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Discussion Starter #1
Check engine light (CEL) due to fuel cap leakage or something

Hi all,
A few days back my 2006RRS SC's CEL popped up and i got scared to see that. I read a few forums and figured out that it might be due to loosely tightened fuel cap. I tightened it and the next morning it disappeared. It happened a few time and as i tightened it it disappears. But after fueling it night before last CEL again appeared and after several attempts of tightening the fuel cap it has not disappeared. I dont know what to do and how to fix it. I am going on a month long vacation next sunday and dont wanna stay stressed because of the CEL. Help needed. HID ignitor last week and CEL this week. Should i try replacing the fuels cap?


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Re: Check engine light (CEL) due to fuel cap leakage or something

Gas cap is cheap insurance. Could be a failing seal, clogged vent, crack... Just replace it and be on your way. If it is not the cap at least you know it's fresh and good for another 8 years or so.
 

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Re: Check engine light (CEL) due to fuel cap leakage or something

How do you know that the CEL is on because of the fuel cap?
You can get an OBD2 scanner at CTC which plugs into a receptacle under the dash. It will tell you why the light is on.
 

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Discussion Starter #4
Re: Check engine light (CEL) due to fuel cap leakage or something

How do you know that the CEL is on because of the fuel cap?
You can get an OBD2 scanner at CTC which plugs into a receptacle under the dash. It will tell you why the light is on.
I think that it is the fuel vapor related thing because CEL always shows up after fueling and most of the time it disappears when i tighten the fuel cap so that all the vapors vent out from the nozzle that has the vapor sensing sensor on it. But I am not sure. I am scared to use the OBD myself as i dont have a clue on how to use it and where to connect it. And i read somewhere that plugging in an OBD could cause more problems. What do you think? I will try and replace the fuel cap and see what happens. Id be lucky if its just tht.


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Re: Check engine light (CEL) due to fuel cap leakage or something

Gas cap is cheap insurance. Could be a failing seal, clogged vent, crack... Just replace it and be on your way. If it is not the cap at least you know it's fresh and good for another 8 years or so.
Yea u r rite il just get a new one tomorrow and see what happens.


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Re: Check engine light (CEL) due to fuel cap leakage or something

If you've had a PCM software update since midyear 2006, when the vehicle detects a fault for a leak in the EVAP system(P0442 or P0455) it will show a message on the IP to alert you to check the gas cap. - most vehicles have had an update, if you haven't ever, you should for better fueling control, and to keep certain erroneous faults from setting.

Also, a fault with the EVAP system on this vehicle, is usually not the fuel cap, and when it is, it can be seen as a visual failure(cracking, splitting) of the seal.

It is a cheap part, but unless you can see something wrong, it is almost a waste of money on this model.
 

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Discussion Starter #7
Re: Check engine light (CEL) due to fuel cap leakage or something

No i dont think there is any visible damage on the fuel cap. The cap looks fairly new. So should I get an OBD2 and run a diagnostic on it? I dont have a clue how to use it. But lets see. Where does it plug in and does the obd2 have mating connector for this model.


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Re: Check engine light (CEL) due to fuel cap leakage or something

DLC is located under the dash, about where the driver's right shin sits. Plugs in vertically.

Pretty much just plug it in and it will tell you a code, write down the code(Pxxxx, description will vary based on scanner, but P-code will be the same) and report back.

Most auto parts stores will pull your code for no charge, and then offer up their suggestion of what part you should buy to fix it.
 

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2013-2015 Range Rover Evoque
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Re: Check engine light (CEL) due to fuel cap leakage or something

The scanner plugs right in as all OBD2 connectors or ports are the same. My L538 is throwing a P0089 code, which appears to be the fuel pressure regulator. The amber check engine light comes on intermittently. This is the only code when scanned. You can pull up all of the universal codes on line.
 

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Re: Check engine light (CEL) due to fuel cap leakage or something

Plug the OBD2 reader in, and then turn the key on. Not start, but just to the on position. The reader will show a code, which usually begins with a P. Post the code here to Roverguy7, or you can also type it into google.
 

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Re: Check engine light (CEL) due to fuel cap leakage or something

I'm having the same issue and after much research I've come to conclusion it is a failing DTML pump. Replacement cost is about $300 for the part. From others who've replaced, state it's relatively easy and underneath the right rear wheel well
 

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Re: Check engine light (CEL) due to fuel cap leakage or something

DMTL pump is one of the more common failure points of the EVAP system.

If you replace the pump, I would suggest replacing the Charcoal Canister at the same time. Use PN WTB500260, not WTB500292 (the 260 comes with a new pump) - check pricing.
 

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Re: Check engine light (CEL) due to fuel cap leakage or something

DMTL pump is one of the more common failure points of the EVAP system.

If you replace the pump, I would suggest replacing the Charcoal Canister at the same time. Use PN WTB500260, not WTB500292 (the 260 comes with a new pump) - check pricing.
hussy74, sorry to thread-jack but not sure if you're experiencing the same problem, so I figured Id ask here since its related.

RoverGuy,

Like the OP, ive received the "Fuel Cap loose or missing" for quite some time as well as a CEL. Some of my other symptoms include after filling up, a heavy gas odor the lingers for a couple days. I don't have the actual code off-hand but when I ran and OBD scan, and looked up the code it came back to an EVAP leak detection - which ultimately led me to a post the stated it was the DMTL pump. Today I happen to be getting an alignment - ironically after I posted in this thread - when the service tech pulled me in to the bay and showed me this;

IMG_20140318_130105819.jpg IMG_20140318_130115349_HDR.jpg

Gas leaking from underneath... Now this may sound like a dumb question but does a failing DMTL pump actually leak gas? quite possibly just a seal? hose? I didn't have much time to find the source of the leak while underneath but I can lift it up later tonight and look around. If dropping the tank is necessary, how difficult is it on my model; 2006 RRS HSE

If at all possible I'd rather repair myself unless you think its smarter to take it in to a mechanic.
 

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Re: Check engine light (CEL) due to fuel cap leakage or something

There is only one way I can see for the pump to cause that. The pump also contains the changeover(vent) valve, which is normally open. If that were to fail closed, or get clogged, and ambient temperature increased a good amount, you could end up pressurizing the vapor in the tank, and cause a seal to fail(haven't seen this, but I can justify it in theory) This should cause a purge valve fault (P0441) before a failure like this, especially before a P0442/P0455 fault.

More likely it is a liquid fuel leak, or at least liquid in the vapor system, but for there to be liquid fuel in the vapor system aside from after constant topping off of the tank, there would almost have to be something wrong internally. Also I could see a stuck open purge valve(which would give a 442/455 fault) causing too much vapor to be pulled into the charcoal canister when the vent valve is closed.

It doesn't look like there's any damage to the pan there, so unless something jumped up and carefully hit the tank you're probably not looking at damage.

There are two vapor lines on top of the tank, and one fuel line, along with the pump seal. Two lines connect at the front of the tank, and the larger vapor line(that goes to the DMTL) goes to the pump cap.

You can see a portion of the vapor lines if you remove the heatshield by the driveshaft. You may end up having to drop the tank to really see what's going on, as most of it is not visible, which on a lift isn't too bad, but I wouldn't want to do it on the ground.
 

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Re: Check engine light (CEL) due to fuel cap leakage or something

There is only one way I can see for the pump to cause that. The pump also contains the changeover(vent) valve, which is normally open. If that were to fail closed, or get clogged, and ambient temperature increased a good amount, you could end up pressurizing the vapor in the tank, and cause a seal to fail(haven't seen this, but I can justify it in theory) This should cause a purge valve fault (P0441) before a failure like this, especially before a P0442/P0455 fault.

More likely it is a liquid fuel leak, or at least liquid in the vapor system, but for there to be liquid fuel in the vapor system aside from after constant topping off of the tank, there would almost have to be something wrong internally. Also I could see a stuck open purge valve(which would give a 442/455 fault) causing too much vapor to be pulled into the charcoal canister when the vent valve is closed.

It doesn't look like there's any damage to the pan there, so unless something jumped up and carefully hit the tank you're probably not looking at damage.

There are two vapor lines on top of the tank, and one fuel line, along with the pump seal. Two lines connect at the front of the tank, and the larger vapor line(that goes to the DMTL) goes to the pump cap.

You can see a portion of the vapor lines if you remove the heatshield by the driveshaft. You may end up having to drop the tank to really see what's going on, as most of it is not visible, which on a lift isn't too bad, but I wouldn't want to do it on the ground.
Thanks for the explanation...

I'm getting 171/174/442 faults. I'm going to throw the car on jacks and remove the shield/cover hoping the cause is obvious from there. Otherwise, I think this repair might be best left for the pros.

This is frustrating as we just had the fuel pump replaced 2yrs ago...

Worse case scenario what am I looking at at an indy shop;,3-4hrs labor + parts? DMTL/Fuel Pump being the most expensive?
 

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Discussion Starter #16
Re: Check engine light (CEL) due to fuel cap leakage or something

I got it diagnosed and it shows P0441 EVAP code. Please advise on what to do now. The guy cleared it out for me but I guess this needs to be fixed.


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Re: Check engine light (CEL) due to fuel cap leakage or something

Google P0441 and there will be a lot of info on that code which is a generic code.
 

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Re: Check engine light (CEL) due to fuel cap leakage or something

441 code is incorrect purge flow, usually a bad purge valve, but I have seen other things cause it on this too. A restriction in the vent side of the system will restrict the purge flow.

Do some shopping for the purge valve, P/N MAP500100, prices nearly tripled on it a couple months ago, you might be able to find one for the old price still.
 

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Re: Check engine light (CEL) due to fuel cap leakage or something

Worse case scenario what am I looking at at an indy shop;,3-4hrs labor...
I think worst case would be the tank itself, cracked seam or something, but labor should be right around there for just about anything with the system. I would suspect a bad seal, either at the pump, or a pressure line.

Unless it is leaking a lot, as in puddle while running, I don't see the 171/174 being related.
 
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