What does having a faulty sensor mean?

I'm thinking about buying a car from a classmate but I know very little about cars. The owner said that the only problem with the car is that the check engine light comes on and off when the road is very bumpy. She said she took it to 2 different mechanics who both told her that nothing was registering with the computer and that it's probably just a faulty sensor. Does having a faulty sensor mean something is wrong with the electronic control unit as a whole, or is there a problem with a specific control? Also, how much do you think it will cost to fix that problem? Thanks!|||After reading the previous responses there's a couple things I'd consider. First of all, this is a low value car no matter how good a shape it is in or the mileage, and a difficult resell even without these issues. Secondly there is usually a separate check engine light, and ABS light, however on cheaper vehicles, like hyundai and kias, that had the option to not have ABS (Active Braking System), there sometimes isn't a separate light for that. The mechanics would be checking the computer for your engine when really your problem is with your ABS system, which generally a dealership can scan and tell you what is wrong.





My advice, take the 2k and buy a different car like a GM or Ford product, as the parts and repair is cheap and more common, or a Honda if you can find one that has been well taken care of.|||OK lets take it from the top. Do you like this car? A faulty sensor is kind of an idiot light . You can do fine without it as long as you check your oil and radiator fluids frequently. You have the advantage of lowering the price because of the questionable mechanics. But if you just want to drive and not check under the hood everyday, this car may not be for you.|||Like someone else said it is prob. a loose connection on a sensor, you could unplug and replug all the sensors you can find, then check the computer, some sensors are only 20.00 and others are $200.00, its hard to tell which one is setting off the light, even the transmission has sensors, so if it runs fine it may be worth buying if the price is right|||First of all, most check engine lights are an indication of a problem in your emissions and drivabilty portion of your car.Next , if a mechanic has used a scanner and retrieves no codes, this is called a hard code, " loose wire or a blowen fuse and last a manufactures recall.





Check it out, good luck Mrgreg1|||a vehicle has many sensors.


it's hard to pinpoint your problem.


a sensor costs give or take $200.00 not including labor.


and usually, when you change one sensor, you might as well change the other sensor closeby.


but, all in all, it depends which sensor is giving you the problem.


not enough info from what you describe.


you may not pass the smog test.|||problems on a bumpy road sounds to me like it's a loose connection in sensor/wires somewhere. If the car is older, probably some corrosion.





I would almost suggest going to a really bumpy road and see if you can get the light to stick on, then have it tested. But if it is something essential that pops off, I would hate for you to get stranded. CEL (check engine light) is nothing to mess with. You gamble on it being nothing serious, because if it is serious, you're screwed anyway. I would not buy this car until someone finds out what is throwing the CEL on.





does the light go off when the bumps stop? does the car have difficulties when the light is on?


it could be very minor or very big, so get more info first.