Be sure you plugged in all the harness wires correctly. If they are, the Probe light indicates that the board senses a temp probe in the socket. Generally running a selfclean cycle or over time, the temp probe jack gets little use, and the contacts can become corroded or oxidized. To remedy this, I usually have good luck by inserting the temp probe after spraying a dot of WD-40 into the hole. If you've never used the temp probe before, the jack is on the ceiling in the front left side of the oven cavity.
If you lost your temp probe or can't find it, any old guitar jack will do to exercise the contacts. Spray, then run the jack in and out a few times...in and out...in and , uh well, you get the picture.
This usually solves the resistance issue for the jack. Normally the two contacts are supposed to be closed unless the jack is plugged in. In extreme cases, I have had to replace the jack. The current part number for the jack (receptacle) is 74009649. It may be hard to find...See Item #8 on This Diagram