DTC P0116: ECT Sensor Circuit Range/Performance Problem (2002-2004 models)

NOTE: If DTC P0117 and/or P0118 are stored at the same time as DTC P0116, troubleshoot those DTCs first, then recheck for DTC P0116.

Turn the ignition switch ON (II).
Check the ECT with a scan tool or the HDS.
Is about 176°F (80°C) or higher, or 0.86 V or less indicated?
1. YES - Go to step 3.
2. NO - Go to step 7.
Note the coolant temperature from step 2.
Turn the ignition switch OFF.
Cool the engine for 1 hour.
Check the ECT with a scan tool or the HDS.
Did the ECT change 3.6°F (2°C) or more?
1. YES - Intermittent failure, system is OK at this time. Check the thermostat and the cooling system.
2. NO - Replace the ECT sensor (see CKP SENSOR REPLACEMENT ).
Note the coolant temperature from step 2.
Start the engine. Hold the engine speed at 3,000 RPM without load (in Park or neutral) until the radiator fan comes on, then let it idle.
Check the ECT with a scan tool or the HDS.
Does the ECT change 3.6°F (2°C) or more?
1. YES - Intermittent failure, system is OK at this time. Check the thermostat and the cooling system.
2. NO - Replace the ECT sensor (see CKP SENSOR REPLACEMENT ).