I got the dreaded Check Gas Cap message, CEL and code P0445 (is that right, or was it P0455, I can't remember right now) -- I checked my gas cap, seemed to be ok. I read through all the threads on this site about this issue and decided I needed to order some parts! I took my gas cap off, twisted it back on nice and tight, and the Check Gas Cap message went away, the CEL went out a few days later (I was going to clear it but decided to wait and see what happened) and I've been driving without the message or CEL for several days now.

I might order up a new gas cap, but for now I don't seem to have any problems.

Just wanted to bring this up -- if you get the Check Gas Cap message, unscrew the cap and twist it back on nice and tight. That's what worked for me, at least for now.

 

Oil the gasket on the cap. If they stick and bunch up a bit it can cause leaks in the evaporative emissions system.
Also shut off the engine when refueling.

 

sometimes that happens, just have to take the cap off and snugly refit

 

I have a 2007 Honda Ridgeline that gives that message on any day that there is more than a 30 degree temperature swing - its very predictable. First time it happened when it was brand new and under warranty the dealer just cleared the code and said to bring it back if it happened again. After that, I read on the Honda forum it seemed well-documented that it was due to pressure changes in the tank and to just ignore it. I don't know if the Jaguar system can be triggered similarly, but it makes me want to ask - what was the temperature there in the 8 or so hours before this happened?

 

The first time it happened was just as I was getting home from an all day road trip -- drove from central Georgia to Miami and then to West Palm Beach with only a couple stops for gas and you-know-what. The temp? HOT AS BLAZES - this IS Florida. I turned the car off and it did not come back on the next time I turned the car on (later the same evening) -- it did come back on the next day after sitting in the garage over night and driving it about 2 miles, and then it stayed on. I had already tried to tighten the gas cap before driving it. When I got home, I checked the OBD code and then I put it in the garage and then before driving it the next day I took the cap off and twisted it back on real tight. The CEL stayed on for a few days but the message (Check Gas Cap) was not displayed. It's been fine ever since.

Ross1 -- thanks for the tip about oiling the gasket, I'll try that!

Pdupler -- I had an '06 Ridgeline that would tell me I needed air in the tires whenever the temps went below 60 degrees! Very annoying, but I loved that truck, wish I still had it!

 

Mike,

Did oiling the gasket solve the problem?

I am having this issue on the new XJ8. The rim where the gasket mates with the filler neck is rusty. I am oiling and wire brushing to clean that too.

Thanks.

 

I haven't had the problem since I cleaned the gas cap (can't remember if I oiled it or not, but probably ran a bit of WD-40 around the gasket) - I keep it clean, and make sure it's fitted tightly after fueling.

 

Gentlemen,

I had the same problem on my XJR 100 today. I had the car on jack stands for 3 weeks while i was changing suspension parts. When I took it for a test drive today, I had "Check Gas Cap" and CEL come on. I checked the cap, checked the hoses going into the gas tank, fuses (both in the trunk and under the hood) and couldn't find anything suspicious. I read that some guys are not able to put gas in the tank when they get "Check Gas Cap" message due to Canister Close Valve. However, this wasn't the case with me. I was able to fill up full. Later in the day the "Check Gas Cap" message went away and I just have CEL on now. So I'm not sure what I should look for to fix it. Any help please?

Dan

 

check the hoses between the canisters underneath near the rear suspension

numbskulls who did the fuel pumps left them undone on mine

 

Thanks for the advice, I will check today. However, what bothers me is that I haven't touched the rear of the car at all...All suspension work as performed on the front. So I don't really get what could've caused the hoses to disconnect.

 

Did you have a strong fuel smell, drop in fuel economy, and lack of power under WOT? I've had all of the above since having the fuel pumps replaced in mine. I haven't been able to bring it back to the shop, as I am one of those idiots who use a Jag as their only means of transportation... lol.

 

Hmmm. You might just try cleaning the cap and rim and oiling gasket.

Then just reset CEL.

See if that works first.

 

I think you're right, RobertJag. I might be overthinking the whole thing, so I ordered a new gas cap from the dealer and cleared the code. We'll see if this does the trick. I'll let you guys know on monday. have a great weekend.

Dan

 

if the new gas cap doesn't clear the code replace the canister close valve. Its an easy 10 minute fix. Jack up the right rear and slide face up under the right rear door. The canister is just inside and to the front of the rear wheel. One bolt and one connector and you've replaced it. Since it lives among the spray and muck it is the most prone to fail.