From those errors I'd be looking at an electrical connection issue first. Start unplugging and cleaning electrical contacts.
Primary culprits:
* Battery negative terminal
* Battery positive terminal
* Fusible link on battery positive terminal
* Battery negative connection to engine block
* ECU earth point on vehicle right hand side on engine guard
You could also (this part's easy!) remove and replace every fuse and relay you can see in the engine bay (there are 3 locations). Just pull it out and put it straight back in. Most common is the block near the battery, but there's another near the ABS unit that suffers (probably from the turbo that's nearby and heat rises ...).
I've only once heard that the electrical connector to the gearbox has been problematic, but if you do the same - unplug and replug it - that might clear it up.