P0118
2GR-FE ENGINE CONTROL SYSTEM: SFI SYSTEM: P0115: Engine Coolant Temperature Circuit Malfunction
DTC P0115 - Engine Coolant Temperature Circuit Malfunction
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 entering the following menus on the Techstream: Powertrain / Engine / 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 drops, the resistance in the thermistor increases. When the temperature rises, the resistance drops. These variations in resistance are reflected in the output voltage 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 output voltage 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 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: Read freeze frame data using the 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 Freeze Frame Data.
PROCEDURE
1. CHECK DTC OUTPUT
(a) Connect the Techstream to the DLC3.
(b) Turn the engine switch on (IG).
(c) Select the following menu items: Powertrain / Engine / Trouble Code.
(d) Read the DTCs.
Result:
C -- CHECK HARNESS AND CONNECTOR (ENGINE COOLANT TEMPERATURE SENSOR - ECM)
B -- CHECK HARNESS AND CONNECTOR (ENGINE COOLANT TEMPERATURE SENSOR - ECM)
A -- Continue to next step.
2. READ VALUE USING ENGINE COOLANT TEMPERATURE SENSOR (COOLANT TEMP)
(a) Connect the Techstream to the DLC3.
(b) Turn the engine switch on (IG).
(c) Turn the Techstream on.
(d) Enter the following menus: Powertrain / Engine / Data List / Coolant Temp.
(e) Read the value displayed on the Techstream.
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).
C -- CHECK FOR INTERMITTENT PROBLEMS
B -- CHECK ENGINE COOLANT TEMPERATURE SENSOR (CHECK FOR SHORT IN SENSOR)
A -- Continue to next step.
3. CHECK ENGINE COOLANT TEMPERATURE SENSOR (CHECK FOR OPEN IN SENSOR)
(a) Confirm good connection of the sensor.
(b) Disconnect the B13 engine coolant temperature (ECT) sensor connector.
(c) Connect terminals 1 and 2 of the ECT sensor connector on the wire harness side.
(d) Connect the Techstream to the DLC3.
(e) Turn the engine switch on (IG).
(f) Turn the Techstream on.
(g) Enter the following menus: Powertrain / Engine / Data List / Coolant Temp.
(h) Read the value displayed on the Techstream.
Standard:
140°C (284°F)
(i) Reconnect the ECT sensor connector.
OK -- REPLACE ENGINE COOLANT TEMPERATURE SENSOR
NG -- Continue to next step.
4. CHECK HARNESS AND CONNECTOR (ENGINE COOLANT TEMPERATURE SENSOR - ECM)
(a) Disconnect the B13 ECT sensor connector.
(b) Disconnect the B12 ECM connector.
(c) Measure the resistance between the terminals.
Standard resistance:
(d) Reconnect the ECM connector.
(e) Reconnect the ECT connector.
NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- REPLACE ECM
5. CHECK ENGINE COOLANT TEMPERATURE SENSOR (CHECK FOR SHORT IN SENSOR)
(a) Disconnect the B13 ECT sensor connector.
(b) Connect the Techstream to the DLC3.
(c) Turn the engine switch on (IG).
(d) Turn the Techstream on.
(e) Enter the following menus: Powertrain / Engine / Data List / Coolant Temp.
(f) Read the value displayed on the Techstream.
Standard:
-40°C (-40°F)
(g) Reconnect the ECT sensor connector.
OK -- REPLACE ENGINE COOLANT TEMPERATURE SENSOR
NG -- Continue to next step.
6. CHECK HARNESS AND CONNECTOR (ENGINE COOLANT TEMPERATURE SENSOR - ECM)
(a) Disconnect the B13 ECT sensor connector.
(b) Disconnect the B12 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.
NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- REPLACE ECM