Not sure if this is the norm or not?! I bought a Bluetooth unit and loom. I've just taken apart my car and plugged in the new loom and unit but when I turned on my head unit it asked for a 4 digit code. When I plugged the normal wiring back in it didn't ask for a code?! Any ideas?

Seems odd and might suggest a wire is missing from the BT loom.

One thing to eliminate though is whether the code gets read from the cluster after a couple of minutes with the BT loom plugged in, rather than immediately.

Just a thought as I have seen this with other stereos in one or two VAG cars.

Leave it until tomorrow and it'll probably be OK.

I've had it occasionally when removing my Columbus. But as the code is stored in the car, it soon figures it out.

Lol unplugged it all now!!

I'll try again tomorrow!