I used the instructions from Ford workshop manual. Like I said earlier, I didn't take the time to thoroughly run through all the test points because some of the pintests called out in manual didn't match the connectors I have so I'm not going to rely on that information. Based on the symptoms I have (continuous tone), the manual suggests to check for corrosion or pushed out pins in each connector. That's my next step. If everything looks good from there, it says to install a new parking aid module(not gonna happen)