Without any previous indication of failure, 1 day, after parking the car, it refused to start. I jump-started it, and it started up just fine. I drove it for 3 minutes, at which point it started losing power until stopping completely. The fault indicator on the dash said transmission fault and the code reader I have says p 1638.
I jumped the car again and it started just fine but would not shift out of park at this point. I cleared the code but it came back. And once again said, transmission fault on the dash before dying.
Should I start by taking off the instrument cluster and inspecting the back of it? thanks in advance.

 

I forgot to post that it's a 2005 x type awd

 

Alit, the code P1638 says that you have a problem with the communication circuit between your instrument cluster and the ECM. If I had to take a guess, I would be looking near the center of the dash at the cable bundles that run there and near the point where the heater hose enters, you are going to find your problem.

 

Thermo, thank you very much for taking the time to provide a suggestion. I started my troubleshooting with using a buddy's brand new battery and it solved the problem. I then took it to AutoZone to test the alternator and it turns out it's bad, so that's why the car would die even after jump starting it. I did not know that a dead battery would make the car spit out random codes and faults (transmission) will keep an eye on it and see if the code comes back.
Thank you,
Aleks.

 

welcome to jaguar ownership!😂
they really really really like an up to date battery and they spit and hiss at 4 year old batteries... or younger.
if you get weird codes in 3+ years.... buy a battery 😉

 

. . . or better still, unless your pussycat is an every day driver, get a smart charger (aka battery tender like C-Tek etc). "Smart" is the operative word. the charger must not only power down when full, but also auto-start recharge as battery depletes.

Maintained with little use, my 2007 S-Type OEM battery (stamped '06) lasted a decade and its replacement is still giving faultless service. That's coming up to 20 years from 2 Varta batteries. Message is clear. These vehicles' electrics and electronics thrive on constant use or battery being regularly 'topped up', otherwise you can expect trouble. See the S-Type Sticky FAQs for a full run-down with pics.

Cheers,

 

IT sounds like you nailed it pretty quickly with the battery. If the problem comes back, or the batt/alt light illuminates, get a laser temp and check the temperature of your battery cables where they attach to the battery. If one is much hotter than the other, you also have a battery cable issue.

Best of luck

 

I have to agree here with a smart charger. I use battery tender brand, as that is what is most popular stateside, and have had nothing but good luck.