Legacy Sedan 2WD F4-2.2L SOHC (1990)
Coolant Temperature Sensor/Switch (For Computer): Testing and Inspection
COOLANT TEMPERATURE SENSOR DIAGNOSTIC CHART
Coolant Temperature Sensor Diagnostic Chart
A faulty coolant temperature sensor will set code 21 in the on-board diagnostic system. Refer to the schematic diagram and test the sensor with the
diagnostic chart.
Coolant Temperature Sensor Schematic
CHECK ECU VOLTAGE
With ignition "ON," measure voltage between ECU connector terminal (B48)7 and ground. It should measure 0.6 - 4.5V.
CHECK COOLANT TEMPERATURE SENSOR
Coolant Temperature Sensor Testing