P0513 - land rover discovery 3, common faults? quick checks?

Question

Intermittent no start;
Doors lock/unlock using key remote
Engine cranks but won't fire
16 fault codes logged, according to Land Rover's TSB,
Only 3 of these are "hard" codes ie:
-P0513 Incorrect Immobilizer Key
-P0826 Up &Down Shift Switch Circuit
-C1A00 Control Module (I'm not 100% sure this is a hard code)

The rest are all "U" prefix 'Lost communication' codes

I am focusing on the hard codes first, so any info on these would be great
Thanks

Answer 1

P0513 incorrect imobilizer key

Thats fine you can unlock the door with the remote, the ignition needs to see a valid key signal, the intermittent start can be coming from problem in the ignition switch