Loose Gas Cap = Check Engine Light

[foxmajik]

Today on the way home from work the MIL (check engine light) came on in my car.

When I got it home the first thing I did was call the dealership to ask them if they could look at it. Of course they told me they were closed today.

So I thought I'd have a shot at diagnosing it myself.

I got out my trusty ELM327 OBD II to USB adapter and plugged it into the diagnostic port, then started up scantool.net's scan tool software.

When I read the scan codes from the ECU I got a code of P0455 (Generic Evaporative Emission System Leak Detected [gross leak/no flow]), which I looked up on Google, where I located this article.

I knew I didn't have any of the testing tools but I read through the article anyways, which informed me that one of the first things I should check is "a loose, incorrect, missing or damaged fuel fill cap."

I checked the gas cap and found that it was loose, so I screwed it back in.

I knew from pervious research that the ECU would turn on that DTC code if the engine was started twice while the problem still existed, so I started and stopped the engine three times to verify the check engine light wouldn't come back on.

EDIT: This problem was fixed in the 2009 model, it has a loose filler cap indicator on the console.

[tomFS08]

Thanks for the info.

-Tom

[foxmajik]

Hey guess what, in the 2009 fortwo they put in a light on the dash to tell you if the gas cap is loose.

I can't imagine any more sound acknowledgment of a problem than putting an extra lamp on a new model to help the owner fix the problem so I don't understand why there has been no offer to fix the problem for owners of existing 2008 year model cars.

[Dave777]

Originally Posted by foxmajik

.

I don't understand why there has been no offer to fix the problem for owners of existing 2008 year model cars.

I sincerely don't intend to sound sarcastic, but I have to ask what you expect the dealer to do to "fix the problem?"

It's a loose gas cap. Happens to good people who own every kind of car out there. They get the same check engine light and from then on they make sure they screw the cap on until it clicks. Problem solved.

[Jordon]

Originally Posted by foxmajik

Hey guess what, in the 2009 fortwo they put in a light on the dash to tell you if the gas cap is loose.

I can't imagine any more sound acknowledgment of a problem than putting an extra lamp on a new model to help the owner fix the problem so I don't understand why there has been no offer to fix the problem for owners of existing 2008 year model cars.

What do you expect, smart to call and have you bring the car in so they can change the cluster to include a new light, reprogram the car to turn that light on instead of the CEL, just so you can fix a problem you caused yourself and not take it back to them. FYI, most manufacturers will only cover checking the light once for this, if you go in a second time they will charge you.