I have been doing a few tests over the past couple of days to try and narrow the problem down.
Yesterday morning and the morning before that the car started fine. (Press ignition button once, wait approx 10 seconds, press again with brake and car starts.
This morning (-6 overnight) the car wouldn’t start with the same method. This took probably six tries before it kicked in to life.

Noticed on one of PowerfulUk’s video’s they mention that upon pressing the ignition button once the car then performs an ABS pressure check. If the check is not correct the car won’t start on the second press of the button with the brake pedal pressed down. (This potentially rules out a brake switch issue)

From what I can gather the problem my end seems to revolve around the temperature.
So maybe the cold weather plays a part in this “test” being carried out.
On the first press of the brake pedal first thing in the morning it’s not firm.
It’s after 2-3 presses that the pedal goes hard.
Now whether it’s just coincidence the brake pedal going hard, or this may play a role in the car not starting who knows?

Would be interesting to see if anyone with the same issues has the same scenario as above?

Started first time this morning no problems. Probably 0 degrees over night. Clearly them few extra degrees drop in temperature make a big difference for some reason.

You press the start button twice? I only hold the brake and press start once for a couple seconds. It decides how much time it needs to start and fires up every time. Pretty much how I start all keyless start cars.

Not sure on L494’s, but I think on L320’s if you press and hold the start button while holding the brake down it essentially forces it to start. May be worth trying. 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.

I press ignition button once (foot off brake) all lights come on dash car primes itself. Then foot on brake, press button second time car starts. Holding button in on second press makes no difference to me.

If I understand correctly press the button once with foot off the brake pedal, ignition comes on and vehicle checks the system for faults etc. once completed, foot on the brake pedal and press the stop/start button again vehicle should start, no need to continually hold the button, the lower the ambient temp the longer the delay the before it will start cranking once the button is pressed due to the glow plugs/cold start system having to do it's thing, with my L320 sometimes I do the check, sometimes I don't bother, no delay though because it is petrol so probably what may make that difference.

Cheers
Col

This is the exact process I follow, but as above when the second press is initiated (with foot on brake pedal) the ignition then goes off again (as if you didn’t have foot on brake).
Holding button in makes no difference.

This process above works first time every time normally, it’s only when the temp’s are in the minus this doesn’t work and takes multiple tries.

One of the obvious issues when temperatures drop is to blame the battery, but I have no low battery warning light or no cranking over issues when it actually lets it start.

Reading on some other LR forums (defender) others have had the same problem, but again no solution so far.

Starting to wonder if it could be a software issue, but again could cost ££ going to LR for it to make no difference.

Have you had the codes read to see if it has a fault registered, like possibly a failed glow plug or two.

Cheers
Col

This is from the L320 manual, nothing about pushing the start button twice:



Wonder if you may have a little water in the lines. Has the fluid been fully changed and system bled? 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.

Simple really, if you want the vehicle to do a system check first before starting, press the button once to switch ignition on without pressing the brake pedal to allow time for the check, if you then want the vehicle to start apply the foot brake and press the button again (hence pressing it twice) hopefully the vehicle should then start. If you are not bothered about the system check and just want to start the vehicle, just get into it, apply the foot brake and just press the button.

I have never seen anything in print from L/R that you need to do a system check first prior to starting the vehicle, but this was a story running around years ago that this was the procedure, but after all not exactly a Dreamliner is it, but as usual probably mis- information from some "armchair expert", sometimes I do, sometimes I don't and it has not had any detrimental effect on the vehicle one way or the other in over 10 years of ownership.

Cheers
Col

No error codes logged on car.
Same issue starting this morning (normal temperatures)

Car had a full brake fluid change a year or so back, never had any problems with brakes or potential air locks

So starting to think may be something to do with battery (car has been sat for approx 15hrs on drive since last driven)
I have ordered a battery jump start pack to use when car doesn’t start to either identify or rule out battery.

Regarding two presses of ignition, to me this is something you do regardless of what car.
In a car with a key and ignition barrel this would simulate first and second turn of key before starter turns over.

With the first button press, this gives the system a few seconds to prime before the starter engages.

When my car eventually refused to start at all the recovery guys checked out the battery and systems. There were no fault codes and battery was fully charged. As said before the garage eventually found a poor connection somewhere under the car but seemed unable to give me a clear explanation. A couple of weeks later the problem returned. 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 will have to double check some of the power cables under the car.
I have checked the junction box under the drivers side front wheel arch and all cables and crimped ends look fine and connections are free of corrosion and are tight.

I took car out for a good drive this evening, and cant remember the stop/start kicking in.
Will have to double check tomorrow, but wonder if this could be something to do with it?

Something to consider.
The stop/start on my car didn't work, however the car would start without problems and no other issues.
I changed the battery because the date stamped on the negative terminal identified it was original, from then on stop/start and all other functions work as normal.

Thanks for the info.
As I very rarely drive the car (it’s the better half’s daily drive) I just need to double check start/stop isn’t working as it only sprung to mind on return of a drive out.
Not sure if I have the second smaller battery or the capacitor (will have to check)

It’s not a system check, a pressure reading from the ABS pump tells the ECU that the pedal in depressed and then allows the car to start. Not the brake switch like most cars. The pedal goes hard due the stored vacuum being used up as you press the pedal. It would seem the pressure sensor in the ABS pump is simply not seeing enough pressure for whatever reason, to allow the car to start.