2007 Yaris Engine Light

Hi, We purchased a 2007 Yaris hatchback on August 25, 2006.

Mileage has been in the 38 to 41 mpg range.

We are presently at 2,996 km on the vehicle.

Filled up the vehicle two days ago.

No problems with the vehicle, but today the engine light came on while driving home from work.

Called the dealer, who said that the gas cap was not on correctly. Turned the gas cap, and it clicked. Dealer said the engine light will reset itself in a couple of days.

All fluid levels are okay.

Has anyone else had this problem on such a young vehicle?

Thanks,

Joe Ontario, Canada

Reply to
jcaverly
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The problem is not with the vehicle, it is with whoever filled up with gas. The gas cap should be tightened until you hear it click several times or you can get a check engine light. Loose gas caps are probably the leading cause of check engine lights on new vehicles because people miss the part in the owner's manual about properly tightening the gas cap and miss the instructions on the gas cap itself to tighten until you hear it click several times. I think a lot of people worry about breaking something or over-tightening the cap but the clicking you are hearing is normal and does not mean that the cap is over-tightened.

The gas tank is designed to prevent gasoline vapor from escaping into the atmosphere. The computer checks whether the gas tank is sealed tight by letting a vacuum build in the tank. If it won't hold a vacuum then the computer will turn on the check engine light.

Reply to
Ray O

It's not dependant upon the age of the vehicle. It's a result of the pressure in the gas tank not being what the sensors expect it to be. I wonder how the dealer could tell your gas cap was loose from over the phone? Those new-fangled cars are amazing, aren't they?

Reply to
badgolferman

Did you read the owner's manual of your shiny new $15,000 car?

No?

Why not?

The answer is.....in the owner's manual.

Reply to
Elmo P. Shagnasty

My guess is that you failed to secure the gas cap fully. THIS IS A COMMON PROBLEM, do not stress over it.

Go to any Autozone store. They will allow you to use the scan tool and you can confirm the code is in the range of P0420 to P0459. These codes deal with the Evaporative Emissions Control System, and I don't recall specifically, but I'm pretty sure that P0420 is a gross leak or a system malfunction. (It is one or the other, not both.) Either way, if the gas cap is not secure, the system will detect the leak that results.

You CAN wait for the light to reset itself, but I like to reset the light myself because then I can confirm what I think the trouble is.

Autozone will be happy to sell you a scan tool, but you can check one out -- just like at the library -- and use it yourself. In some states, the store clerk will use the tool in your presence, in Calif., they will let you use the tool yourself. Jot down the code that is displayed, then if the light comes back on, you can compare the new code with the one you get now.

Reply to
Jeff Strickland

Diagnostic trouble codes (DTC) P0420 through P0434 have NOTHING to do with the evaporative emissions control system, and AFAIK, DTC P0435 through P0439 and P045 through P0459 are unassigned.

A loose gas cap will most likely cause DTC P0442 or P0455. If the code is something other than P0442 or P0455, then the identified system should be checked out.

Reply to
Ray O

anything made since 1996 is going to have that kind of issue. my scion cap requires one click.

they *should* have reset the light if they went to the trouble of plugging the codereader in- its a matter of pressing one button.

Reply to
mike

Sorry, that's P0440 to P0459, not P0420 through P0459. Sorry for the confusion.

I would NOT check anything on a brand new car. I'd check the codes, and if in the range of P0440 to P0459, I would make sure to secure the gas cap and reset the codes hoping that they did not come up again. If the codes are outside of the range 440 to 459, then I'd take steps to check the car out. Given the explanation of the OP, my money is on a unsecure gas cap, not on a malfunction of the vehicle systems.

My reference material tells me that a gas cap can manifest itself as P0440, a simple malfunction, P0442, a small leak, or P0455, a gross leak. I'd hazard a guess that a P0446, vent circuit malfunction, is a possible symptom as well.

In any case, given the symptom the OP gave us -- the check light came on soon after buying gasoline -- I have no problem suggesting he tighten the gas cap and reset the code and do nothing else. This seems to be the same advice his service advisor gave him ...

Reply to
Jeff Strickland

Hi, I hooked up a digital OBD2 tool, and discovered the code for the problem;

P0456 - Evaporative Emission Control System Leak Detected (very small leak)

The red led comes on, and it will not let me erase the code so that the engine light goes out.

As the dealer said the the gas cap was loose, this would have been a P0457, which it is not.

I have filled up with fuel since the light came on, and have ensured that the gas cap is indeed on correctly.

Joe

Ray O wrote:

Reply to
jcaverly

Here are some pages from a Tacoma repair manual for DTC P0456:

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In the factory repair manual Toyota lists possible causes in order of likelihood, and loose gas cap is listed first.

A gas cap that is not quite tight enough might trigger DTC P0456, while a cap that is off or very loose would cause P0457.

In any event, if the gas cap is tightened enough so that you hear it clicking or ratcheting several times, the check engine light should turn itself off. If there is a leak in the evaporative emissions control system, the check engine light will remain illuminated.

Even if there is a leak in the evaporative emissions control system like a bad gas cap, the OBD II scan tool should be able to turn off the check engine light until it detects the problem again. Try pulling and then replacing the EFI fuse to clear the codes.

If the light comes back on, you should explain to the dealer service dept. that you tightened the gas cap until it clicked several times, cleared the code, and the light still came back on. You want them to document the condition in writing so that you have a record.

Reply to
Ray O

This isn't limited to Toyota.

I work for a company with a large (50,000+) fleet. This same "problem" shows up on GM, Ford, and Chrysler vehicles.

I'd trust the dealer, tighten the cap, and get on with life.

Reply to
Bonehenge

The Society of Automotive Engineers (SAE) has standardized trouble codes and their possible causes for the OBD II system. For most trouble codes, no matter which automaker, the cause will be the same.

Reply to
Ray O

I purchased an 07 Yaris Liftback in September and mileage has been around

34.5 with mostly city driving. I can understand the gas cap thing as it is different from the 3 clicks most vehicles use. This vehicle has been perfect. Mine is an automatic.
Reply to
Bob Palmer

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