6K RPM Fans Shortly after Logging In

Hello, I'm hoping someone may have some ideas here...

My fans are full on and when doing a HW Diagnostics I'm getting the following error:

4SNS/1/40000000: TsOP

Searching google wasn't entirely conclusive, but it appears that I may have a temperature sensor failure. TsOP appears to point to the Proximity Temperature Sensor. I've open the chassis and double checked to make sure that the left and right sensor wires haven't come undone and they look good.

So this leads me to two questions:

1. Does anyone know which temperature sensor has failed?
2. Any ideas on where to find such sensor (iFixIt doesn't appear to sell them and eBay only has 3 available for the Santa Rosa based systems).

Thanks in advance!