Thanks for your reply. Yes there are five pins: four on one length and one on the bottom as per the picture below.
What I’m not sure about is:
1. the wire colour ordering
2. the correct holes for the wires
When I purchased the car the ECM never had power going to it. I’ve never touched the wires until trying to change the unit last week. When I removed the old connector I saw that the wires weren’t in far enough to make a connection so I’ve now pushed them in further but in the same holes they were aligned to. It hasn’t worked and seems to have knocked out the noise the car used to make when I put it into reverse!
I’m hoping if someone could just send a pic of the wire ordering I can then rearrange.