P0115
1GR-FE ENGINE CONTROL SYSTEM: SFI SYSTEM: P0115,P0117,P0118: Engine Coolant Temperature Circuit
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: Powertrain / Engine and ECT / Data List / All Data / 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 is low, the resistance in the thermistor increases. When the temperature is 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 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
CONFIRMATION DRIVING PATTERN
1. Connect the Techstream to the DLC3.
2. Turn the ignition switch to ON and turn the Techstream on.
3. Clear the DTCs (even if no DTCs are stored, perform the clear DTC operation).
4. Turn the ignition switch off and wait for at least 30 seconds.
5. Turn the ignition switch to ON and turn the Techstream on.
6. Wait 0.5 seconds or more.
7. Enter the following menus: Powertrain / Engine and ECT / Trouble Codes.
8. Read the DTCs.
HINT
* If a DTC is output, the system is malfunctioning.
* If a DTC is not output, perform the following procedure.
9. Enter the following menus: Powertrain / Engine and ECT / Utility / All Readiness.
10. Input the DTC: P0115, P0117 or P0118.
11. Check the DTC judgment result.
HINT
* If the judgment result shows NORMAL, the system is normal.
* If the judgment result shows ABNORMAL, the system has a malfunction.
12. If the test result is INCOMPLETE or UNKNOWN and no pending DTC is output, perform a universal trip and check for permanent DTCs DTC Check / Clear.
HINT
* If a permanent DTC is output, the system is malfunctioning.
* If no permanent DTC is output, the system is normal.
WIRING DIAGRAM
INSPECTION PROCEDURE
HINT
Read freeze frame data using the Techstream. Freeze frame data record 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 VALUE USING TECHSTREAM (ENGINE COOLANT TEMPERATURE)
(a) Connect the Techstream to the DLC3.
(b) Turn the ignition switch to ON.
(c) 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 Techstream.
Standard:
Between 75°C and 100°C (167°F and 212°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) or higher.
C -- CHECK FOR INTERMITTENT PROBLEMS 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 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.
(e) Turn the Techstream on.
(f) Enter the following menus: Powertrain / Engine and ECT / Data List / All Data / Coolant Temp.
(g) Read the value displayed on the Techstream.
Standard:
140°C (284°F) or higher
(h) Reconnect the ECT sensor connector.
NG -- READ VALUE USING TECHSTREAM (CHECK FOR OPEN IN ECM)
OK -- CONFIRM GOOD CONNECTION TO SENSOR. IF OK, REPLACE ENGINE COOLANT TEMPERATURE SENSOR Removal
3. READ VALUE USING TECHSTREAM (CHECK FOR OPEN IN ECM)
(a) Disconnect the ECT sensor connector.
(b) Connect terminals THW and ETHW of the ECM connector.
HINT
Before checking, do visual and contact pressure checks on the ECM connector.
(c) Connect the Techstream to the DLC3.
(d) Turn the ignition switch to ON.
(e) Turn the Techstream on.
(f) Enter the following menus: Powertrain / Engine and ECT / Data List / All Data / Coolant Temp.
(g) Read the value displayed on the Techstream.
Standard:
140°C (284°F) or higher
(h) Reconnect the ECT sensor connector.
NG -- CONFIRM GOOD CONNECTION TO ECM. IF OK, REPLACE ECM Removal
OK -- REPAIR OR REPLACE HARNESS OR CONNECTOR (ENGINE COOLANT TEMPERATURE SENSOR - ECM)
4. READ VALUE USING TECHSTREAM (CHECK FOR SHORT IN WIRE HARNESS)
(a) Disconnect the ECT sensor connector.
(b) Connect the Techstream to the DLC3.
(c) Turn the ignition switch to ON.
(d) 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 Techstream.
Standard:
-40°C (-40°F)
(g) Reconnect the ECT sensor connector.
NG -- READ VALUE USING TECHSTREAM (CHECK FOR SHORT IN ECM)
OK -- REPLACE ENGINE COOLANT TEMPERATURE SENSOR Removal
5. READ VALUE USING TECHSTREAM (CHECK FOR SHORT IN ECM)
(a) Disconnect the ECM connector.
(b) Connect the Techstream to the DLC3.
(c) Turn the ignition switch to ON.
(d) 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 Techstream.
Standard:
-40°C (-40°F)
(g) Reconnect the ECM connector.
NG -- REPLACE ECM Removal
OK -- REPAIR OR REPLACE HARNESS OR CONNECTOR (ENGINE COOLANT TEMPERATURE SENSOR - ECM)