P2181 – Cooling System Performance


When somewhere in the engine, the temperature is out of range, the P2181 happens
The P2181 is triggered when somewhere in the engine, the temperature is out of range

A vague OBD2 code, the P2181 suggests that there’s somewhere in the engine where the temperature is out of range (either too hot or too cold).

Main Symptoms:

  • Check Engine Light comes on
  • Temperature gauge indicates too high or too low temp
  • If the temp is too cold the engine will have a rich condition

Possible Causes:

  • Defective engine coolant temperature (ECT) sensor
  • Wiring or connector problem in ECT circuit
  • Thermostat is stuck open or closed
  • Presence of air in cooling system
  • Low engine coolant level

Diagnostic Steps:

  • If the engine is running too cold replace thermostat
  • Check to ensure there are no open, broken, disconnected, shorted or burnt wires and connectors in ECT circuit
  • Check whether fan is working. If it’s wobbling or has a leak tighten or replace the fan. Remember to check its fuse as well
  • Test the resistance of ECT sensor. If it’s off the recommended reading replace the sensor

Read More: OBD2 Codes List: Meaning, Fixes, and Free Download