I have a 2001 Toyota Prius, and the "check engine" light went on. What are common causes for this?

Question

I called the dealership, and they can't see me for a week, is it dangerous to drive until then?

Answer 1

Well, the answer depends on whether anything else has been happening with your car. Other than the light, are there any odd sounds, smells, behaviour? If the car is acting strangely, then stop driving and get thee to a dealer. Otherwise, you can wait the week.

Most common cause for a check engine light is usually the gas cap not being tight enough. Reseat the gas cap. Although in the past year a few 2001s have been throwing a code or two that requires a new ECU (one of the computers) to a newer revision.

If it's transient problem (such as that gas cap), if it doesn't occur again within about 3-4 restarts of the car, the check engine light will go off on its own.

Since you have a 2001, you're out of factory warranty, and even the Toyota extended warranty doesn't cover diagnostic charges (labor to hook up the THHT/ODB-II tester) to read the codes... Best bet is to find an auto parts store (like Autozone) - they'll often read your OBDII port to check for check engine light codes for free, in the hopes that you'll use them to buy the replacement parts. But certain codes are common and may be covered under the hybrid or emissions warranties which should still be in effect (depending on your mileage).

Starting the car and changing gear before the READY light goes on may also leave a check engine light.

Once you get the codes, post to one of the Toyota Prius owner's groups below, and we can point you in the direction of what the problem is and how to get it fixed.

Answer 2

There are any number of causes for it -- a bad oxygen sensor is common, but it's foolish to ignore it, as one reader suggests. You can cause emissions problems with your car even if it still drives fine.

The light comes on when the computer in the engine records that there is a problem registered by one of the many sensors in the car. The first thing the dealer will do is connect a code-reading device to the engine computer and find out what the engine computer is recording. They'll use that as the first step to diagnose the problem.

If you don't want to wait a week, find a mechanic and ask if they can read the code for your car. If the mechanic can diagnose it, he/she can probably fix it, and probably will charge less than a dealer (I assume you don't still have a warranty on a 2001). Is it dangerous? Not for you (unless there are other warning lights on that you haven't mentioned), and probably not for the car, but the mechanic can tell you for sure. You can find customer testimonials about mechanics near you at the Car Talk web site.

Answer 3

Well I know that a common thing that can happen is if you go and fill up your car with gas and don't secure the gas cap, the check engine light can go on, causing a false read for the light to come on,thinking that something is wrong with the car, when in fact it is nothing.. If you have filled up your tank in the last few days, that could be it..

Answer 4

Take it to Autozone or Pepboys or something like that, and they will plug something in to the computer and tell you what wrong for free in about 3 minutes. Chances are it's the O2 sensor, any car over 100,000 miles will usually have wore out o2 sensors. to repair it will cost about $120. it not dangerous to drive it til you get it fix, but your gas mileage MIGHT, just might, be a LITTLE under the norm.

Answer 5

When it came on in my car it turned out to be an oxygen sensor went out. 2 years later and I still haven't had it replaced. It didn't affect the way the car ran at all.

Answer 6

common thing is the sensor for toyota. change the sensor and you will be fine. (but may cost some money)

For American car especally dodge., that check engine will always be tramisssion problem (that will cost lots of money)

Answer 7

Own exactly the same model light has been on for 5 years, don't worry.

Answer 8

simple ur drivin a toyota

Answer 9

Go have the OBDII read.

Answer 10

did you look in the owners manual ......duhduhduh