Possibly engine coolant temp sensor ? Could be sending wrong info to ECU but often trips a code if dud . I'm sure you will get some more , better and informative advice from our Aussie car expert when he is next on the forum and sees your post .
What CCA rating is the battery and what brand is it ? What checks have you done on the battery and how old is it? Check the battery terminals and earth and starter connections. Colder weather will have a big impact on a weak, low CCA or dying battery as will any terminal or earth connections. There are no coolant sensors in that car that will effect starting. Also If it cranks at normal speed but does not start first try it may also be an issue with ignition or fuel check for: A. a corroded fuel rail leaking fuel at rest - not uncommon); B. any parasitic drain (i.e. glove box, interior light or boot light staying on) that may be partially flattening the battery. C. a faulty ICC ; this is fairly rare but on the B series the as the car is switched off the the ICC essentially goes through 3 stages of shut down, 15min,30min and final 45min each draws lower currents from the battery and on some cars it stays at the 1st stage (basically leaving the radio and full icc functions “live” but with the display screen off and hang there and drains the battery). Removing fuse 23 when switching off the car; basically cutting all power to the icc and stopping this parasitic drain and is a way to test for this fault.
Also try heating the PCM (Power Control Module) in the engine bay with a hair dryer or hot water bottle before trying to start; some of them have been know to become temperature sensitive so need warming before working. They die eventually so if that's the case and all it's earths and other connections are sound, you may have to replace it. Sometimes is just insulating corrosion on the earth ground on the PCM so check and clean that first you find a cold sensitive PCM.