Diagnostic Aids

WARNING: This page is about a different car, the 2003 Pontiac Grand Am, 2003 Oldsmobile Alero, 2003 Chevrolet Monte Carlo, and 2003 Chevrolet Impala. However, it is still accessible from the selected car via links, so may be relevant.

DTC P0116 is designed to detect an ECT sensor that is skewed high.
An IAT sensor that is skewed low could cause this DTC to set.
When inspecting the ECT sensor, the Temperature vs. Resistance table should be used in order to determine if a skewed sensor is the problem. See TEMPERATURE VS. RESISTANCE table.
If the engine has been allowed to sit overnight, the ECT and IAT temperature should be within the calculated amount.