Diagnostic Aids

DTC P0116 is designed to detect an ECT sensor that is skewed high.
An IAT sensor that is skewed could cause this DTC to set.
When checking the ECT sensor, the Temperature vs Resistance table should be used in order to determine if a skewed sensor is the problem. See SENSOR OPERATING RANGE CHARTS - TRUCKS article.
If the engine has been allowed to sit overnight, the ECT and IAT temperature should be within the calculated amount.