P0117

DTC P0117, P0118 ECT SENSOR





Component Description





The engine coolant temperature sensor is used to detect the engine coolant temperature. The sensor modifies a voltage signal from the ECM. The modified signal returns to the ECM as the engine coolant temperature input. The sensor uses a thermistor which is sensitive to the change in temperature. The electrical resistance of the thermistor decreases as temperature increases.





[Reference data]









On Board Diagnosis Logic
These self-diagnoses have the one trip detection logic.






FAIL-SAFE MODE
When the malfunction is detected, the ECM enters fail-safe mode and the MIL illuminates.









DTC Confirmation Procedure
1. If DTC Confirmation Procedure has been previously conducted, always perform the following procedure before conducting the next test.
a. Turn ignition switch OFF and wait at least 10 seconds.
b. Turn ignition switch ON.
c. Turn ignition switch OFF and wait at least 10 seconds.
2. Turn ignition switch ON and wait at least 5 seconds.
3. Check DTC.
4. If DTC is detected, go to P0117.




Wiring Diagram









Diagnosis Procedure
1.CHECK GROUND CONNECTIONS
1. Turn ignition switch OFF.
2. Loosen and retighten ground screws on the body. Power Supply and Ground Circuit.










OK or NG
OK - GO TO 2.
NG - Repair or replace ground connections.
2.CHECK ECT SENSOR POWER SUPPLY CIRCUIT
1. Disconnect engine coolant temperature (ECT) sensor harness connector.










2. Turn ignition switch ON.





3. Check voltage between ECT sensor terminal 1 and ground with
CONSULT-III or tester.

Voltage: Approximately 5 V

OK or NG
OK - GO TO 4.
NG - GO TO 3.
3.DETECT MALFUNCTIONING PART
Check the following.
- Harness connector F291, F50
- Harness for open or short between ECM and engine coolant temperature sensor
- Repair open circuit or short to ground or short to power in harness or connectors.
4.CHECK ECT SENSOR GROUND CIRCUIT FOR OPEN AND SHORT
1. Turn ignition switch OFF.
2. Disconnect ECM harness connector.
3. Check harness continuity between ECT sensor terminal 2 and ECM terminal 67. Refer to Wiring Diagram.

Continuity should exist.

4. Also check harness for short to ground and short to power.
OK or NG
OK - GO TO 6.
NG - GO TO 5.
5.DETECT MALFUNCTIONING PART
Check the following.
- Harness connector F291, F50
- Harness for open and short between ECT sensor and ECM
- Repair open circuit or short to ground or short to power in harness or connectors.
6.CHECK ENGINE COOLANT TEMPERATURE SENSOR
P0117.
OK or NG
OK - GO TO 7.
NG - Replace engine coolant temperature sensor.
7.CHECK INTERMITTENT INCIDENT
Diagnosis Procedure.
- INSPECTION END




Component Inspection

ENGINE COOLANT TEMPERATURE SENSOR





1. Check resistance between engine coolant temperature sensor terminals 1 and 2 as shown in the figure.





[Reference data]





2. If NG, replace engine coolant temperature sensor.




Removal and Installation

ENGINE COOLANT TEMPERATURE SENSOR
Component.