About to replace my battery on '08 XJ8. Any before, during or after to-do's? I don't think this era JLR vehicle has anything besides maybe clock, radio presets and window prgramming that needs attention after.

Thanks for help

Randy

 

You'll clear all the learned OBD data such as fuel trims & monitors (used for smog in some places).

"Should" re-learn and re-set monitors without drama - if all is working well.

For battery a decent lead acid. No need for AGM, I believe.

 

I recently replaced mine with a "order on line' battery from WalMart. They do not stock them, worth the wait -if you can saves $$$$ money. Don't know who makes their but I have good luck with all of them that I have purchased in the past.

 

If you need to save OBDii and variouse memory in your car:

I use battery tender: connect tender to GND (body) and large power fuse. Then disconnect battery. This will keep car powerd while you change battery.

 

Tackled this job yesterday and 15 minute job turned into a pain. The thin circular clamp on the + terminal has a bolt that pinches it tight to post. At some point a weak point in this design caused band to snap. I was confused why I could not tighten down until I saw this. Apparantly it was staying on the post just by friction of previous tightening.

Car was blocking my garage so could not use other car to get to auto parts store so Uber'd to road where there are three of them. No JLR dealer in my town🫤

Finally best I found was a #2 gauge replacement even though XJ must be a #1 or #0 gauge since by eye it was a tad fatter.

Anyway, finally got this in and she started up fine. Couple side effects of new battery. My "Cruise not available" msg went away and...even though owners manual said I would need to enter radio code, I did not need to. Radio still worked and grateful since PO never wrote down code in the manual

So a pain but feel things might be a bit less flaky using fresh battery. Best I can tell the old one was 8+ yrs old 😲

 

Regarding radio codes: when I got mine I went to dealer brought in registration and just asked for code. I think there was a nominal charge, but i do not remember clearly, may be not.

 

US cars didn't have radio anti-theft codes, so your radio works fine after battery replacement. Tuner memory presets are gone, you'll have to redo your windows to reset the auto-up, and bump the clock up the 4 or 5 minutes it took you to swap the battery.

 

Where is large power fuse located?

thanks in advance

 

I use one 80A fuse in front fuse box:

One can use "mega fuses" as well, they are somewhere in vicinity of battery in the trunk.

 

I never had any issue by just disconnecting the batttery without any backup power. The car alsways drives fine, so no issues with OBDII codes.

The only thing gone are the data of the trip computer, including the partial mileages A/B that you can write down before disconnecting the battery, and you need doing the already mentioned re-setting of the radio, windows and clock. Even the seat memory setting remains stored while the battery is disconnected...

Best regards,

Thomas

 

@Thomas-S. True! Backing up power just saves me time not to deal what you just said. More important, when it is wife's car, when this helps me avoid frantic morning calls "The car is broke! Window is not coming up, Android auto does not work, How am I going to get to get to work on time? Clients are waiting!"
This is not just about Jag, but any car now days.

 

Just set up everything as soon as you reconnect the battery, and no more morning calls...

Jokes aside: I know what you mean, and the more modern the car is, the worse it gets... if I only think that in many cars nowadays you cannot just replace the battery anymore, you have to configure it to the car... That's one of the reasons why the SV8 is the most modern car I own (built in September 2003), and I do not plan to change this anytime soon. My everyday runabout is a 1998 Audi A4 Station Wagon, also perfect for winter as it is very well rustproofed, and the average age of my cars is >30 years...

Best regards,

Thomas