To do a hard reset disconnect the battery earth lead and hold the lead on the battery positive post for ten seconds.
When you reconnect the earth lead do so cleanly, don't dither.
Remember - if you need and don't have a radio security code you're in trouble.
What this does do
Resets ECM defaults including fuel trims
Resets many other electronic modules
What it doesn't do
Erase any programming (re-flashes etc)
Erase the transmission module adaptive learning.

After re-connect (applies to 4.2L engines)
Re-enter radio security codes if required.
With thanks to Graham, Derek and Red1bw
1. window limit reset
2. audio preset reset
3. clock reset
4. Idle reset
5. Kickdown limits
6. Drive cylce
7. Powerfold mirrors

1 to 4 and 6 are covered in https://www.jaguarforums.com/forum/a...connection-pdf

After battery reconnection, the engine management system must ‘re-learn’ the limits of throttle pedal travel.

5, setting WOT,covered in JTP939
Re-programming is done with the ignition switch in position II a follows:
Slowly press the accelerator pedal fully through the kickdown detent to the floor. Hold 5 seconds
Release the pedal and repeat the action.
7. Powerfold mirror reset (thanks to Plums- from JTIS)
Loss of power supplies will result in loss of mirror fold-back memory. In the event of such a memory loss with mirrors in the normal position, fold-back will operate on second movement of the toggle switch. On loss of memory with mirrors in the fold-back position, they will return to the normal position on next fold-back operation.

 

Looks comprehensive. Off the top of my head, when I do a battery reconnect, even if disconnected for half a day, the clock (I do have navigation system clock and not the analog one), the radio, and the temperature settings (I think) are all retained. Not sure if this varies with the model year, doing a hard reset or not, or the amount of time the battery is disconnected. I have always appreciated not having to reprogram the radio and clock. Temperature is more simple, so I'm not sure about that one as I routinely adjust, so I would be less apt to notice that one.

Not sure, but does doing a hard reset make the transmission module go through it's learning again? And does a hard reset require more to be done than just a battery reconnect, or is it just a better way of "clearing" potential issues out? Thanks.

 

It looks as if specification does make a difference.

Red1bw (Bill) has SatNav but no Coded Radio. Mine is the opposite. I have a Coded Radio but no SatNav.

I've just checked mine with an actual disconnect.

1. Window Limits - lost
2. Radio Code - lost
3. Audio PreSets - lost
4. Clock - stays at disconnect time
5. AC - was on max Cold setting. Started up at 70'F after reconnect

Didn't do a hard reset - only a disconnect for 10 mins followed by reconnect.

Over to you Bill for the other half of the test.

Graham

 

One of the joys of owning a 4.0L I only had to do the windows, audio, and clock. The idle was high on first start and next startup it was back to normal. I haven't had the battery out since I bought a battery tender for this winter, and it was mild enough I barely used it, but this should be a good reference for everyone. Certainly FAQ worthy.

 

I've got satnav and don't lose the time as per Bill.

 

Things are indeed different for models/years.

Mine is mainly the same as GGG above but retains the audio and A/C settings.

 

I'm convinced the only thing that needs to be done are the windows. I followed GGG's format with other numbering addressing Steve-format afterwards.
I did a hard reset (10 seconds of - terminal on battery + terminal) followed with a couple minutes disconnected before reconnection. I have a 2004 US XKR coupe.

1. Windows: needed reset.
2. Radio code: not applicable.
3. Any / all audio and radio presets: retained (radio did come back in power off position even though it was on prior).
4. Clock (on navigation screen): retained.
5. Climate control: retained. (I set it on 61 - something outside the normal 70 I keep it around and it came back on at 61).

Steve 4: Idle reset- took care of itself automatically at first opportunity it had to idle for some time. In my case it was 5 minutes after driving it to a redbox to return a movie....kept car running when I got out of it to return the movie and when I was done, care was idling at around 600 (as opposed to 1000-1200 range). Of course, you can always force an idle and make it do it right away, but it will adjust itself anyways at first stop light or other idle opportunity.

Steve 5: Kickdown limits seemed to take care of itself between the 2nd and 5th flooring. The first time I floored it, it didn't feel right. The 2nd - 4th time flooring I was conservative due to it starting to rain, by the 5th - 10th time it was back to normal (I was outside of the rain area and drove it hard sometimes slowly pushing through kickdown, and sometime flooring it immediately from a stoplight). It clearly adjusted travel limits on its own.

Steve 6: While I didn't hook up my scanner this time, I personally take it as fact that a battery disconnection will put the car at the beginning of P1000 (regardless if prior it was 1-99% done a P1000, or a P1111) from past experience.

Conclusion: The Steve 4-6 issues seem to take care of themselves automatically, but there are clearly things you can do to speed them up. Especially by coasting on the Steve 6 item - this I believe helps turn my P1000 to a P1111 code in as short as 2 days instead of 3 weeks. Steve 4 and Steve 5 items will self adjust when idling and pushing through kickdown upon first opportunities. And regular items 2-5 you are just dealt based on model year, parts, options, and export market.

 

Bill,
I think you're right about 4-6, they do eventually sort themselves out but I find it takes a bit for the idle to become acceptable. I don't know if the mixture will sort itself properly without the prescribed training cycle.
It is worth doing the cycle just to get rid of the creeping at tickover.
I'm pretty sure from totally non-scientific observation that the ECU recalibrates the throttle to 100% on kickdown during driving - unfortunately I don't have a reader which gives % throttle or I'd try altering the throttle cable length to see if it recalibrates to 100%.
I think from other's comments that the various radio and climate control defaults are model and country dependent.

 

If those items didn't take care of themselves, I suppose that the Jaguar service department would be much more busy during the warranty period dealing with various complaints. Also, I don't even think Steve 4-6 are mentioned in the owners manual; and Steve 5, I believe is only mentioned in the PDI. These "adjustment" items seem to go against the concept of a luxury cruiser that automatically adjusts the suspension, with memory seats / mirror / steering wheel, auto headlamps, auto exit steering wheel, auto wipers, auto rear view mirror dimmer, auto antenna, and virtually auto everything - but wait, if you disconnect the battery you have to manually adjust or reprogram 100 things. Also, if these items weren't too automatic, I don't think these cars would have their 5.2 second 0-60 mph so consistently duplicated, especially in the early days before people like us had this forum, JTIS, JPEC, home WDS's, and the general knowledge that we do about these cars.
No doubt that doing prescribed cycles can't hurt. However, I doubt, that all these items would be done by a Jaguar dealer after a battery disconnect as no such list really exists to do all these items after one.
Anyone have any ideas on why the windows need to be adjusted (why doesn't it just store that information in a capacitor like everything else)?

 

Bill, don't forget 'proper' Jaguar owners wouldn't even know where the battery was, what it did or how to disconnect it.
They would have their 'man' take the car to the frightful dealer-person to have it mended.
Certainly these adjustments ARE covered in JTP 939 which does state the engine/transmission will re-learn the adaptive settings after a period of driving.
However I find the high idle after reconnect to be irritating and quickly fixed by the idle reset covered above.