2006 XK8 with 120,700 miles....

Took the car out on a 20-mile joyride this past Friday morning to keep it routinely exercised. No issues, no warning lights, just normal performance....

Moved the car to a different part of the driveway this morning and noticed the amber "Check Engine" icon stayed illuminated on the dashboard. Pulled the code with my generic scanner: P0447. JTIS says "EVAP canister close valve circuit - open circuit".

Successfully cleared the code with my generic scanner. Started the engine again and the P0447 code immediately returned....

Is this usually an air leak? An electrical problem? Perhaps it could be something as simple as a loose gas cap even though it has been several weeks since I filled the gas tank. I will unscrew and tighten the gas cap just to be sure but I do not expect to be lucky enough for that simple action to magically fix my issue....

Suggestions?

 

Unfortunately, cleaning the gas cap seal and ensuring it was screwed down tightly made no difference. The P0447 code returned as soon as I started the engine again....

Additional guidance would be much appreciated....

 

Does this help?

xkr-code-p0455-83574

 

^^ Thanks for posting that old thread. It appears to apply to the 4.0 cars. I wonder how similar or different the 4.2 cars' (like ours) evaporative emissions components happen to be. Probably worth jacking the rear end up and having a look at that area to see if I can spot any evidence of vapor hose degradation. I have yet to smell any gas fumes as some owners tend to report. I would think that a valve or a solenoid could also be the issue but I lack those troubleshooting skills and tools. Perhaps someone can guide me through the process....

 

Forget the vapor hoses and EVAP canisters.

P0447 Possible Causes (the issue is ELECTRICAL)

EVAP canister close valve power supply circuit: open circuit, short circuit
EVAP canister close valve to ECM drive circuit: open circuit, high resistance, short circuit to B+ voltage
EVAP canister close valve failure

The CCV or the wiring is faulty?

 

Bob,

Thanks for your reply. Now we need to figure out whether it is the wiring or the CCV itself....

 

Hi Jon,

As always, Bob is our friend and mentor!

Here is a snip from the DTC Summaries:



Cheers,

Don

 

Thanks Don. I have spent some time this afternoon reading up on the evaporative emissions system on my JTIS CD. Tough to plow through to find the relevant information but I am trying....

 

I have been scrolling through my JTIS CD (in the 2004 XK8 section) during much of this afternoon. I have seen almost no reference to the infamous Canister Close Valve (CCV). Plenty of descriptions, drawings, and removal/installation instructions for the Canister Purge Valve (CPV) located in the left front wheel well, but no substantial information thus far about the CCV....

Is the CCV located underneath the car approximately midway between the two Evaporative Emission Canisters (which appear to be mounted below where the gas tank sits)? Is the CCV bolted to a bracket that hangs down from the chassis? Is anyone aware of any removal/installation instructions for the CCV?

Thanks for any additional information you can provide as I attempt to learn more about what must be accomplished in order to fix this frustrating issue with my wife's 2006 XK8. Once I gather enough information, I will put the car up on jack stands and attempt to get a good look at the CCV and any wiring running into it....

 

The appearance of your CCV will be similar regardless of whether your car has the Onboard Refueling Vapor Recovery (ORVR) or Running Loss system, but here are the parts diagrams, showing the valve near the canisters for either system (these diagrams are from jaguarlandroverclassicparts.com):

Twin Canister System - ORVR:


The ORVR part number is LJC1525AC and it looks like this (photo courtesy of SNG Barratt):





Twin Canister System - Running Loss:





The part for the Running Loss cars is LJB1525AB and looks like this (photo courtesy of SNG Barratt):


If Jaguar published any instructions for removing and replacing the CCV, they would probably be in the Workshop Manual.

Here's the schematic from the 2003 Electrical Guide (I don't have a newer one on this computer apparently):



The valve receives ignition-switched B+ power on the White wire with Purple tracer stripe, and is grounded by the ECM via the Orange wire. Your wire colors may differ, but it should be easy to determine which is the power wire, and to test both wires for shorts to ground or a short to each other. Also note the connectors the Orange wire passes through - all of those would be worth inspecting and cleaning. Chances are the White/Purple wire also passes through connectors - you'll have to follow it back to its source via the schematics.

Cheers,

Don

 

Don,

Thanks so much for your extremely helpful post. You provided far more detailed information than I was able to glean from several hours of searching through my JTIS CD yesterday. I know nothing about these evaporative emissions systems and I truly appreciate all the help I can get....

I presume that by crawling underneath the car and having a careful look, I should be able to determine whether my wife's 2006 model has the Onboard Refueling Vapor Recovery (ORVR) system or the Running Loss system. I presume that the ORVR system is the newer version and because her car was built during the last month of the XK8 factory run in May 2005, I expect to see the ORVR set-up....

Thanks again for your kind assistance. We could not successfully continue to own this car without the expert guidance from the very gracious members here on the forum....

 

Personally, I've never liked JTIS and have found it cumbersome and frustratingly incomplete, so I lean toward other references whenever possible.

Just a quick summary of the evaporative emissions system to help visualize what it does:

The objective of the system is to reduce the amount of fuel vapors released into the atmosphere. To accomplish this, vapors are drawn from the fuel tank into a canister filled with granules of activated charcoal, which absorb the hydrocarbons for storage. The air in the vapor is thus "purified" and the canister close valve opens periodically to vent the air into the atmosphere by way of a filter.

The charcoal granules can only absorb a limited volume of hydrocarbons, so under certain running conditions (engine & coolant at operating temps, closed-loop fueling, etc.), the purge valve (or EVAP valve) opens gradually to avoid momentary rough running from a sudden change in air-fuel mixture and manifold pressure. The vapors are drawn from the canister into the engine air intake ("Induction Elbow" in the diagram below) where they are burned in the combustion process.

By monitoring the upstream O2 sensors and the drop in manifold absolute pressure, the ECM adjusts the fuel injector pulses to accommodate the extra fuel being drawn into the engine during canister purge.

On some vehicles there is no CCV, and the 5.0L vehicles have a changeover valve as part of a Diagnostic Monitoring of Tank Leakage (DMTL) system, which is even more complex.

Here's a diagram of the S-Type/XJ system from an EMS training manual. The XK system is similar, though you will probably have two canisters:




There is a detailed explanation of the ORVR and evaporative emissions systems in this manual:

Jaguar Training Program: Engine Management Systems and Advanced EMS Diagnostics - Book B

Cheers,

Don

 

Thanks Don. A well-written synopsis of how the evaporative emissions concept works....

Yes, JTIS is indeed cumbersome to use and often lacking in both substance and detail. And it ends at the 2004 model year. But for a grand total of $6 on ebay way back in early 2009, it was the only Jaguar "service manual" I could find at the time....

 

Update:

Dale (crbass) and I got together at his house this afternoon to troubleshoot this pesky P0447 issue. We knew the symptoms thus far pointed to either the wiring related to the canister close valve or the canister close valve itself....

The wiring passed all of the prescribed tests detailed in JTIS, so we turned our attention to the valve. Dale decided the best approach would be to apply external power to the valve to see if the solenoid would operate. It did, so he exercised it multiple times and it responded properly. Dale then put everything back together, I started the engine, pulled out of the driveway, and after a hundred yards or so the amber Check Engine icon on the dash magically disappeared. The 25-mile drive back home was accomplished with no more warning icons appearing on the dash, so for now all is well again....

The good news is that now we know if the problem returns, I just need to install a new canister close valve (part no. LJC1525AC). That is indeed great to know....

Thanks again Dale! Your efforts today are much appreciated....



By the way folks, you should see Dale's new custom wood dash panels and steering wheel. As good as they look in his photos, they are spectacular in person....

 

Update:

Unfortunately the P0447 code returned this morning, as did the amber Check Engine icon on the dash. I will order a new canister close valve tomorrow, install it once it arrives, and then update this thread with the results....

 

BUMMER!!!!

 

No worries, Wayne - I would much rather have to install a new valve (easy access right there at the bottom of the passenger-side canister) than have to tear the car apart looking for a wiring issue !

 

Update:

The new canister close valve came in this morning so up in the air went the rear of the XK8 and underneath I crawled. Fighting the hose clamps in a cramped space was the biggest hassle but I finally managed to remove the old valve (just one 10mm nut holds it on its bracket). Based upon previous posts I expected it to look dirty/rusty inside but it was actually quite clean. So on with the new valve, reattach the hoses and electrical connector, lower the car, clear the old codes with my scanner, and off on a 10-mile test run. No Check Engine icon, no codes, and 4 monitors still need to complete so it appears more driving will be necessary, perhaps a specific pattern of driving requirements. I will put more miles on the car while my wife is out-of-state for the next week....

Thanks to all who assisted in this effort, especially Dale....

 

Update:

I started the XK8 this morning for the first time since bringing it back home from Wednesday morning's 10-mile test-drive immediately after installing the new canister close valve. The Check Engine icon stayed on and Code P0447 returned. While the engine was running, I successfully cleared the Code P0447 and the Check Engine icon disappeared. I let the engine run for a minute or so, then shut it off and removed the key. I waited perhaps 30 seconds, inserted the key, started the engine again, and sure enough the Check Engine icon and Code P0447 immediately returned, so I successfully cleared them again. I repeated this sequence three additional times, all with the same result....

So it appears that I can clear the Code P0447 and the Check Engine icon after each engine start-up and then drive for as long as I care to with no more codes or warning icons. But as soon as I shut the engine off and remove the key, the next time I insert the key and start the engine, the Check Engine icon stays on and the Code P0447 returns. What could cause the start-up sequence to continue to create these problems when the wiring tests checked out normally at Dale's house last Saturday and I installed a new canister close valve on Wednesday? Very strange indeed....

 

You can check the code book, but this is likely a true permanent problem the ECU detects right away, but is only required to report on the second start if it is still there (in the off chance it goes away). There is likely a pending code appearing right away if you can convince your OBD tool to read it. In other words, I believe you are describing "standard" OBD reporting of a stable/permanent problem. I am way, it is a better than a random sometimes problem.

From memory, this code has been discussed before, and the emphasis had to be refocused on the electrical nature of the error, not its net effect (like bringing fumes to be burned and detected by the O2 sensors). It might be time to revisit the wiring. Or double checking the connector is properly snapped, especially if the access is awkward. Might also want to try and disconnect the valve on purpose to see if the same code/behavior occurs.

Best of luck, keep us posted.