Back to all

Not-So-Common Sense (Sensor Failures)

March 8, 2020

So your vehicle won't start.  What's the first thing that comes to mind?  Battery dead? Starter motor worn out? Out of gas?  Well, those are all reasons that make sense.  But your vehicle may be refusing to start because one of its computers is being warned that to do so might damage it.  Here's how that works.

You have lots of computers in your vehicle.  They need to know the status of things so there are several sensors monitoring various things going on.  These sensors send information to the computers that adjust the fuel and air mixture so you don't waste fuel.  They know when things aren't quite right and prevent you from starting your engine if that's going to damage it. 

Other sensors make sure the coolant is the right temperature, check to see you are not polluting the air and make sure other electronic components are performing their tasks correctly.

Here's an example of a sensor doing its job.  Your engine needs oil to lubricate metal components so the friction doesn't damage them.  Your engine has an oil pressure sensor that tells a computer called the Electronic Control Unit (ECU) if things are good to go or if there's something wrong, maybe the oil pressure is too low to keep things lubricated.  If it is, it gives a signal for the vehicle not to start, protecting the engine. 

Of course, the sensors can go bad, too, with some of the same results.  And so someone has to figure out if it's the sensor that's failed or if it really has detected a problem.  That is the challenge for technicians with specialized equipment to decipher the signs.  If a bad sensor is found, it may need to be replaced.  Sometimes a thorough cleaning can do the trick.  In either case, your service facility can track down the problem and get you back on the road.  Makes sense, doesn't it?

Tuffy Tire & Auto Service Plainfield
23846 W 135th St
Plainfield, Illinois 60544
815-436-1337

More articles from Tuffy Plainfield

Cabin Air Filter and Engine Air Filter: What?s the Difference?

October 12, 2025

You may have heard someone say they just got the air filter replaced in their vehicle. But did you know your vehicle has two different major air filters and they both perform quite differentbut very importantduties? Todays vehicles have a cabin air filter, and an engine air filter. The engine a... More

Timing is Everything (Timing Cover Replacement)

October 5, 2025

Theres an important part in your vehicle that shields your timing belt, timing chain or cam belt from the debris and gunk that can be kicked up from the road. Its called the timing cover. Its important because the timing belt or chain is what coordinates parts of your engine called the camshaft... More

Don't be Fuelish (Signs Fuel Pump is Failing)

September 28, 2025

A driver of a large SUV loaded with equipment was heading on a 7-hour work trip when he stopped at a gas station to refuel. When he went to restart his SUV, it turned over but wouldn't catch. Try as he might, he was never able to get it started again. Of course there are many things that can c... More