature data to the ECU. |
| 5 | E2 | Sensor Ground (Air Temperature Sensor) | Input | Ground for the air temperature sensor circuit. |
Another Example of a Toyota 5-Wire MAF Sensor
Conclusion
This guide provides the essential information for understanding the wiring of your Toyota’s 5-pin MAF sensor. Remember to always verify the correct wiring configuration for your specific vehicle model and year before performing any diagnostic or repair work. Using this information, you can effectively troubleshoot MAF sensor issues and ensure optimal engine performance.
