2 days ago I received a Fail Safe Engine Mode warning light, then the next day the Check Engine warning light came on. Cars performance no different. Cruise Control stopped working. Driver side window goes down with the open latch from both the inside and outside and does not return to the up position when door is closed. Any ideas as to what the issue is? Help please if you can. Thanks in advance.

 

These are all issues related to voltage drop. Have your battery checked and replaced if required. Then clear the codes and all should be good.

I was recently out of the country and when I returned my battery was dead. I had similar issues and once I recharged my battery I had to have the codes cleared. No problems since.

 

Also after the battery you may have to reprogram the window.

 

Thanks for the replies. Since I've had the car for nearly 7 years now and had not at any time replace the battery, I went ahead and bought a new one. Alas, the problems did not go away. Had the codes cleared as well but within driving it for no more than 1 mile, the problems returned. Any other ideas? Really do appreciate this forum. Thanks.

 

Had the same problem a year ago. Took it to the Jaguar dealership here in Massachusetts. The service manager said it was the brake switch before he even checked the codes. Sure enough, it was the brake switch. They replaced it, and cleared the codes. No more issue......

 

Hi, rh!

I had the exact same symptoms with my 99 XK8 and all were battery/voltage related. Mine were intermittent--the error codes would come and go--until I replaced the battery. The brake switch is a good bet, too.

If the brake switch tests OK, here are some suggestions:
1. If you replaced the OEM battery with an aftermarket battery, check the new battery's full performance specs and verify that the amp hour rating at rest and under load meets or exceeds the OEM Jaguar battery specs. Jag installs a big battery for a reason: a relatively small drop in battery performance causes numerous vexing problems and error messages.
2. If all is well there, try deep-charging the battery. a) First, lower the driver side window far enough to clear the rubber window seals completely (Important! You must do this to avoid damaging the window seal or the window if you need to open the door while the battery is disconnected). b) Remove the battery cables, negative cable first. c) If the new battery is not a closed-cell type (read the top of the battery), check each battery cell to make sure there is adequate fluid; if needed, add distilled water only. d) Attach a "smart" or trickle charger to the battery overnight to ensure that the new battery receives a full, deep charge. (A good rule of thumb is to divide the battery amp hour rating by the charger's amp output, giving you the total charge time in hours. Then add 10 percent extra time ensure a complete charge.)
3. While the battery is charging, check the car's battery cables for corrosion. Pay close attention to the ground cable connection to the vehicle and the positive connection to the junction box. Remove minor corrosion using contact cleaner or heavy corrosion using a baking soda/water mixture and a wire brush (wear safety glasses, please). Replace the cables if the insulation or cables themselves show aging/wear/corrosion damage.
3. After the battery is fully charged, remove the charger and reconnect the battery cables, positive cable first. Optional: after reconnecting, give the cable clamps and battery terminals a light coating of petroleum jelly to better protect against corrosion.
4. Start the car and reprogram the windows: with the door closed, lower the window completely and continue pressing the down switch for at least 5 seconds. Immediately raise the window and continue pressing the up switch for at least 5 seconds.
5. You'll also have to reprogram your garage door opener buttons and perhaps re-enter your radio code as well.
6. If you still have problems, have your battery load-tested and get it replaced if it doesn't meet specs. Even new batteries can be defective. At the same time, have your charging system tested to make sure it's working properly. Whoever sold you the new battery should be able to do these tests.

If the battery and charging system are OK and you continue to have problems, you'll probably want to check for any electrical shorts that may be causing a slow drain on your battery. Search the forum, as there was a recent thread that discussed how to do this by removing certain fuses and using a hand-held voltmeter.

Good luck and please post your outcome.

 

I would go with the battery and then reprogram your windows. To do this you push the window down button and hold until you hear or feel a click. Then push the window button for the window to close and hear or feel the click. This should be done when you are in the car and the door is closed. The window should operate properly by opening a slight bit when the door is opened and close when the door is closed.
This problem is often caused by a weak battery voltage. 10.5 or below they loose memory settings.

Once the battery is replaced you need to reprogram the windows and check the other things that were not working properly such as you cruise control. This is often caused by a failing brake switch but could be a result of a failing battery. By the way it is not a bad idea to check all you connections but that is up to you. Hope this helps!

 

On my 99 XK8 I had an engine light on for some time but everything was working fine. I disconnected the battery which seams to be OK but never checked. The problem went away and has not returned.

 

You never know you may have corrected a problem (loose connection) when you pulled the lead off and reinstalled. Anything goes with these cars!