Hi All - new member and first post. Just bought my first Jag 2 weeks ago 09 XF Supercharged in Indigo with spice interior. Thus far I'm thrilled overall! Bought from a non-jag dealer with 35k miles, still with original warranty. Had the service engine light pop on yesterday and took the car to an official jag dealer this evening - was told that the vehicle is running "lean", an issue usually indicative of an O2 sensor like issue. I was told that the XF does not have such a thing, as a result the issue was that I've had the car in dynamic mode too often and not "pushing it hard enough" while doing so. So the resolve was a reset of the alert and too either punch it constantly while driving in dynamic or leave it swtiched off.

I accepted the diagnosis but thought it was worth a mention here - seems I've read a few posts indicating others use dynamic mode very often and have yet to see this issue mentioned. Any input is appreciated

 

No O2 sensor eh? Magic emission controls then. I know of no modern gasoline powered engine fitted to a road car without an O2 sensor, I think even racing engines use them.

Be aware there was a known bug in the '09 engine software that caused the CEL (MIL?) to illuminate and report a non-existent fault. The code showed a fault in the air injection (too much air, which would also look like a lean condition) which did not actually exist. After a number of starts the light would go out by itself, which is what a false CEL will do under some conditions.

I thought the bug only existed on some naturally aspirated 4.2 engines but maybe yours has it also. My fault code was P4011. Another posted fault code P0492.

It took Jaguar almost 2 years to track down this fault and get the software upgrade approved by the Feds. Make sure your car was updated. If this is the fault then it will show up continually. Every time the dealer re-sets the ECU to remove fault codes the engine will eventually throw the false fault code again. On my car the light would go out after about 3 weeks and then illuminate again a few weeks later.

How you drive makes no difference. Your dealer is blowing smoke on that one!

 

Thank you jagular - i was hoping you'd find the post and have some insight. When I first took the vehicle to them 2 weeks ago they mentioned 2 recalls - a software update and a gear shifter part (issue with stuck gear selection, I've seen that mentioned in other posts). They've ordered the shifter part, must not have applied the software upgrade to handle both at the same time I guess. I'll be sure to mention it when I stop back in. Awesome help

 

My fault code was P4011. Since the update I have had zero issues with the CEL.