Airflow Sensor

Airflow sensor is located inside air cleaner assembly. Intake air temperature sensor and barometric pressure sensor are built into airflow sensor. The airflow sensor senses intake air volume and sends a signal to the Electronic Control Unit (ECU). Using airflow sensor and engine RPM signal, ECU makes computations to determine basic fuel injection timing.

Air temperature sensor sends signal to ECU to adjust and correct amount of fuel to be injected. Barometric pressure sensor senses barometric pressure and converts it to electrical voltage signals. Voltage signals are sent to ECU to calculate vehicle altitude, and correct fuel injection quantity and timing for optimum air/fuel ratio. This improves driveability at high altitudes.

Coolant Temperature Sensor (CTS)

The CTS is located on thermostat housing. CTS monitors coolant temperature and sends a voltage signal to ECU. CTS has a built-in thermistor, whose resistance varies according to coolant temperature. The ECU determines engine temperature based on output voltage of CTS to provide optimum mixture enrichment when engine is cold.