I've had this warning ever since I purchased the car. I've looked at all the hoses and can't seem to locate the leak. If I had a purge valve malfunction wouldn't the code tell me purge valve?
This may not have anything to add to the system but while at idle with the oil cap off I have no vacuum pulling into the valve cover. Gross air leak? The code is gross air leak.
Also, I have a leaky engine from underneath and can't seem to identify where oil is leaking. Replaced valve cover gaskets. I've posted questions to the oil before on here. I guess one of my questions would be if I have a gross air leak and no internal vacuum could the engine be forcing oil out where ever the weakest link is. The harder I run the engine the more oil seems to leak out. I'm shooting in the dark for answers and wracking my brain to maybe fix everything with a simple solution. EGR? PVC? Bad purge valve? I did put plastic over fill opening and put gas cap back on, cleared code and code came right back on. Maybe someone has a bit of input of where to start. car has 73000 miles and all hoses look good. I haven't noticed any bad hoses anywhere.
Thanks to all and Happy Hollidays! Stacey

 

Stacey,

What are the DTC codes numbers you have?

If it is the EVAP system they range from P0442 to P0455. The P0455 is for a large EVAP leak.

Could be valve failures, wire short circuits, pipes’ leaking etc

Do you get any P0171 or P0174? Aside from the usual air filter, bad MAF sensor and air tunnel holes, it could be on the fuel delivery side. Ie Bad fuel pump, blocked fuel filter, bad injectors etc.

Share the DTCs for more info

 

my only code has been po445.
When I say internal engine vacuum, I've always heard if you take off the oil fill cap, you should have vacuum pulling inward . I have none. Maybe I should rev it up and see which way the air flows.

 

Standard answer for this is to do a smoke test. Normally, there is an access to the system, a shrader valve with a green cap somewhere. I believe you are supposed to take the valve core off and inject smoke to show the leak(s). There are 2 short rubber hoses to those 2 big canisters by the gas tank that have been reported cracked before. That evap system has seen several revisions over the years, so hard to be specific.

For the smoke generator, you can find them on eBay/Amazon, or you can build your own with an old soldering iron burning baby oil on an rag in a can, and a bicycle pump to generate pressure.

Best of luck, keep us posted.

 

Stacey,

+1 to Fmertz's suggestion.

Some things to consider below for your DTC P0445, from the Jag AJ27 ECM DTC guide, which shows a possible cause of an electrical short.



Also I attach a pic of the entire EVAP system, for a NA engine. It could help you track down what could be a broken pipe.

A common problem is the Purge Valve (finding the right replacements part seems to be hard - as Fmertz mentioned there seems to be many different system parts in our cars - our Texan Statesman BCP had major problems finding the right parts).

There's even a YouTube video from our Rev. Sam showing the R&R which might be helpful. Link below.

Good luck.

 

There is a thread (as always) and a TSB (303-63 for me, see thread for the later one)

https://www.jaguarforums.com/forum/x...fusion-179542/

I recently needed to replace the purge valve (for 1999-2002 through A30644) since it was leaking. The original part (LJB1515AA) is not available new, but there is a new part (LJG1515BB) requiring a small 'improvement' of a vent into the box that holds the brake booster. I jury rigged this with a fuel filter, hose and cable ties, though I eventually got the actual parts (DAC4062 for the air filter) and (UKC6683 for the fancy cable tie) that I haven't put on. The jury rigged solution looks better, IMHO than the Jag solution. The new evap valve is widely available. Such as

https://parts.jaguarlandroverclassic...rol-valve.html
or
https://parts.harperjaguar.com/oem-p...alve-ljg1515bb

This may require an update to your ECM. For some reason, I did not need this, so my ECM may have already been updated with no note on the car.

Note: Rev Sam's video is helpful, but I found it to be very easy to turn the front wheels to the left stops, take the wheel well shroud out, and work on the evap valve without jacking or removing the tire, even with my relatively large torso. Videoing would be more difficult, but saves some time in practice if you're not doing that.

 

Hi Stacey,

The excerpt that David posted from the Jaguar Diagnostic Trouble Code Summaries is very important, because it shows that on your Jag the most likely cause of P0445 is an electrical problem, not an air leak. Generic OBDII scanners give you the generic definition of a code, but the Jaguar definition may differ, so that's why it's always important to consult the Jaguar documentation. You can download the DTC Summaries at this link, courtesy of our member Gus:

Jaguar X100 AJ27 DTC Summaries 2001 On

Regarding vacuum at your oil filler cap, on modern Jaguar engines the crankcase vacuum is managed to be "slightly negative" for various reasons, including improved power and fuel economy, reduced leakage from oil seals, etc. If the crankcase breather system is working properly, you won't feel a strong vacuum at the oil filler cap, though your idle may become rough due to the intake air leak it creates.

Cheers,

Don

 

Up date on loose gas cap. I had car up on blocks took all four wheels off and checked entire evap system front to back. Nothing broken or cracked or loose. Pulled tubing from canister and blew into it and tank holds pressure. Vacuum lines to purge valve pulling good vacuum. If the solenoids aren't working properly it would probably send a code,, right? I don't know if you can test the solenoids.

 

Hi Stacey,

As I mentioned earlier, the Jaguar definition of P0445 does not indicate that you have an air leak or loose gas cap. It indicates that you have an electrical problem, either with the EVAPP valve or with its wiring. Possible causes could include a short in the wiring or failure of the EVAPP/Evaporative Emissions control or purge valve. The valve is behind the left-hand front wheel arch liner. The valve should have battery power on the White wire with Purple stripe, and the ECM provides a ground on the Purple wire with Yellow stripe. If I recall correctly, the ground connection is pulsed, just as the fuel injectors are. If your meter has a duty cycle setting, you may be able to monitor the ground pulse, or if your meter can't read duty cycle, try the AC voltage setting to see if you get some AC voltage across the valve's electrical connector. You can test the valve by very briefly connecting a 9V battery to its terminals and listening for a click. You can also disconnect the hoses at the valve and blow through the valve to see if it opens and closes when 9V is very briefly connected to its terminals.

Cheers,

Don

 

Thanks Don! Next time she is off the ground I'll give it all a go.

 

I found the large air leak that has been throwing a evap code. I took the purge valve out of the fender and hooked up an air hose to the line that goes to the rear of the car. Supplied minimal air and heard large air leak at passenger side charcoal filter area.
Here is where I'm stumped. Center of car at rear there is a purge valve that looks to combine both canister vent hoses and a third hose that travels to the passenger shock tower that leads into the abyss. Inside the shock tower is where my air is leaking!
I have had the code and the marquee that says loose gas cap for months. I went to clear the code and this time code reader says canister purge valve faulty.
Any idea where I can find this part? Thanks, Stacey
PS Where is this hose leading that goes into the shock tower? It's a big size hose. Garden hose size.

 

Hi Stacey,

As I think I have mentioned, according to the Jaguar documentation the code you had, P0445, does not indicate an air leak. It indicates an electrical problem. By testing for an air leak, it is possible that you caused one.

Here is the diagnostic procedure for P0445 from the Workshop Manual:




You can download the manual here:

Jaguar X100 Workshop Manual 1999-2002

Since you did not previously find a leak, it is possible that by applying pressurized air to the system you caused a leak. Smoke machines and other leak detectors designed for testing the EVAP system limit their gas pressure to around 1 psi or less (typically measured in inches of water, such as 13 in. H2O, which is less than 0.5 psi). If you applied more pressure than that, you may have damaged the system, which is made mostly of plastic that becomes brittle with age. Note also that it is recommended not to inject oxygen (air) into the EVAP system due to the flammable fumes it contains. For safety, professionals use an inert gas such as nitrogen or argon.

Since you describe your hoses as large, I assume your car is equipped with the On-Board Refueling Vapor/Vapour Recovery (ORVR) system. You can view the parts diagram at this link:

Jaguar X100 ORVR Parts Diagram

The Purge Valve is Part 21, the Canister Control Valve is Part 7:



Cheers,

Don

 

Replace the Part Load Breather pipe (this runs from the Part Load Breather near the front left hand side valve cover to a tee at the throttle-body and from there to the purge valve, a vacuum line to the purge valve runs along with it through heat shield tape.).
It runs under the intake manifold so attach some string as a pull line before you pull it back towards the throttle-body, and use this to pull the new one through to the front.
Most of this pipe is corrugated plastic and gets brittle, it can be cracked many places, and will cause this exact fault. And, if it has not been replaced it needs to be, eliminating a source of vacuum and evap leaks. (I repaired mine only to have it break at another location, it must be replaced)
I found it also helps to apply a little smear of silicone grease to the gas cap seal.

 

Don, thanks for your photo's and link to the manual. In your photo, part # 7 canister vent solenoid is bad. Replaced it and all is good. The vent valve was dead in the open position causing a large air leak.

Thanks, Stacey

 

So, to make this clear, you did not have EVAP valve electrical issues (did you test EVAP fragged or EVAP short to ground)? And you have been through the relevant drive cycle (i.e. EVAP cleared, not just code reset)?

This result is a bit surprising to me.

Note added: Seems like you should have had a P0446 and/or P0447 if the canister vent valve was fragged, odd.

 

Glad that worked, a few days of driving will confirm it.
The canister vent solenoid valve is easy to remove, easy to test, and unless severely rusted / corroded, usually easy to clean up & lube, which is all there is to fixing it if the coil & spring are good. Disassembly and re-assembly is straightforward.
It operates of +12VDC and is not polarity sensitive, so simply applying voltage on the bench confirms operation.
If the system components are old and corroded enough to cause this to fail, now would be a good time to check all vacuum / emissions hoses & connections from the valve cover to the rear fender vent, and replace everything even slightly suspect because it will soon fail.
As we all know, any leak makes her unhappy!

 

For my own education, Stacey, did the P0445 come back after driving a while?