Van wont start, flashing coil light.

[Dwuk2000]

My van (2017 T6) currently has an issue starting, it has a flashing coil light and nothing happens when you turn the key. Read the codes in Carista and it shows Manufacturer specific code of 16198 and when reset it returns.
Could start the van some times if I jump start it, so changed the battery for a new one (Bosch S5A13) yesterday and it started 3 out of 5 times (twice it just clicked), today it wont start with same symptoms, battery is fully charged.
I've also checked the Starter motor is getting power/signal, checked earths and at a loss why it is sporadic.
Any ideas what the issue is as have been through all the threads on this and can't find the error code anywhere.

 

[Loz]

Check the earth strap between the chassis and engine (look down the left-hand side of the engine).

Also, try using the neg lead of your jump leads to join the battery negative terminal to the engine block.

 

[Dwuk2000]

Cheers, Tried that before the battery change and no change, connections look fine on the left. Not unconnected them yet, will have a look when not working

I tried it 30 minutes ago with the jump lead connected and it started a few times, but just gone out during lunch and it now won't start with jump cables, just clicks then shows the flashing coil again.

 

[Loz]

Cheers, Tried that before the battery change and no change, connections look fine on the left. Not unconnected them yet, will have a look when not working

I tried it 30 minutes ago with the jump lead connected and it started a few times, but just gone out during lunch and it now won't start with jump cables, just clicks then shows the flashing coil again.

Sounds like the contact in the main solenoid (Part on top of the starter) has burnt out. Probably a new starter in that case.