Hello guys got a question first I checked out the hidden "TEST" mode on my 2008 X Type and I don't know how to read it or what the codes or letters mean. Can anyone please give a list or direct me to where to find out what it mean. I'm looking to see if my alternator is good and what the numbers should be. My car has been acting ip quite a bit I have to jump start it because the battery is a 650 CCA . Every time I turn it off have to jump it to start. Really need codes for battery and alternator. Tbanks

 

The stalk codes are VERY misleading most of the time. Buy an ELM27 and use the torque app on your phone. Read the codes and research them in this forum. If no codes the torque app still allows you to monitor real time functions of the car. R.p.m., fuel trims, battery voltage, etc.

 

With a 2008 car the codes may well be10+ years old. Ignore them and get an OBD tool.

 

You might like to check out this thread (post #5) which has a pretty through explanation and testing process for you to follow to check your alternator is outputting correctly with using a multimeter.
It gives you some voltages to be looking for depending on the instructions the alternator is receiving from the ECM.

https://www.jaguarforums.com/forum/x...-issue-244109/

I would have thought a 650CCA battery would still have the current capability to start the car, albeit the battery capacity is a bit on the light side as the 3.0 models up to 2006 were NPDIN77 (approx 640CCA) and post 2006 is NPDIN88 (770CCA) .
You might be suffering from some losses in the heavy cables between battery to alternator and alternator to starter. Quite a common thread conversation those cables, due to cable age and condition (internal corrosion) or bad connections.

 

PeterGunn, like was posted above, follow the directions of my Post #5 and see if we can eliminate a bunch of stuff. Granted, if you are able to run the car, turn it off, then come back a few hours later and not be able to start the car, then this is more than likely a ground somewhere that is causing something to remain running and it is killing your battery power. This is its own little monster to figure out. But, I do have a solution for that too. Gotta love little electronic tricks of the trade.