Skip the auto shop - Our mechanics make house calls

Q: What Sensors Do All Cars Have and What Optional Ones are There?

asked by on

What Sensors Do All Cars Have and What Optional Ones Are There?

There are at least 40 different sensors that most vehicles have today. I will have to subcategorize them into four categories: engine, transmission, interior comfort, and safety

All vehicles produced today use multiple computers to help with emissions, fuel economy, and safety features. It will be hard to explain all the sensors if you don’t understand that there are several different computers in today’s vehicles that have to talk to each other within increments of milliseconds. Each of these computers are for different areas of the vehicle.

These computers are for the 4 different categories I have mentioned above. They are networking together with something called a CAN bus system, which is a network of wires and fiber optic cables connecting one computer to the other. If these computers didn’t communicate to each other then vehicle wouldn’t be able to function.

To make all of this happen together like a well choreographed dance show, the computers rely on data from various sensors in the vehicle. All these different sensors use different voltages, amperages, and ohms.

Let me start with the engine sensors which are among the most complicated:

All these sensors work with the transmission sensors and with the interior comfort sensors to make sure the vehicle runs smoothly. There may be more sensors than what I have listed depending on the make of your vehicle.

The reason that the engine sensors work with the interior comfort sensors are to help put power to the engine when it needs it for acceleration, or for safety reasons such as a battery issue so you don’t get stranded on the side of the road.

For example, if you press on the throttle really fast, the engine computer (PCM) may actually shut off your air conditioner, which is controlled by the body control module (BCM), to be able to gain more engine power until you reach your desired speed. If you were to disconnect one of these sensors, the engine will either not run or run so poorly you would hate to drive it. Also, if the alternator goes bad or your charging system goes bad while you are driving the computers will network and turn off all accessories to help get you off the road safely rather than let your engine die in the middle of the road.

Transmissions in today’s cars also have sensors on them to control fluid temperature and how the transmissions shift into each gear and how smoothly it achieves this.

Other sensors on the transmissions control your speedometer, AWD, and help your antilock brake system if equipped. These sensors are nothing to fool with and should always be checked or replaced by certified technicians.

The sensors most people want to disconnect to try to gain horsepower are the emission sensors and depending on which state or country you live in this could be illegal and pe punishable by fines or worse. I do not recommend disconnecting any of your emission sensors on your vehicle. If you have any questions on how something works or your looking at putting on aftermarket performance parts seek some help from a mechanic and do your research on what is legal for your state.

Was this answer helpful?

Need advice from certified mechanic? Get help now!

Over 1000 mechanics are ready to answer your question.
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

Ask a Mechanic
(100% Free)

Have a car question? Get free advice from our top-rated mechanics.

Ask A Mechanic
Over 10,000 questions answered!

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Fair and transparent pricing

Get a quote

What others are asking

Q: Ambient temperature sensor is said to be bad..clutch will not engage.

The A/C compressor clutch is turned on and off by the clutch relay in the intelligent power module on left side of engine compartment. The relay is turned on and off by the engine power train control module. If the...

Q: Ford Taurus stalls while accelerating

Realize that modern cars are really complex. Even though that car is 15 years old, it's still a pretty modern car. There are all kinds of data, that’s hidden inside the computer. You get a mechanic like me, any good...

Q: The engine stalls under acceleration

This may be a sign of a failing throttle position sensor. The throttle position sensor (TPS) is a sensor used to monitor the throttle position of the throttle plate inside the throttle body in relation to your foot position on...

Related articles

P0240 OBD-II Trouble Code: Turbocharger Boost Sensor B Circuit Range/Performance
P0240 code definition Turbocharger Boost Sensor B Circuit Range/Performance What the P0240 code means P0240 is an OBD-II generic code triggered when the Engine Control Module (ECM) detects the intake boost...
Rules of the Road For Iowa Drivers
Driving on the roads requires knowledge of the rules, many of which are based on common sense and courtesy. However, even though you know the rules in...
What are the Car Pool Rules in Hawaii?
Hawaii is widely regarded as a land of vacation and relaxation, and as such, its scenic roads and routes are far better known than the state’s freeways. But, as with all...