P1116

I am getting Engine Code P1116, Coolant Temperature Sensor Circuit Stuck for Coolant Heat Storage System. I checked the power connection to the Coolant Temperature sensor, it looks fine. I replaced the sensor itself, the one that is connected to CHS tank. Bleed the air out of the tank, I am getting a consistency CHS Pump reading of 2.99 or 3.00 on the multimeter, when I am manually turning pump to bleed the air. I still could not resolve the code. Can anyone suggest if I should replace the coolant engine thermostat at this point? Thanks

 

It was hard to believe, but the problem was the plumbing connection to the three-way cooling valve. Reviewed the pattern and with lots of difficult work removing clamps in a tight space finally, the problem solved. no more engine code P0116