Hi,
My name is Reggie McNeil. I'm a retired Naval Officer with 40 years of service!
I purchased my 2006 Jaguar XJ8L brand new in August of that year. It was my wife's birthday present . I only have 38K miles and it is in mint condition both inside and out to include ALL scheduled maintenance. Other than a Bluetooth synching problem which apparently cannot be resolved I have no complaints. Several months ago without warning and no evidence of ANY operational, mechanical or engine malfunctions my engine check light just popped on. Dutiful as I am I took it into the dealer. It was reset and I was sent on my way. However within several weeks it came on again. They checked for error messages made whatever adjustments called for by "Tech Assistance" and off I go. Now the light comes on and won't go off even after being at the dealer 2-3 weeks at a time. My latest 2 week sabbatical resulted in them replacing the power module which they absorbed the cost! Brought it home yesterday no problem. Today I went to start it and no go! AFter reading the manual I discovered the infamous "Interim Switch" reset it and back to working order EXCEPT that darn light is back!https://www.jaguarforums.com/forum/i...on_special.gif Both my service writer and apparently the service technician are baffled not to mention my frustration. What are they missing??

 

You need to get a code scan
I would suggest you get your own Mongoose and SDD and do that yourself

Cheers
34by151

 

Get a new service team. The CEL should never just be "reset" and you sent on your way. It came on for a reason. That reason needs to be properly diagnosed, explained to you, and have the appropriate repair made. "Power module" is vague and means nothing. Now, if diagnostics showed it flagged a code for a small evaporative systems leak, chances are the fuel filler cap was left a little loose once, in which case tightening it and clearing the code would be the right fix, but that does not seem to be the case here.
The x350s are pretty solid cars, and as far as CELs go, they really don't come on that often. The most common thing we see are fuel trim issues, typically lean conditions on both banks. A cleaning of the fuel injectors usually fixes it (not just a can of solvent poured in the tank, an actual cleaning) and improves driveability all around.

Keep us posted on this one. I'm anxious to see how it turns out..

 

Welcome to the Forum.
Please take time to visit
New Member Area - Intro a MUST - Jaguar Forums - Jaguar Enthusiasts Forum
and introduce yourself so we can all say 'Hello'
You must get a code reader. The best VFM is, I believe, an app called Torque running on an android phone with a bluetooth OBD dongle (from Ebay) plugged into the diagnostic port.
It captures codes and 'live data' like fuel trims.

 

Hi Reggie

Late last year I had the CEL light staying on when I started the car. I am referring to the little pic of an engine in the instrument panel. After a few more start cycles it would go out, and stay out for a while, then come on again, then disappear; you get the idea. There were no other symptoms at all and the car drove completely normally. I should mention that I had had a recent gearbox service incl a new TCM connection seal, as these tend to start leaking after about 50k miles.

Anyways, the upshot was I took it back to the shop, who checked everything and said it might be the transmission selector assembly. The fault code indicated a miss-match between what the TCM was sending to the ECM, and the transmission assembly, and testing seemed to confirm this.
Anyways, a used but good selector mechanism was fitted, and all was declared well, but on collecting the car, the light appeared again, so they fitted a code logger. Damn me if I didn't run it around for a fortnight with no light coming on. Finally I left it at the shop for them to run around in for a week. When I collected the car they said they had disconnected every loom plug/socket in the relevant circuits and cleared the code. Nothing since !!

So after this long spiel, the question is, does the CEL stay on at start, or come on after start ?

 

Many thanks for your post. Probable the best explanation thus far. To answer the bottom line question...yes the CEL comes on at start and stays on. I am taking it back next Tuesday for an extended stay since I'll be on vacation. I will be sure to add your post and a few others one in particular that mention the fuel trim of filler cap. I also wondered if it is the fuel mixture itself that is being detected as insufficient in terms of the industry's approved additive?

Thanks again and I'll definitely keep an updated post to the problem.
RBMAC1 2006 Jaguar XJ8L

 

Hi again

In my case the fault code pointed to a gearbox status mismatch. It is to do with whether the transmission is in Park or Neutral which it has to be to permit engine start. The TCM sends a status, as does the tranny lever.

The technician detected an occasional bad switching signal when moving the tranny lever, hence the advice on replacing it, but a dirty connection clearly has the same effect. Fault has not returned since the job was done last year in Autumn.

 

Good Morning Fraser,
Your replies are very helpful and I just want to thank you By the way if you think it would be more helpful do you have access to a trouble shooting list that I could use when dropping off my car for the service technicians as well as their tech support?? If so, please send away

Once again many thanks for the speedy replies

RBMAC!
"Reggie"