Okay, you should definitely be reading 5volts on one of the wires when the sensor is unplugged. It looks like the Yellow wire should read 5volts, the other wire is the sensor ground through the ECM, there is a TSB that came up, I will post it, I havent gone through the entire bulleting yet, but it does mention a bypass hose that it supposed to help with airlock, which will cause the ECT to read incorrectly if air is trapped at the sensors location, ECTs cannot read the temperature of air, only liquid, but a low 5volt reference is concerning as well. One temp sensor is located on the front of the engine and the other on the rear (diagram 2) just above the flywheel area. This is the OEM wiring diagram that also shows two temp sensors, you may need to cycle the key for the temperature to change, or it might be the other sensor, I'm not 100% sure on the two sensors, if that's for a different engine setup, but it's just what I'm seeing, let me post this TSB though, I think it will resolve your coolant issue.
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Tuesday, December 3rd, 2024 AT 11:31 AM