Accessing keyless wiring

[HDS]

I got some problems with the keyless entry on my 2007 Yaris. It's acting weird and sometimes the indicators get stuck blinking as if the hazards are on, pressing the remote stops it. The drivers side door no longer responds either.

I've read that the wiring can corrode near the door hinges, I had assumed that meant the wiring was exposed behind the fender so I removed the front wheel and the inner fender and then found another protective plate. And when removed that I found nothing.

How do I access the wiring to inspect it, do I need to get at it from the inside, or do I need to remove the inner door panel?