Thread: A list of sensors and how they work?

Originally Posted by CT Tech

Remove the Mass airflow sensor and GENTLY clean the heated wires with a can of carb, brake or MAF cleaner. I have seen a lot of dirty MAF's make a car run really funny. You will need a tamper proof torx to remove the sensor.

I would think that brake and carb cleaner will damage the MAF. Best to use plastic-safe throttle body cleaner, or electronics cleaner with NO lanolin.

MAF: Works by a pair of thermistors. One is heated, one is not. The MAF calculates air flow by how the heated element is cooled to ambient by air flow, and then does the math.

TPS: Analog 5v potentiometer.

MAP: Analog 5v pressure sensing, most likely by a strain gauge.

ABS: Also Hall-effect or FET devices that pulse a signal to the EBTCM as the magnetic reluctor wheel in the hub rotates.

IAT: Not a sensor, but is a motor-driven valve that regulates idle air. When cleaning, be sure NOT to move the pintle, or damage can result. I clean mine with TB cleaner and a LOT of Q-tips to clean the valve seat.

Most engine pressure and temp sensors are analog thermistors referenced to ground. The coolant temp sender is actually 2 thermistors in one package. One sends to the PCM, the other to the instrument cluster.

I think the low coolant and low oil senders are either resistance to ground through the fluid, or proximity sensors.