3 Frustrating Sensor Problems Common On Many Cars

Modern cars rely on a mind-boggling array of sensors to read everything from the mass of air entering the engine to the position of internal engine components. If you think of your car's computer as its brain, then the sensors are its eyes and ears. Without input data from these sensors, the computer cannot make the correct decisions to keep your car running efficiently and reliably.

Of course, anyone who's owned a car manufactured in the last several decades understands that sensor failures are all too common. Faulty sensors will usually trigger a check engine light, but they also produce various drivability symptoms. Below you will find three common sensor failures that can occur on nearly any car, along with the trouble they are likely to cause.

1. Throttle Position Sensor (TPS)

Despite the name, your throttle position sensor doesn't measure the position of your accelerator pedal. Instead, this sensor indirectly measures your request for acceleration by checking the throttle plate's state in the throttle body. Your car's computer then uses this information to control your fuel injectors and maintain a proper stoichiometric fuel to air ratio.

A TPS that provides inaccurate readings can result in poor idling, reduced acceleration, and even misfires. Without knowing the throttle's current position, your car's computer will not be able to inject the correct amount of fuel, potentially resulting in rich or lean running conditions.

2. Coolant Temperature Sensor

Although you need your car's coolant to keep your engine within its standard operating temperature, there's more to your cooling system than unrestrained coolant flow. Your ECU monitors your coolant temperature, adjusting various parameters based on whether your engine is too warm or too cold. This data is necessary for everything from transmission performance to auxiliary fan control.

A bad temperature sensor should typically trigger a check engine light, but you may also notice reduced performance or decreased fuel economy. Since your engine must reach its operating temperature to perform efficiently, cooling system issues often have a noticeable impact on fuel consumption.

3. Oxygen Sensors

Almost everyone has experienced a check engine light triggered by a faulty oxygen (O₂) sensor. These devices measure the oxygen content in your vehicle's exhaust stream, which your car's computer uses to measure combustion efficiency. Without this reading, your computer will not be able to appropriately adjust the fuel injection rate to account for lean or rich conditions.

O2 sensors usually trigger check engine lights before they produce noticeable symptoms, although you'll likely have lost some small amount of fuel economy by this point. Over time, symptoms will usually progress to rough idling and noticeably reduced gas mileage.

If you have additional questions, reach out to a local car repair service.

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