Hi all,

Don't usually post over here, but I'm having a terribly hard time sorting out this issue. I've got a persistant CEL, giving me code P0447 (Evaporative Emissions Vent Control Circuit Open, or something to that effect). I can clear the code using my IID tool, but it comes back upon the second startup. I've tried replacing the gas cap, as that seems to be a point of failure in the emissions system, but it did not resolve the issue. I've searched just about every forum I can find, as well as general searching, and reading through the shop manual, but no real solution has emerged. According to the tables in the workshop manual, P0447 is a fault to ground on the DMTL pump. Does this mean I should replace the entire charcoal canister/DMTL pump assembly? Or should I take it down and clean the connections, etc. first? I'm not really familiar with all of the emissions system stuff, so forgive my ignorance.

Thanks in advance,
Paul

 

Yep, clean up the electrical connections, and look for places rubbed thru insulation on the wires.

 

Great, thanks for the reply. I haven't dropped the spare to look around yet, but I assume the canister should be pretty visible once I do? Also, can I just use MAF sensor cleaner or something similar on the connections? Will probably give it a go on Wednesday after work since it's supposed to be a rare clear day here in Pittsburgh.

Thanks,
Paul

 

Seen a few DMTLs go bad in those vehicles. Make sure there isn't gas in it or else you need a tank too. Depends on if the tank was repaired under a recall long ago.

 

Dropped the spare and unbolted the charcoal canister for access today...I was able to get the electrical connector off, and sprayed it with some electrical parts cleaner. Cleared the code with the IID and did a few ignition cycles. Light is STILL ON.

I'm hoping that I don't need to follow the wiring harness through the whole length of the vehicle or something crazy. Any other obvious areas I should start with? I'm due for inspection in May, so I definitely need to get this figured out sometime soon. Leaving for a trip with the Rover Tuesday morning; fortunately, this seems to have no effect on performance.

Thanks,
Paul

 

I would be leaning towards the DMTL as well, and without the right tool, it's a difficult part of the system to test. But there is also a connector behind the RF wheel liner that I've had problems with for this, and other DMTL issues. Grey connector, rear part of the wheel well.

 

Just thought I'd post a quick update, since I'm still dealing with this...

Checked the wiring and plug for the DMTL pump and cleaned everything up, per a few suggestions - no luck.

Took the truck to the dealership and asked them to diagnose. Result was "you need a new charcoal canister. It's $748.19 (or something like that) including labor." No thanks. Found the charcoal canister online for $67.85, genuine part. Ordered and installed - no luck.

Spoke to the folks I ordered the canister from, and they think its probably the DMTL pump itself. Ordered one of those the other day, it arrived this afternoon. I'll be putting it on this evening and hoping for the best.

This is becoming quite the pain in the a$$, as PA state inspection will not pass a car with a CEL on, regardless of what is actually wrong with it.

 

Pvangura,
did you figure out the problem, i am throwing a P0447-open circuit code, has looked for a short in the wiring- no problems found. good gas cap. new DMTL pump installed. pump continues to run and pressurizes the system until the gas cap "burps" to relieve the pressure build up. Driving me crazy..
tim

 

what color are the wires coming off the grey connector, having the same problem the the P0447 code, new gas cap, new DTML pump, all wires look good under the mud deflector on the right front fender.
going crazy...

 

I was having this same issue on my 2006 Land Rover and was able to fix it. I found a post on a different site about a wire issue that was causing this code to appear, they fixed the wires and the code went away. I did exactly as they said and my code disappeared as well. The wires from the DMTL pump were rubbing against the frame of the car and were slightly cut. I followed the wire harness up the right side of the vehicle where I found a plug behind the right front wheel (you may have to remove the wheel and cover that sits behind the wheel to access it). That is where you will see the red ground wire that is rubbing against the frame. I repaired the wire, reset my codes, and drove around to test it out. It been almost a month and still no code.