There was some discussion last night in the V6 MR2 Facebook group that I thought I would share here as well. I didn't know this was a thing, but for the last 6 or so years I've been using this 3 pin coolant sensor on my engine. I had my harness made by Doug (WireGap Inc.) and that's the way it came back to me. The advantage to this sensor is that it combines the signal for the ECU and the signal for the cluster into one sensor. I found the sensor on a Toyota Echo in the junkyard, but when I search for the part number it also comes up on some 2azfe Camrys.