P0118

2TR-FE ENGINE CONTROL SYSTEM: SFI SYSTEM: P0115: Engine Coolant Temperature Circuit

DTC P0115 - Engine Coolant Temperature Circuit

DTC P0117 - Engine Coolant Temperature Circuit Low Input

DTC P0118 - Engine Coolant Temperature Circuit High Input

DESCRIPTION

A thermistor is built into the Engine Coolant Temperature (ECT) sensor, of which the resistance value varies according to the ECT.
The structure of the sensor and connection to the ECM is the same as the Intake Air Temperature (IAT) sensor.

HINT: When any of DTCs P0115, P0117 and P0118 are set, the ECM enters fail-safe mode. During fail-safe mode, the ECT is estimated to be 80°C (176°F) by the ECM. Fail-safe mode continues until a pass condition is detected.





HINT: When any of these DTCs are set, check the ECT by electing the following menus on the Techstream: Powertrain / Engine and ECT / Data List / All Data / Coolant Temp.





MONITOR DESCRIPTION

The ECT sensor is used to monitor the engine coolant temperature. The ECT sensor has a thermistor that varies its resistance depending on the temperature of the engine coolant. When the coolant temperature is low, the resistance in the thermistor increases. When the temperature is high, the resistance drops. The variations in resistance are reflected in the voltage output from the sensor. The ECM monitors the sensor voltage and uses this value to calculate the ECT. When the sensor output voltage deviates from the normal operating range, the ECM interprets this as a fault in the ECT sensor and sets a DTC.
Example:
If the sensor voltage output is more than 4.91 V for 0.5 seconds or more, the ECM determines that there is an open in the ECT sensor circuit, and sets DTC P0118. Conversely, if the voltage output is less than 0.14 V for 0.5 seconds or more, the ECM determines that there is a short in the sensor circuit, and sets DTC P0117.
If the malfunction is not repaired successfully, a DTC is set 0.5 seconds after the engine is next started.

MONITOR STRATEGY





TYPICAL ENABLING CONDITIONS





TYPICAL MALFUNCTION THRESHOLDS

P0115:





P0117:





P0118:





COMPONENT OPERATING RANGE





WIRING DIAGRAM





INSPECTION PROCEDURE

HINT:
- If other DTCs relating to different systems that have terminal E2 as the ground terminal are output simultaneously, terminal E2 may have an open circuit.

- Read freeze frame data using the Techstream. Freeze frame data records the engine condition when malfunctions are detected. When troubleshooting, freeze frame data can help determine if the vehicle was moving or stationary, if the engine was warmed up or not, if the air-fuel ratio was lean or rich, and other data from the time the malfunction occurred.

PROCEDURE

1. READ DATA LIST (ENGINE COOLANT TEMPERATURE)
(a) Connect the Techstream to the DLC3.
(b) Turn the ignition switch to ON and turn the Techstream ON.
(c) Enter the following menus: Powertrain / Engine and ECT / Data List / All Data / Coolant Temp.
(d) Read the value displayed on the tester.
Standard:
Between 80°C and 97°C (176°F and 207°F) with warm engine.
Result:





HINT: If there is an open circuit, the Techstream indicates -40°C (-40°F).

If there is a short circuit, the Techstream indicates 140°C (284°F).

C -- CHECK FOR INTERMITTENT PROBLEMS
B -- READ DATA LIST (CHECK FOR SHORT IN WIRE HARNESS)
A -- Continue to next step.
2. READ DATA LIST (CHECK FOR OPEN IN WIRE HARNESS)





(a) Disconnect the E2 Engine Coolant Temperature (ECT) sensor connector.
(b) Connect terminals 1 and 2 of the ECT sensor connector on the wire harness side.
(c) Connect the Techstream to the DLC3.
(d) Turn the ignition switch to ON and turn the Techstream ON.
(e) Enter the following menus: Powertrain / Engine and ECT / Data List / All Data / Coolant Temp.
(f) Read the value displayed on the tester.
Standard:
140°C (284°F)
(g) Reconnect the ECT sensor connector.
OK -- CONFIRM GOOD CONNECTION TO SENSOR. IF OK, REPLACE ENGINE COOLANT TEMPERATURE SENSOR
NG -- Continue to next step.
3. READ DATA LIST (CHECK FOR OPEN IN ECM)





(a) Disconnect the E2 ECT sensor connector.
(b) Connect terminals THW of the E2 of the ECM connector.

HINT: Before checking, do a visual and contact pressure check for the ECM connector.

(c) Connect the Techstream to the DLC3.
(d) Turn the ignition switch to ON and turn the Techstream ON.
(e) Enter the following menus: Powertrain / Engine and ECT / Data List / All Data / Coolant Temp.
(f) Read the value displayed on the tester.
Standard:
140°C (284°F)
(g) Reconnect the ECT sensor connector.
NG -- CONFIRM GOOD CONNECTION TO ECM. IF OK, REPLACE ECM
OK -- REPAIR OR REPLACE HARNESS OR CONNECTOR
4. READ DATA LIST (CHECK FOR SHORT IN WIRE HARNESS)





(a) Disconnect the E2 ECT sensor connector.
(b) Connect the Techstream to the DLC3.
(c) Turn the ignition switch to ON and turn the Techstream ON.
(d) Enter the following menus: Powertrain / Engine and ECT / Data List / All Data / Coolant Temp.
(e) Read the value displayed on the tester.
Standard:
-40°C (-40°F)
(f) Reconnect the ECT sensor connector.
OK -- REPLACE ENGINE COOLANT TEMPERATURE SENSOR
NG -- Continue to next step.
5. READ DATA LIST (CHECK FOR SHORT IN ECM)





(a) Disconnect the E4 ECM sensor connector.
(b) Connect the Techstream to the DLC3.
(c) Turn the ignition switch to ON and turn the Techstream ON.
(d) Enter the following menus: Powertrain / Engine and ECT / Data List / All Data / Coolant Temp.
(e) Read the value displayed on the tester.
Standard:
-40°C (-40°F)
(f) Reconnect the ECM sensor connector.
NG -- REPLACE ECM
OK -- REPAIR OR REPLACE HARNESS OR CONNECTOR