Hi all, I appreciate this seems to be a problematic issue on these cars (2006 xk 4.2) with a variety of different issues, but hoped someone may be able to give some pointers with my exact symptoms.

My screen remains off for the majority of the time, pressing the power or home button usually gets its to come alive but it’s only for a second or two before going blank again. Strangely though the actual touchscreen function of it still works absolutely fine. I.e I can touch it with the screen blank and it responds to my presses. Everything else works on it fine, for example the radio works great, and somehow even with the screen blank a little pop up box with the volume will come onto the screen when changing volume.

I’ve adjusted the setting to stop auto dimming brightness, removed the sat nav cd in the boot and also charged the battery (with a 5a 12v charger) to rule out other fixes that I’ve read on the forums, but would be grateful if anyone has any advice on what could be the cause of this specific issue please?

Many thanks.

 

About 80% of the time this occurs is because BATTERY. (Almost everything is because Battery)
Charge yours up, make sure it maintains 12.6V even after a few hours, or get a new one.
24% of the time it a Bad Screen.
There are a couple threads on here about replacement.
Try the first part first though.

 

thanks for the reply. The car has been connected to a smart charger for the last 24 hours, showing completely full. Even with it still connected and the car started the problem still persists unfortunately.

A search on eBay shows replacement screens are as much as £1000. Ouch! I’m sure there must be common faults on these that can be fixed rather than a replacement?

thanks again

 

Unfortunately becoming more and more common as these age. If not a voltage problem, then it's a failing display. Only fix is replacement with used one with unknown life expectancy or repair by a qualified electronics specialist.

 

Would be grateful for more info on this if you have any. There must be a firm offering fixes on these for far less than what replacement parts cost. Thanks

 

I’ve heard the Freelander II/ LR2 screen is a direct replacement…. but you are still dealing with used goods…

 

Did a bit of troubleshooting today. Battery after 2 days of charging on my ctek (on recondition mode), still the same.

Battery voyages are 12.5v when engine off but electrics on in the car (and all off too). 14.6v when car running. Checked the service history and battery is only a year old.

Unplugged everything one by one in the boot (nav unit and thing under it), had no effect.

Removed the touchscreen from centre console, checked all connnections, re plugged everything, still no difference.

Further testing shows that the screen comes to life for a few seconds each time the start button is pressed, whether to turn on the electrics, or to actually start the car. Then it goes off and stays off until the home or power button is pressed a few times, then goes off after the same few seconds. The unit does not reboot, it just comes straight back to the screen I was last one. Touchscreen function works the whole time, just not display to what to press.

I’ve looked elsewhere in the car for related electronics. I can’t get under either seat, but it doesn’t look like anything is under them. I’ve heard it’s worth checking the ground for the unit but despite studying the maps in the sticky, I can’t find out where mine is.

Grateful for any advice or whether to call it a day and bite the bullet on a replacement. Thanks

 

Hello @KILOCHARLIE ,
12.5v is not a fully charged battery. Your reading of the voltage whilst the car is running is that provided by the alternator, and not relevant. And I am afraid that you still cannot rule out the battery.
I concur, "unplugging" everything is a waste of time.
At the stickies at the top of this forum you will find a link to the electrical diagram, which includes the locations of grounding points.
You will also find the Workshop manual for your car.

But I must say, as I've done frequently, without the DTC codes, you are taking a path of the most effort. I had to take this path once as my system would not come on at all.
My process it to confirm power (+ve and -ve), then go from there. In my case it was a GND issue.

 

No, there’s nothing under the seats. The MOST system is either in the dash or in the boot stack on the right. I had a similar issue, my “fix” was Turing off auto brightness and decreasing brightness 1 click below median.

 

As @guy notes, your battery may still be the problem. Use a voltmeter not a plug in toy and check voltage at the battery. It should read 12.6, not 12.5 and that's not splitting hairs. FWIW:Interchangeable Model Numbers: 6W83-10E889-AC, 6W83-10E889-AD, 6W83-10E889-AE, 6W83-10E889-AH, 6W83-10E889-AJ, 8X23-10E889-AC

Will fit and work in:
2007 - 2011 Jaguar XF
2007 - 2009 Jaguar XJ
2007 - 2009 Jaguar XK
2007 - 2009 Jaguar XKR
plug and play. but you appear to have a battery issue and should eliminate it first. Any auto parts store will load test it free, they will then charge it for you ahead of purchase for no cost. The if you still have the problem, use the part numbers above.


And so we're clear our 2007 is your 2006 model year as they were built for the US a year later.

 

Thanks, that’s great info. My voltage was read with a voltmeter and I should have been more accurate in my last post it was 12.61v with engine off. With ignition on (engine still off) this dropped to 12.52v.

Should I be taking it with ignition on or off please?

I believe the issue was also apparent long prior to the new battery being fitted (and subsequently). The car belongs to my recently deceased father but I remember him mentioning the issue further back than when the battery was changed. Thanks again

 

With everything turned off so there’s no draw. That’s why batteries are usually bench tested out of the car.

Did you try my suggestion of adjusting screen brightness?

 

Thanks, yes I did try your suggestion to turn off auto brightness after coming across your original thread. I haven’t tried turning the brightness down though, I shall try that tomorrow and report back. Thanks again

 

A caveat to the way this thread has turned...
You may very likely have a dead or dying TSD unit.
The focus has been on the battery so far, as that is usually the problem. Most of this conversation has been about the proper and best way to rule the battery condition OUT of the equation. It has taken a good bit of posts to get to this point, and that is to ensure everyone in here knows the best and proper way to test a battery condition, because yes, the battery is usually the main culprit.
Test battery, at rest, at least two hours after any charging or draw, to include any engine-running or ignition on conditions.
Test the battery On The Posts with a good meter, not a Micronta from the 1972. It must be 12.6 Volts DC or higher. If it isn't, charge the pee out of it with a 10 amp or higher battery CHARGER, preferably with the car's negative battery cable disconnected.
An alternative with a little work, with better results, remove the battery and take it to either an Auto Parts Store or similar and have it Load Tested. An amp draw will be administered and the rebound capacity will be measured. A good shop or store will also charge it for you before another test, just to be sure.

 

Typically, following a confirmation of the battery health, I then confirm DTC codes.
If there are a number of codes (and it simply makes no sense) or odd behavior still presents itself, I then perform a system reset.
1. by removing the cables from the battery
2. touching the cables together to discharge any capacitance
3. reconnect the battery
4. follow your start procedure. reset windows, etc.
5. recheck DTCs.

 

It’s not uncommon for there to not be any DTCs even with failed components on these cars, whether electrical or mechanical.

 

Thanks for all the replies again.

I left car all day with battery unplugged. Checked voltage again, 12.62v. I’m confident this rules out the battery issue.

I tried lowering the screen brightness to see if that has an effect. Strangely while it doesn’t fix my issue, when adjusted below the median point setting, the screen goes completely off, no response from touchscreen, needs unplugging and re plugging to get it back partially working. No idea what this could relate to.

I’ve gone through all the electrical diagrams and found that there are 4 grounds for the associated system. The touchscreen one is “beneath centre console” does anyone know where that is exactly please and how to get to it. I can’t see any ground behind where the touchscreen is (completely removed) so I guess it’s beneath ashtray. Does that mean gear selector housing has to come out to access it?

if anyone has had ground issues, was this the one affected or the ones related to navigation etc in the boot. Thanks again

 

the grounding point on the outer panel of the passenger footwell was my issue.

 

The attached diagram may be helpful in locating the ground points (identified with a black dot and G prefix) in the car as well as connectors that may be associated with your touch screen. I think the G28 grounds are the 4 you are referring to and are on the right side of the center console.

 

@KILOCHARLIE , I’m afraid that’s not how DC voltage theory works.
I mean no disrespect, there are many who make this error.

For your interest, have a look at this: https://circuitdigest.com/tutorial/dc-circuit-theory

Thanks for asking the question. Whether ignition on or off, the voltage across the battery should be constant. HOWEVER, If under load you see discrepancies, typically this implies a “failing” battery. As others have stated, a proper load test is essential. For example, if a 900 A battery is only capable of 650 A, that is a depreciation (thus degregation) of -27 %. That’s not good.