Information and Help Needed

I would go to the dealer with your VIN, have them print up the wiring diagram (they normally do this for free), and see what you need.

 

Sounds like you bought a used tank 3 years earlier. It's possible the sensor is bad in it.

 

I’ve had more problems with this sensor and the pigtail itself than anything else on my Freightliner/Detroit. Jump the plug, paperclip works best on mine. I’ve twisted wires together. Same thing. I don’t think it matters which way the wires go. If the code goes away . It’s usually the sensor. Usually can change them without losing much coolant. Work fast. Sometimes a good cleaning will do the trick. They get an invisible film on them sometimes.