Engine Control System - SFI System (from 12/2010)

2GR-FE ENGINE CONTROL SYSTEM: SFI SYSTEM: P0116: Engine Coolant Temperature Circuit Range / Performance Problem
P0116 - Engine Coolant Temperature Circuit Range / Performance Problem

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.





MONITOR DESCRIPTION

Engine Coolant Temperature Sensor Cold Start Monitor

The monitor runs when the engine is started cold. If the change in engine coolant temperature sensor output until the engine is warmed up completely is less than the threshold, it is determined that a malfunction has occurred in the engine coolant temperature sensor. When this is detected in 2 consecutive driving cycles, the MIL is illuminated and the DTC is stored.

Engine Coolant Temperature Sensor Soak Monitor

When more than 5 hours have elapsed since the engine was stopped, the ECM compares the engine coolant temperature from the time the warmed-up engine is stopped with the engine coolant temperature when the engine is started on the next trip. If the change in engine coolant temperature sensor output is less than the threshold, it is determined that a malfunction has occurred in the engine coolant temperature sensor. When this is detected in 2 consecutive driving cycles, the MIL is illuminated and the DTC is stored.

MONITOR STRATEGY





TYPICAL ENABLING CONDITIONS

All:





ECT sensor cold start monitor:





ECT sensor soak monitor:





TYPICAL MALFUNCTION THRESHOLDS

ECT sensor cold start monitor:





ECT sensor soak monitor:





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. Enter the following menus: Powertrain / Engine / Data List / All Data / Coolant Temp.

4. Check that the engine coolant temperature is 60°C (140°F) or less.

5. Clear the DTCs (even if no DTCs are stored, perform the clear DTC procedure) DTC Check / Clear (from 12/2010).

6. Turn the ignition switch off and wait for 30 seconds.

7. Turn the ignition switch to ON and turn the Techstream on [A].

8. Start the engine and idle it for 5 minutes or more [B].

HINT
If the engine coolant temperature does not change by 5°C (9°F) or higher, the engine coolant temperature sensor is malfunctioning. It is not necessary to continue this procedure.

9. Enter the following menus: Powertrain / Engine / Trouble Codes / Pending.

10. Read the pending DTCs [C].

11. If a pending DTC is output, the system is malfunctioning.

HINT
If a pending DTC is not output, perform the following procedure.

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

13. Input the DTC: P0116.

14. Check the DTC judgment result.





CAUTION:
When performing the confirmation driving pattern, obey all speed limits and traffic laws.

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 steps [D] and [E].

15. Drive the vehicle at 25 mph (40 km/h) or more for a total of 5 minutes or more [D].

HINT
In the event of the drive pattern being interrupted (possibly due to factors such as traffic conditions), the drive pattern can be resumed.

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

17. Check the DTC judgment result again [E].

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

18. 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 (from 12/2010).

HINT
* If a permanent DTC is output, the system is malfunctioning.
* If no permanent DTC is output, the system is normal.

INSPECTION PROCEDURE

HINT
* If any of DTCs P0115, P0117, P0118 and P0125 are set simultaneously with DTC P0116, the ECT sensor may have an open or a short circuit. Troubleshoot those DTCs first.
* 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 Freeze Frame Data.

PROCEDURE

1. CHECK OTHER DTC OUTPUT (IN ADDITION TO DTC P0116)

(a) Connect Techstream to the DLC3.

(b) Turn the ignition switch to ON.

(c) Turn the Techstream on.

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

(e) Read the DTCs.

Result:





HINT
If any DTCs other than P0116 are output, troubleshoot those DTCs first.

B -- GO TO DTC CHART Diagnostic Trouble Code Chart (from 12/2010)
A -- Continue to next step.

2. INSPECT THERMOSTAT

(a) Remove the thermostat Removal.

(b) Check the valve opening temperature of the thermostat.

Standard:

80 to 84°C (176 to 183°F)

HINT
In addition to the above check, confirm that the valve is completely closed when the temperature is below the standard.

(c) Reinstall the thermostat Installation.

NG -- REPLACE THERMOSTAT Removal

OK -- REPLACE ENGINE COOLANT TEMPERATURE SENSOR