So, battery is by far #1 suspect but if it's 100% ok then it may be a bad power/ground(aka earth).

Various of those faults are there because other ones are. Even so, they scream bad battery/power/etc.

 

I changed the battery in the key fob, and it is too soon to tell, but it is behaving differently. Fingers crossed. Things I've done already; got a battery maintainer & made sure the battery is fully charged, (no improvement), ran a 12 ga copper ground wire from the battery to the common grounds behind the headlights (no real noticeable difference).

 

I replaced the battery with a new one and even took it to O'Reilly's to have it checked out. No issues with it so I put it back in the car.
. The car starts just fine, but all of the faults show up about 10-15 seconds. The shifter is stuck in park so I can't even move the car because it was backed into the garage.
Any idea where to start?

 

I've never had my shifter lock in park for more than a few minutes. My main concern is passing inspection. My car seems to run at least as well with the check engine lite on from this. I wonder if this is something a tuner could deactivate. Like if it never checked communication with some sensor, it would never be disappointed, and throw a hissy fit.

 

I have no idea. I just took the battery out of my 2001 XJ8 and put it in the 2008. Unfortunately, the same faults are occuring.
. I suspect that if the shifter would come out of park then the other issues might clear up, but I am just guessing at this point.

 

There is always the method described in the video, with prying off the trim and releasing it with a screwdriver.

 

Have you done the tests often-posted about shifter issues? (Brake switch, shift cable bolts etc)

 

No I haven't done anything with the shifter yet because it has the standard audio and had no issues until sitting in the garage for over a month. It just seems like a power issue that is associated with everything else.
. I think that I am going to be forced to take the shifter console apart to try to manually release the shifter. I dismantled it once but I didn't find the manual release. Apparently I didn't remove enough things.

 

A flashlight is helpful, it isn't all that buried, but it is small and hard to see. You just trip it, and pull the shifter back, then start it in neutral, once it starts things should start going back to normal. I just got back form running errands with it, and it is still reacting to the new battery in the key fob. I know this sounds like voodoo, but as soon as I started it after the fab battery change it began searching like it was learning. First the engine started searching for idle, then the trans got loose, and started what I assume is adaptive learning, then the steering got heavy for about 5 minutes. All that repeated on today's ride, only for less time, and then the CEL went out. I need to go out this afternoon, we will see how that goes. BTW the battery in the fob appeared healthy, the functions of the alarm, locks etc., were flawless.

 

Sorry to hear about your troubles. I hate leaving my cars sitting, but sometimes there is no alternative.
Anyway, it seems like you might have a voltage issue, at least that is what I hope. If you have not already and if you have a some kind of meter, check the voltage of the car with the engine running. It should be above 13 volts if the alternator is working properly. If it is 12.6 volts or less, you have a charging problem. Good luck and I hope you find the source of the issue!

 

Wow, after trying everything else I suppose I can change the key FOB. I am willing to try anything now to get it fixed.
. I am also going to check out the voltage output from the alternator next.

 

Ok, I had the new battery charged, I replaced the key FOB battery, and I am still having the same faults.
. I spoke with someone else today who said that a simple tire pressure sensor could be causing all of the other issues. Is that possible? I still feel like there has to be something that they all have in common. Some single source has to be causing all of the following faults: ABS, Brake, Engine Service, Tire pressure system fault, cruise control, air suspension, low brake fluid, dsc not available, transmission fault,, limiter not available, cats system fault

 

No,
TPS cannot cause these issues. Release the shifter and drive the car a few miles. Clean the codes. All will be good.

 

Very old thread, but did you ever figure out and *** what happened. My car is doing the exact same thing and I can't figure it out

 

Generally is is low voltage that causes the cornucopia of faults. Charge the battery and try it again. they also tend to lock in park, so be on the lookout for that. I finally disabled my park lockout.

 

Did that battery is good and is charging correctly when running. Tried disconnecting the battery for 20 mins, nothing all the same codes are still on

 

Did you clear the codes?
Unhooking the battery does not clear them
Eric-in-Texas wrote;
I finally disabled my park lockout.
How does one accomplish this?

 

Going to take it to my work and hook up a scanner and see if it'll tell me anything.

 

Going to take it to my work and hook up a scanner and see if it'll tell me anything.