Had a bit of a oddity happen this evening. Was driving home and the CATS Fault light popped up on the dash as we were coming home. Get home and check the fault codes and the dash goes crazy and everything lights up. Manage to clear the codes and take the car back out and the car is fine for a little bit, but while I’m out I notice the battery voltage is lower than normal when driving. Get home and check the voltage on the battery and it’s barely above 12. When driving the battery voltage was 13.5 or so.

Would diagnose more but I’m leaving for a work trip for a few days so I won’t be able to check it more till I get back on Friday. Hoping it’s just a bad battery and not a faulty alternator, but if it’s the alternator I know a good garage that can change it.

If anyone has had similar experiences let me know.


2006 Jaguar S Type R 4.2 S/C V8

 

Low battery voltage will give you random fault codes.
Perhaps a new battery would be a good idea?
Mellow

 

S-types like 12.6 volts and will start throwing spurious codes at 12.1 volts or less at start-up. Like Mellow said, start with the battery.

 

Got a number for us? How much lower than normal?

 

It’s the battery voltage is 13.5 when you’re driving that means your alternator is working. But if your batteries only 12 after driving it’s not taking a charge so yeah probably a bad battery