Engine Control System

DTC 21 Engine Coolant Temperature Sensor Diagnostic Chart:

Engine Coolant Temperature Sensor Circuit:

DIAGNOSTIC CHART AND DIAGRAM

Engine Coolant Temperature Sensor:

1. CHECK WATER TEMPERATURE SENSOR. Remove collector cover and air intake boot.
1)Disconnect connector from water temperature sensor.
2)Measure resistance between water temperature sensor connector terminals.

Connector & Terminal/Specified value
No. 1 - No. 2/2.0 - 3.0 k ohms [2O°C (68°F)]
No. 1 - No. 2/0.3 - 0.4 k ohms [80°C (176°F)]

2. CHECK HARNESS CONNECTOR BETWEEN ECU AND WATER TEMPERATURE SENSOR.
1) Disconnect ECU connectors.
2) Measure resistance between ECU connector and water temperature sensor.

Connector & Terminal/Specified value
(B59) No. 3 - (E24) No. 1/0 ohms
(B59) No. 21 - (E24) No. 2/0 ohms