Check Engine Light Code P0116

OBD II Code P0116
Engine Coolant Temperature Circuit Range/Performance Problem

Our emissions expert has put together the following information about the P0116 fault code. We have also included diagnostic procedures you can take to your repair shop if the mechanic is having difficulty analyzing the code.

OBD II Fault Code

OBD II P0116
Fault Code Definition
The Engine Coolant Temperature Sensor measures the rise and fall of the Engine Coolant Temperature. This provides critical data needed for the Powertrain Control Module (PCM) to control the Air Fuel Ratio, the Ignition Spark Timing, the cooling fans, and many components of the Emissions Control Systems. Code P0116 indicates a performance problem with the sensor signal to the Powertrain Control Module.

Symptoms

Check Engine Light will illuminate
In many cases, no abnormal symptoms may be noticed
In some cases, the engine may be hard starting and/or get poor fuel economy
Common Problems That Trigger the P0116 Code

Defective Engine Coolant Temperature Sensor
Rusty and/or corroded Engine Coolant
Faulty or corroded Engine Coolant Temperature wiring or connections

Common Misdiagnoses

Engine Coolant Temperature Sensor is replaced when the real cause is rusty coolant
Engine Coolant Temperature Sensor is replaced when the real cause is a poor connection or chafed wiring
Engine Coolant Temperature Sensor is replaced when the real problem is in the Cooling System