P0117

2GR-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 its connection to the ECM are the same as those of 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 selecting the following menu items on Techstream: Powertrain / Engine and ECT / Data List / Coolant Temp.





MONITOR DESCRIPTION

The Engine Coolant Temperature (ECT) sensor is used to monitor the ECT. The ECT sensor has a thermistor with a resistance that varies according to the temperature of the engine coolant. When the coolant temperature becomes low, the resistance in the thermistor increases. When the temperature becomes high, the resistance drops.
These 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 -40°C (-40°F) 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 more than 140°C (284°F) 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 Techstream. The ECM records vehicle and driving condition information as freeze frame data the moment a DTC is stored. When troubleshooting, freeze frame data can be helpful in determining whether the vehicle was running or stopped, whether the engine was warmed up or not, whether the air-fuel ratio was lean or rich, as well as other data recorded at the time of a malfunction.

PROCEDURE

1. READ VALUE USING TECHSTREAM (ENGINE COOLANT TEMPERATURE)
(a) Connect Techstream to the DLC3.
(b) Turn the ignition switch to the ON position.
(c) Turn the tester on.
(d) Select the following menu items: Powertrain / Engine and ECT / Data List / Coolant Temp.
(e) 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, Techstream indicates -40°C (-40°F).
- If there is a short circuit, Techstream indicates 140°C (284°F) or higher.

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





(a) Disconnect the E12 Engine Coolant Temperature (ECT) sensor connector.
(b) Connect terminals 1 and 2 of the ECT sensor connector on the wire harness side.
(c) Connect Techstream to the DLC3.
(d) Turn the ignition switch to the ON position.
(e) Turn the tester on.
(f) Select the following menu items: Powertrain / Engine and ECT / Data List / Coolant Temp.
(g) Read the value displayed on the tester.
Standard:
140°C (284°F) or higher
(h) Reconnect the ECT sensor connector.
OK -- REPLACE ENGINE COOLANT TEMPERATURE SENSOR
NG -- Continue to next step.
3. CHECK HARNESS AND CONNECTOR (ENGINE COOLANT TEMPERATURE SENSOR - ECM)





(a) Disconnect the E12 ECT sensor connector.
(b) Disconnect the E9 ECM connector.
(c) Measure the resistance according to the value(s) in the table below.
Standard resistance:





(d) Reconnect the ECM connector.
(e) Reconnect the ECT connector.
OK -- REPAIR OR REPLACE HARNESS OR CONNECTOR (ENGINE COOLANT TEMPERATURE SENSOR - ECM)
NG -- REPLACE ECM
4. READ VALUE USING TECHSTREAM (CHECK FOR SHORT IN WIRE HARNESS)





(a) Disconnect the E12 ECT sensor connector.
(b) Connect Techstream to the DLC3.
(c) Turn the ignition switch to the ON position.
(d) Turn the tester on.
(e) Select the following menu items: Powertrain / Engine and ECT / Data List / Coolant Temp.
(f) Read the value displayed on the tester.
Standard:
-40°C (-40°F)
(g) Reconnect the ECT sensor connector.
OK -- REPLACE ENGINE COOLANT TEMPERATURE SENSOR
NG -- Continue to next step.
5. CHECK HARNESS AND CONNECTOR (ENGINE COOLANT TEMPERATURE SENSOR - ECM)





(a) Disconnect the E12 ECT sensor connector.
(b) Disconnect the E9 ECM connector.
(c) Measure the resistance according to the value(s) in the table below.
Standard resistance:





(d) Reconnect the ECT sensor connector.
(e) Reconnect the ECM connector.
OK -- REPAIR OR REPLACE HARNESS OR CONNECTOR (ENGINE COOLANT TEMPERATURE SENSOR - ECM)
NG -- REPLACE ECM