My wife called me frantically today. She tells me that the traction control button lit up yellow then red. The screen where the time is displayed turned to a Red triangle and the message "Engine system Fault" is displayed. The vehicle is a 2009 XK 4.2 NA. I told her to pull over and wait a few minutes, restart the car and see if the message/warning sign is still there. Turns out it's all normal now. I'm brainstorming as to what the problem might be, running hot, traction control failure, low battery, etc. Has anyone run into this? I know its a long shot but any help is greatly appreciated

 

Use a voltmeter to check the battery voltage across the terminals, which should be a minimum of 12.6 volts. If the reading is less than that, charge the battery for 8 to 10 hours at 3 to 5 amps, then retest. If the voltage is still less than 12.6 volts, the battery must be replaced.

Many of the electrical 'gremlins' and 'ghosts of Lucas past' are the result of a failing or weak battery.

 

thank you. will check that first

 

Get yourself an OBD code reader & read the codes.

 

There are no codes.. I have a code reader. The problem arose while my wife was driving. Im trying to troubleshoot so that it doesn't happen again to her.

 

Does your reader do all the modules? Most do just one - and some do not report that one fully!

 

I have access to a snap on scanner.

 

Our cars are definitely very finicky when it comes to battery voltage. I had all kinds of codes popping up when I had an old battery. It doesn't help that even with a good battery our cars seem to have a high battery drain. I also remember I read somewhere that part of the problem is grounding points on Jaguars that sometimes need to be reworked and they fix a lot of the electrical issues.

 

Yep. I didn't believe it until I witnessed it. And my old battery had good numbers when charged and idle.

 

Well, I drove it today. The problem came back. There was a significant power drovp. the car feels choked. These are the messages I’m getting.

 

You didn't plug (or unplug) something into the OBD port while driving did you?
I did that once (trying to track a different problem), and got a bunch of crap like that displayed, and the car went into 'limp' mode. Thought I'd broke the damn thing.
Shut the car off, restarted, and all was back to normal (except for my original problem of course).

 

I

No, I haven't even scanned it yet

 

What is the voltage across the battery terminals with the ignition in the OFF position?

 

12.51

 

My recommendation is to take it to a jaguar specialist or dealership of your choice and get it fixed. No guessing or changing parts unnecessarily and no false economies. It will be returned to you functioning and usable. Now it is just a big useless paperweight. Without the proper diagnostic equipment you could be chasing your tail and stressing out for no good reason.

 

follow post 2

 

Which battery should I get? factory or gel type?

 

Which CTEK tender do you guys recommend?

 

Back about 2 months ago, I found this stray power cord zip tied to an exhaust hanger

now that I have the battery exposed, I’m thinking it might be some sort of charger! What do you guys think?



the cord leads directly to the battery terminals. I just can’t seem if it’s a CTEK or some cheap maintainer.

 

Looks like a ghetto DIY quick-disconnect. Using a 120V plug is asking for trouble as someone could easily assume it is supposed to be connected to line voltage, thence blow **** up.
I have a quick-disconnect on mine also, but I used the proper 12VDC connectors.