Main battery replacement

[v8ajl]

Hi,
Just had new main battery replaced and car electronics re-programmed.Now have to use excessive pressure on footbrake
to allow starting.Is this re-programmable ? as before only light pressure required
Many thanks
Andrew Lee

[JimMann]

Hi Andrew, best to give us more of a clue by telling us the year and model of your car. Not aware of any link between electronic reprogramming and brake pressure for starting. Also, depending on your car / model year, there are different aspects that need to be reset after a battery change, so what do you mean by electronics reprogramming?

Jim

[v8ajl]

Good afternoon Jim
Thankyou foryour reply to my e mail.My car is a 2009 xk150 60 4.2litre. The original battery failed - charged to 13.2v on a ctek 5 but
dropped to 8.8v on trying to start .My local Jag independent dealer fitted a replacement and I was told there would be a cost involved
over and above due to re-programming .This involved not only hand brake reset and window functions but "telling the car it had a new power source".With the original battery set up the car would start with light brake pedal pressure but now my light pressure causes the "put foot on brake pedal to start vehicle" on dash.I have to push hard - emergency stop sort of pressure now to get the starter to engage.So my question is -has the re programming altered the necessary pressure on the brake pedal and can it be reversed or has something else changed? Hope that is not too long winded a reply.
Many thanks in anticipation
Andrew Lee

[Astromorg]

The only tie-up that I can see between the brake system and starting requirements is for the brake switch to be operated. It's a mechanically operated switch, so brake hydraulics don't come into it. Problem could be a faulty switch or the switch has become displaced and now requires excessive brake pedal travel to reach it.
Two checks I would suggest. First, while in Park and the Smart Key present, forget the brake pedal and operate the Start button. If all is well the ignition switched systems should all come on without the engine trying to start.
Second, while the ignition circuits are on as above, press the brake pedal down slowly and see at what point the rear brake lights come on (If they do!) They should come on almost immediately the pedal moves, but if not until the pedal is floored with some force, then that would again suggest to me that the switch has moved from its correct position or is faulty.
Finally, press Start/Stop button again to turn Off.
With luck, that will provide some answers and maybe a way ahead

[v8ajl]

Hi Astromorg,
Thankyou for your thoughts and suggestions re my starting problems.I did as you suggested and yes the brake lights came on with
very little movement of the brake pedal.The movement of the brake pedal has "returned to normal" whilst carrying out your
suggestion and the car started with soft pressure with the right foot.Cannot understand what/how and why but smiling again.Great to
able to access the font of knowledge out there.Thanks to you and Jim
Andrew Lee