We parked my ‘05 S Type Jag 3.0 at a public trail and park near Golden (Colorado) last night. I did leave the parking light inadvertently on still not familiar with lights not automatically going out when you shut off the ignition. When we came back I could not drive the car because the breaks were locked. I did look online and found a formula which began with undoing the negative post on the battery. But it was cold and dark out and I just could not get the negative clamp off the post with the few tools I had. So this morning I looked online again and a video showed opening the panel just above the battery in the trunk and disengaging two multi wire plugs. I did this, left them disengaged for twenty minutes or so, plugged them back in and the yellow light and parking break fault notice were gone! Later I went back out to put the car in the garage and when I turned the car on once again I got the warning. I turned the motor off, waited a few minutes, turned the car on again, and it was fine.

What’s going on? There were some older discussions about this but involved, as I recall, cruise control and other things. I am simply getting the yellow warning light on the left side of the speedometer, and a notice of a parking brake fault.

 

How old is your battery?

 

Just bought the car in May and it looks new. But I am really not certain.

 

Break out your voltmeter. Check the battery voltage before start. It should be at 12.6v, which is a VERY high standard. In your first example, the battery had been partially run down due to the lights left on.

Some light reading:

https://www.jaguarforums.com/forum/s...attery-193787/


https://www.jaguarforums.com/forum/s...pe-faq-123983/


You are correct that DSC and cruise control faults typically accompany a parking brake fault when low prestart voltage is present. But the battery voltage is quick to check before doing anything else. Keep in mind the battery itself may be fine. The battery could be a little low due to a marginal charging system, or something causing a drain while parked.

 

So the battery was tested and the charge was low. So I bought a charger and charged the battery. So far everything is cool . And the car is doing things I don’t remember it doing, like the driver seat moves back when you get in the car, and up when you start it!

 

That is normal if you have the rotary switch on the left side of the steering column set to "auto/automatic". Not all cars are equipped with this, I believe.

A nice evening settled down with the owner's manual might eliminate some of the surprises you have been experiencing...

 

If you have them set to auto they should go out, you can also adjust the delay period before the switch off.

 

Good advice here. I am learning slowly. A friend said batteries typically have a date on them. My battery has markings for the installer to note the date but that was not done. Additionally no indication of a battery on the car fax. Think I will get a new battery.

 

Glad this has all worked out well for you. The 2003+ cars are VERY sensitive to the battery's overall health, not just state of charge.

Do you have another vehicle, perhaps something older? If the battery is the same size, some folks have saved a little money by putting a new battery in the Jaguar, and transferring the old battery to their other vehicle. That way the newest battery is in the Jaguar, where it is most critical. The used battery can continue to provide adequate service for a few more years in an older vehicle not prone to electrical glitches.

I have a friend that does this with his Lexus and old pickup, and I used to laugh at him, but now I understand why. I have an old pickup, too, but the battery is physically smaller. When the truck battery needs to be replaced, I'm going to see if I can modify the mount to accept the existing (mid-life) Jaguar battery, and put a new battery in my car.

 

Hmmmm...... Just sayin' n post #2

 

I have a credit of $117 at Costco. Is there a brand that the knowledgeable folks here prefer?

 

To be honest there are only 2-3 major manufacturers of automobile batteries; most are "label engineered" from common sources. The length of warranty is "usually" an indicator of build quality...