Appreciate your help, this gives me something to work with.
I was expecting the output of the PPS ECU to the solenoid to be 12V but I will verify.
I found a post on a forum of someone who got it to work but there wasn't enough info, just the measured voltages whilat driving and something about using a 5V supply to the solenoid and not getting enough steering assistance and then using an 8V supply