Pretty sure this is a problem not only with L494 but across the JLR range. (Can’t find definitive answer)
I appear to be having an intermittent problem where the brake pedal goes hard when you initially try starting the car. You then press the start button, but the car doesn’t start but goes back into standby mode. This takes a few tries of pressing the brake pedal hard before the car will start

Some have mentioned potential brake booster, or brake switch problem?

Anyone had similar problems?

My take on it is, if the pedal goes hard then the stored vaccum is leaking/bleeding out.
To start the engine the foot brake needs to travel sufficiently enough to release the brake pedal switch, if the brake pedal is hard (i.e. no vaccum) you may not be able to move the pedal enough to release the switch, hence, no start.

Sounds like a vacuum leak or at least lack of vacuum to assist the brake booster.

Thanks for the replies, will have a good look at the system and see if anything stands out. Guessing that if it is a potential seal issue you would need to change the whole unit.

Unless a partial rebuild is possible?
Will be interesting so see if anybody else has had the same issue.

is the problem there all the time or when the car is not used for time i.e. overnight?

It doesn’t happen all the time, and the brakes seem unaffected.
Normally straight away before trying to start the car you notice the pedal is a lot firmer than normal.

I guess you could say it happens more in the mornings, as the other half never seems to have the same problem when leaving work later in the day.

I had this problem with my car. On two occaisions it failed to start entirely and had to be recovered to the dealer. First time it was with them for three weeks as they couldn't solve the problem but then seemed suddenly to start so i got it back. Second time after a few days with them I was told there was a faulty/corroded wiring connection underneath the car which they had fixed. So back on the road again although the problem of not starting first time soon reappeared. This coincided with finding out that there was no news on when I'd get my new car after waiting for a year. I cancelled the new car and got them to buy back my car as I'd completely lost faith in it. Tim
RRS sold and replaced with a Skoda Kodiaq after appalling RR Dealer experience and LR inability to supply new cars in any sort of reasonable time frame..

Did you have the hard brake pedal symptom as well?

Yes, I did. Garage couldn't convince they knew what the problem was so all confidence disappeared as did the car shortly after. Tim
RRS sold and replaced with a Skoda Kodiaq after appalling RR Dealer experience and LR inability to supply new cars in any sort of reasonable time frame..

I wonder if you bought my old car? Is it a dark blue P400with ivory interior? Tim
RRS sold and replaced with a Skoda Kodiaq after appalling RR Dealer experience and LR inability to supply new cars in any sort of reasonable time frame..

No mine is a 2016 Yulong white Autobiography.
Have just tried starting car again this morning and again same problem. Took multiple times before car would start. Pedal initially wasn’t rock solid so thought it would start first time. Seems that the ignition lights on the dash go off quite quickly when trying to start car in this way.

If brake booster is faulty and is dropping vacuum through the night, would this stop the car being able to start I.e a sensor detecting vacuum levels?

Sorry but I really don't know if that might be the cause. As said the dealer was unable to explain what was wrong with the car to me after prolonged and I guess expensive investigation. Fortunately the work was covered under warranty. Tim
RRS sold and replaced with a Skoda Kodiaq after appalling RR Dealer experience and LR inability to supply new cars in any sort of reasonable time frame..

Just curiosity, do you just give the start button a quick single hit or hold it till the car starts? 2011 RRS HSE Luxury 3.0 TDV6 Fuji White on Ebony/Ivory
Born and raised in So Cal. Moved to the UK in 2018 for a few years. Now in Poland and looking at moving back to the UK.

Not able to comment on the L494, but it makes absolutely no difference to my old L320 if there is vacuum in the brake system or not it still starts first time.

Cheers
Col

Hi Drago,
How are you getting on with this problem? Having experienced similar I'm very interested to hear the outcome and how the problem has been sorted. Tim
RRS sold and replaced with a Skoda Kodiaq after appalling RR Dealer experience and LR inability to supply new cars in any sort of reasonable time frame..