1, 5 Getz diesel engine cut out on high speed and cranks, but won't start

Mr expert. The glow plugs are new and the car will still start unless the diesel is below freezing point. The injection pump is ok.

2004 1.5 Getz diesel. After driving for 3 hours the engine cut out at 140 km/h. It cranks but will not start. Checked mechanical side, everything seems fine. What do I check on the electrical side. I have another, same Getz running at this stage and have parts available to replace and check. Where do I start. I have a problem with the Sanji remote. It will not lock and unlock the doors like it used to. When you push the button for the lock and unlock the indicators flash, but does not lock and unlock the doors. It used to lock the doors when ignition was switched on and unlock when turned off, but does not do that anymore. The problem with the remote started app 4 months ago and the car was running fine till now. If it has an override I do not know how to override it. Please help?