2002 VW Jetta
Check Engine light is on.
Trouble code: P2181 (18613).
The Engine Control Module monitors the Engine Coolant Temperature Sensor signal to determine the engine temperature.
The ECM sets the OBDII code when the Engine Coolant Temperature Sensor signal is out of factory specifications.
Possible causes:
Low coolant level
Faulty Engine Coolant Temperature Sensor
Stuck or leaking thermostat
Engine Coolant Temperature Sensor harness is open or shorted
Engine Coolant Temperature Sensor circuit poor electrical connection