D4 won’t start

[dwaters]

Hi all, chasing some help please. Last night I went to start my car to drive home after a meeting but the car would not start. I thought it was the brake locking it out but I could see this was working each time I pressed the brake. All the lights on the dash would light up but just no ignition. Both batteries were fine and RAC confirmed this also. I disconnected both batteries for approx 5 mins but still no luck. I ended up getting it towed home so had to manually select neutral to get it on the tow truck then back into park when it arrived home. Still won’t start. I have no idea as it has been fine all day. I have not driven off road or through any puddles. It’s a 2016 tdv6 FYI. Would love to hear your thoughts. Thanks

[DiscoJeffster]

You need to get the codes read to determine the issue

[dwaters]

I had RAC check the fault code and there were none.
No faults on dash either.

[Graeme]

The stop/start button can fail in this manner and IIRC a faulty brake light switch can also cause this.

[dwaters]

Thanks mate, the stop start seems to work as all the accessory light come on.
The brake light switch appears to be working as I can see the warning come up on the dash when I take my foot off the brake. I did also manually exercise the switch too but still not ruling it out as I think there are multiple contacts on this switch and although the one to dash seems to work, the one to the ecu may have failed.

[DiscoJeffster]

I had RAC check the fault code and there were none.
No faults on dash either.

Get it to a specialist with a more Land Rover focused diagnostic tool would be my advice.

[dwaters]

Yep that’s what I am doing. It’s on the tow truck now……]

[mowog]

Did you try the emergency start procedure?

On the lower part of the steering column right side there are 3 lines Hold the key against that and try.

I had no start and no smart key found. My KVM module had failed.

[Graeme]

I think there are multiple contacts on this switch and although the one to dash seems to work, the one to the ecu may have failed.

Yes, 2 sets of contacts. One learns to carry a spare switch.

[dwaters]

Thanks for the reply and no I didn’t try that but it seems to recognise when the smart key is within range as I tried starting it without the key in range and the smart key not in range came up on the dash.
Vehicle is on its way to the specialist do I am hoping it’s an easy fix.
Possibly the brake switch?
Thanks