XT 4WD F4-1781cc 1.8L SOHC (1990)
Coolant Temperature Sensor/Switch (For Computer): Testing and Inspection
Coolant Temperature Sensor Schematic
A faulty coolant temperature sensor will set code 21 in the on-board diagnostic system. Refer to the schematic diagram and test the coolant sensor with
the diagnostic chart.
Wire color code identification:
L:
Blue
B:
Black
Y:
Yellow
G:
Green
R:
Red
W: White
Br: Brown
Lg: Light green
Gr: Gray
Coolant Temperature Sensor Diagnostic Chart
COOLANT TEMPERATURE SENSOR DIAGNOSTIC CHART