Auto Parts for You: Finding and Buying Sensors

The new sensor/ECU systems in automobiles today are not that easy to understand on the surface, but with a little information they don’t have to drive you crazy. All you have to do is imagine the ECU as a processing unit like your body, and the sensors are like your five senses. They are the system that tells the ECU (engine control unit) and other centers in the car what’s happening with the car on almost all levels.

The Basic Sensors in Your Car

One of the most basic sensors in your car is a temperature sensor. For instance, the coolant temperature sensor will read the temperature of the coolant that goes to your car’s engine, and feeds information to the ECU so it can make adjustments as needed. Without the coolant temperature sensor, your coolant would get too hot—just like the old days when you would remove a radiator cap and have boiling coolant spray five feet in the air.

Another basic and necessary sensor is the oxygen sensor. This device measures the amount of oxygen in the gases coming into the exhaust manifold. If there is too much or too little oxygen, the sensor will send a signal to change the fuel to air ratio that is going into the piston chambers. Without the oxygen sensor, you would have an increase in emissions and less power.

Did you know your speedometer contains a sensor? This sensor sends signals about your speed to the ECU from the transaxle, where it resides. Without this sensor you would have no idea how fast you’re going, and if you’re like a lot of people, that feedback helps you stay alive.

There are a lot more sensors in your car, but not all cars have all kids of sensors available. There is a throttle position sensor, which provides feedback from the accelerator pedal to the ECU. The knock sensor detects vibrations in the engine. There are also sensors that detect crankshaft positions, air intake, and even a sensor that tells you a door is open on your vehicle so you don’t drive away with your door flapping in the breeze.

Often when something seems wrong with your car, it’s not a direct problem but an issue with a sensor. Sometimes a sensor can be dirty and not send the information it needs to send, or it can be faulty or damaged in some way. So if it seems like something is wrong with your car, it may be an associated sensor. Always have a qualified mechanic look at your sensors if something isn’t right with your car.