200 Quattro Wagon L5-2226cc 2.22L SOHC Turbo (MC) (1989)
Coolant Temperature Sensor/Switch (For Computer): Testing and Inspection
Coolant Temperature Signal, Checking
CIS Turbo ECU Harness Connector (Pin # Locations)
CIRCUIT TEST
Test conditions: Engine temperature at least 20~C (68~F).
1.
Disconnect harness connector from ECU.
Coolant Temperature Sensor
2.
Using DVM, check resistance between terminal #10 of harness connector and ground.
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Resistance should be approximately that shown in diagram for a given temperature.
If resistance is higher than specified (or infinite), check for:
a. Poor connections or corroded connector terminal at sensor.
b. Open circuit between ECU terminal #10 and sensor.
c. Faulty sensor.
If resistance is lower than specified (or zero), check for:
a. Grounded circuit between ECU terminal #10 and sensor.
b. Faulty sensor.
SENSOR TEST