I confess I didn't know how to word the subject line. My wife's 07 S Type 3.0 started giving a continuous warning tone when at a stop. The frequency is similar to leaving your key in the ignition, but is a sustained note. It only happens when the car comes to a stop, or very nearly stopped (if you reduce your speed gradually). The sound continues until the car reaches about 10 mph, then ceases. Sometimes it doesn't chime, but that mostly seems to be right after the engine is started, until the car once again slows to a halt. The owner's manual doesn't list any such sound. Also, we get no warning lights, and there is no error code set (at least none that my basic OBD II reader can report). We've tried jiggling the ignition key, or shifting into Neutral/Park but the sound continues.

We recently had the ignition coils replaced, and shortly after, started getting P0171 & P0174 codes (I periodically clear them to see how long it will be before they show up again - usually within 50 miles). I suspect that there may be an air leak in the intake manifold connection, but spraying carb cleaner around that area & around the more accessible vacuum hoses revealed no change. As an electronic systems troubleshooter of long standing, I know never to rule out anything, but I am reluctant to suspect both O2 sensors have suddenly crapped out. I mention all of this in case it could have some relevance to the chime problem. BTW, the chime only started 2 days ago, although the lean codes have been popping up for several weeks. The car is going back to the shop where the coils were replaced, but they are not Jag specialists, so I don't know if they can diagnose the chime issue.

Any thoughts or ideas? Has anyone ever seen (heard) this issue before?

Regards,
Joe

 

See if you can describe the chime better or even record it.

You really need to fix the cause of the codes. It may or may not be an actual air leak - see the jag doc about the codes to see the other possible causes - but carry out the fuel trim readings so often posted:

hot engine, parked, then LTFTs, then rev to 2500 or so and again LTFTs

Likely some damage is occurring so don't ignore the faults.

 

Sounds like it could be a PARKING AID sensor or system fault??

bob

 

Can you duplicate the noise while parked in your driveway? Just to be clear, I mean for the car to make the noise, not you.

Could the noise be caused by the vacuum leak? Vacuum is strongest at idle, so it may fit the pattern. To test, with the noise active and shifter in P, rev up the engine a little and see what happens.

Some one else mentioned the rear parking aid. Try switching that off and see if there is any change.

 

Busy weekend. Heading out now to replicate the problem; it never happens in the driveway (natch..). Definitely not a vacuum noise, btw.

I'll post again after I can measure values & record the sound.

 

Oh, yeah - how do you switch off the parking (backup) sensor?

 

The on/off switch in the overhead console applies to those cars with front and rear parking sensors installed. There is on switch for the rear sensor only equipped cars.

 

Stupid me; I thought that logging the data would show LTFT values, etc. It didn't (looks like GPS coordinates only - or whatever Gx, Gy, Gz, etc are)!

Now I have to go back & try to record those values manually.

The Perversity of All Things Mechanical also deemed that the warning chime did not sound at all during our 30 minute drive. It must be fixed, right? Anyway, it seems to be the same frequency as key-in-ignition or headlights-on (on a musical scale, it's C#6 - ~1110 Hz). Unlike the warning chimes, though, the one I'm asking about was a steady tone. And it is of a noticeably higher frequency than the back-up warning.

I'll make another attempt this afternoon.

Thanks so far for the input from everyone!

 

Well, I finally got the LTFT readings. With the engine fully warmed up & idling Bank #1 was -0.16%, #2 was -0.08%. At 2500 RPM, #1 was +7.8% & #2 was +10.2%.
I'm not really sure how to interpret this. It seems as though the increase in trim should run the mix more rich, not less.

Still no sign of the mystery chime tone, even after another 30 minute cruise on the scenic highway.

Also, the P0171/74 codes have not returned - not yet, anyway.

Joe

 

Joe,

Here's a good primer on interpreting fuel trims:

JagRepair.com - Jaguar Repair Information Resource

 

This link was a great aid to understanding the BIG picture of OBD II diagnostics and fuel trim information - thanks!

As I mentioned, the car went back to the shop today. Their tech saw essentially what I saw, but he knew what to make of it. After cleaning the MAF sensor the LTFT readings dropped to just a couple percent. I'm going to keep an eye on it for now & see if this stabilizes the situation.

Still no return of the mystery chime issue, so that is getting moved to the far back burner - hopefully permanently.

This forum has been an invaluable aid to my goal of keeping Angie's Jag in good running order. Thanks to everyone who contributes their knowledge.

Cheers,
Joe