Diagnostic Procedure
DIAGNOSTIC PROCEDURE FOR DTC 221. CHECK VOLTAGE OF SENSOR.
^ If OK check for momentary interruption.
^ If not OK proceed to step 2.
2. CHECK RESISTANCE OF SENSOR.
^ If OK proceed to step 3.
^ If not OK replace engine coolant temperature sensor.
3. CHECK FOR OPEN AND SHORT IN HARNESS AND CONNECTOR BETWEEN ENGINE CONTROL MODULE AND ENGINE COOLANT TEMPERATURE SENSOR.
^ If OK check and replace ECM.
^ If not OK repair or replace harness or connector.
NOTE: If DTC 22 (engine coolant temperature sensor circuit), 24 (intake air temperature sensor circuit) and 41 (throttle position sensor circuit) are output simultaneously, E2 (sensor ground) may be open.