P0118

2GR-FSE ENGINE CONTROL SYSTEM: SFI SYSTEM: P0115, P0117, P0118: Engine Coolant Temperature Circuit Malfunction
P0118 - Engine Coolant Temperature Circuit High Input

DESCRIPTION

A thermistor, whose resistance value varies according to the ECT, is built into the Engine Coolant Temperature (ECT) sensor.

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 is low, the resistance in the thermistor increases. When the temperature is high, 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 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 engine switch on (IG) and turn the Techstream on.

3. Clear the DTCs (even if no DTCs are stored, perform the clear DTC procedure).

4. Turn the engine switch off and wait for 30 seconds.

5. Turn the engine switch on (IG) and turn the Techstream on [A].

6. Wait 0.5 seconds or more.

7. Enter the following menus: Powertrain / Engine / Trouble Codes.

8. Read the DTC [B].

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 / Utility / All Readiness.

10. Input the DTC: P0115, P0117 or P0118.

11. Check the DTC judgment result.

HINT
- If the judgment result shows ABNORMAL, the system has a malfunction.
- If the judgment result shows NORMAL, the system is normal.
- If the judgment result shows INCOMPLETE or UNKNOWN, perform step [A] again.

12. Enter the following menus: Powertrain / Engine / Utility / All Readiness.

13. Check the DTC judgment result.

HINT
- If the judgment result shows ABNORMAL, the system has a malfunction.
- If the judgment result shows NORMAL, the system is normal.

14. If the test result is INCOMPLETE or UNKNOWN and no DTC is output, perform a universal trip and check for permanent DTCs Reading and Clearing Diagnostic Trouble Codes.

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. 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. READ OUTPUT DTC

(a) Connect the Techstream to the DLC3.

(b) Turn the engine switch on (IG) and turn the Techstream on.

(c) Enter the following menus: Powertrain / Engine / Trouble Codes.

(d) Read the DTCs.

Result:

C -- READ VALUE USING TECHSTREAM (CHECK FOR OPEN IN WIRE HARNESS)

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

2. READ VALUE USING TECHSTREAM (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 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).

C -- CHECK FOR INTERMITTENT PROBLEMS

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

3. READ VALUE USING TECHSTREAM (CHECK FOR OPEN IN WIRE HARNESS)

(a) Disconnect the E71 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 engine switch on (IG).

(e) Turn the Techstream on.

(f) Enter the following menus: Powertrain / Engine / Data List / Coolant Temp.

(g) Read the value displayed on the Techstream.

Standard:

140°C (284°F).

(h) Reconnect the ECT sensor connector.

OK -- CONFIRM GOOD CONNECTION TO SENSOR. IF OK, REPLACE ENGINE COOLANT TEMPERATURE SENSOR
NG -- Continue to next step.

4. READ VALUE USING TECHSTREAM (CHECK FOR OPEN IN ECM)

(a) Disconnect the E71 ECT sensor connector.

(b) Connect terminals THW and ETHW of the E6 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 engine switch on (IG).

(e) Turn the Techstream on.

(f) Enter the following menus: Powertrain / Engine / Data List / Coolant Temp.

(g) Read the value displayed on the Techstream.

Standard:

140°C (284°F).

(h) Reconnect the ECT sensor connector.

OK -- REPAIR OR REPLACE HARNESS OR CONNECTOR

NG -- CONFIRM GOOD CONNECTION TO ECM. IF OK, REPLACE ECM

5. READ VALUE USING TECHSTREAM (CHECK FOR SHORT IN WIRE HARNESS)

(a) Disconnect the E71 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. READ VALUE USING TECHSTREAM (CHECK FOR SHORT IN ECM)

(a) Disconnect the E6 ECM 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 ECM connector.

OK -- REPAIR OR REPLACE HARNESS OR CONNECTOR

NG -- REPLACE ECM