P0115
2UZ-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 and changes the resistance value according to the engine coolant temperature.
The structure of the sensor and connection to the ECM is the same as the Intake Air Temperature (IAT) sensor.
HINT: If the ECM detects the DTC P0115, P0117 or P0118, it operates the fail-safe function in which the ECT is assumed to be 80°C (176°F).
HINT: After confirming DTC "P0115, P0117 or P0118", use the Techstream to confirm the engine coolant temperature in the "Powertrain / Engine and ECT / Data List / All Data / Coolant Temp".
MONITOR DESCRIPTION
The Engine Coolant Temperature (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:
When the ECM calculates that the ECT is -40°C (-40°F) (P0118) or more than 140°C (284°F) (P0117) and if either condition continues for 0.5 seconds or more, the ECM will set a DTC.
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. 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 the Techstream to the DLC3.
(b) Turn the ignition switch ON and turn the tester ON.
(c) Enter the following menus: Powertrain / Engine and ECT / Data List / All Data / Coolant Temp.
(d) Read the values.
Standard:
Same value as the actual ECT.
Result:
HINT:
- If there is an open circuit, the tester indicates -40°C (-40°F).
- If there is a short circuit, the tester indicates 140°C (284°F) or more.
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 E2 Engine Coolant Temperature (ECT) sensor connector.
(b) Connect terminals 1 and 2 of the ECT sensor wire harness side connector.
(c) Connect the Techstream to the DLC3.
(d) Turn the ignition switch ON and turn the tester ON.
(e) Enter the following menus: Powertrain / Engine and ECT / Data List / All Data / Coolant Temp.
(f) Read the value.
Standard:
140°C (284°F) or more
(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 VALUE USING TECHSTREAM (CHECK FOR OPEN IN ECM)
(a) Disconnect the E2 ECT sensor connector.
(b) Connect terminals THW and E2 of the E5 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 ON and turn the tester ON.
(e) Enter the following menus: Powertrain / Engine and ECT / Data List / All Data / Coolant Temp.
(f) Read the value.
Standard:
140°C (284°F) or more
(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 VALUE USING TECHSTREAM (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 ON and turn the tester ON.
(d) Enter the following menus: Powertrain / Engine and ECT / Data List / All Data / Coolant Temp.
(e) Read the value.
Standard:
-40°C (-40°F)
(f) Reconnect the ECT sensor connector.
OK -- REPLACE ENGINE COOLANT TEMPERATURE SENSOR
NG -- Continue to next step.
5. READ VALUE USING TECHSTREAM (CHECK FOR SHORT IN ECM)
(a) Disconnect the E2 ECT sensor connector.
(b) Disconnect the E5 ECM connector.
(c) Connect the Techstream to the DLC3.
(d) Turn the ignition switch ON and turn the tester ON.
(e) Enter the following menus: Powertrain / Engine and ECT / Data List / All Data / Coolant Temp.
(f) Read the value.
Standard:
-40°C (-40°F)
(g) Reconnect the ECT sensor connector.
(h) Reconnect the ECM connector.
NG -- REPLACE ECM
OK -- REPAIR OR REPLACE HARNESS OR CONNECTOR