Update - I don't drive the car often, so i started to this week every day, now that I have the ELM227 and forscan back in my possession to try and get more info on this issue.
Finally, today (day 4 of driving it) the issue occurred. This time it was again at low speed, but I could hear clicking from the rear right (Near battery - I have a gutted interior so noises are louder than normal) and then shortly after that the brakes/ABS engaged. After I got off the brake, and drove away they engaged again (not on brakes at all, but when accelerating), but i was still turning out of a driveway. (steering not straight). It happened with advance trak switched on. Every time this happens, the engagement is very intermittent. The pedal pulse like normal ABS engagement, but it is very on and off, not constant on, constant off. It kinda cycles a few times over the course of each stop the car makes. Also, this seems to only occur at 10mph or less (thank god)
Forscan shows the following codes in the ABS module:
C1278 Steering Wheel Angle 1 and 2 Signal Fault
U1073 Engine Coolant Temp Sensor
U1262 SCP Data Link Fault
C1805 Mismatched PCM
B2900 VIN Mismatch
(No idea about those last two, and Forscan suggest the "U" codes aren't always problem indicators. So I am focusing on the first right now)
Guidance from the Scan app:
"This code is set when the calculated steering wheel angle is greater than 15 degrees while the steering is in the straight ahead position.
This may be caused by:
Misalignment of steering system
insecurely mounted sensor
Excessive wear in the steering system"
Any idea on where to start diagnosing next?