3.
Monitor "ECTS" parameter on scantool.
The Engine Coolant Temperature(ECT) Sensor measures the temperature of engine coolant. The Engine Coolant Temperature (ECT) Sensor is located near the thermostat housing of the cylinder head. ECT Sensor is a thermistor (A Variable Resistor that Changes Along with ECT) in series with a fixed resistor in the Engine Control Module (ECM). The ECM applies 5 volts to the ECT sensor. The ECM monitors the voltage across the ECT sensor and converts it into a temperature reading. When the engine is cold the ECT sensor resistance is high, and when the engine is warm the ECT sensor resistance is low. Therefore, when the engine is cold the ECM will receive a high voltage input, and when the engine is warm the ECM will receive a low voltage input. The signal from ECT sensor is used for Injection control, ignition timing, idle speed and cooling fan control.
ECM compares measured value to model value, then the deviation between 2 values is over the threshold value, ECM sets DTC P0116.
Item | Detecting Condition | Possible Cause |
DTC Strategy | ● Rationality check | ● Poor connection ● ECTS ● ECM |
Enable Conditions | ● Low heat power mode driving counter ≥ 2 ● High heat power mode driving counter ≥ 2 | |
Threshold Value | ● Max temp. - Min temp. 〈 0.8~3.0 ℃ (1.44~5.4 ℉) | |
Diagnostic Time | ||
MIL | ● ON |
Connect scantool to DLC(Data Link Cable).
Warm up the engine to normal operating temperature.
Monitor "ECTS" parameter on scantool.
Is the "ECTS" parameter displayed correctly?
▶ Fault is intermittent caused by poor contact in the sensor’s and/or ECM’s connector or was repaired and ECM memory was not cleared. Thoroughly check connectors for looseness, poorconnection, ending, corrosion, contamination, deterioration, or damage. Repair or replace asnecessary and go to "Verification of Vehicle Repair" procedure.
▶ Go to "Terminal and Connector Inspection" procedure.
Many malfunctions in the electrical system are caused by poor harness and terminals. Faults can also be caused by interference from other electrical systems, and mechanical or chemical damage.
Thoroughly check connectors for looseness, poor connection, bending, corrosion, contamination, deterioration, or damage.
Has a problem been found?
▶ Repair as necessary and go to "Verification of vehicle Repair" procedure.
▶ Go to " Voltage check " procedure.
Check ECTS resistance.
IG "OFF".
Disconnect ECTS connector.
Measure resistance between terminal 1 and 2 of ECTS harness connector.(Component Side)
Temperature [℃] | Temperature [℉] | Resistance [Ω] |
-40.0 | -40.0 | 48.14 |
-20.0 | -4.0 | 14.13 ~ 16.83 |
0.0 | 32.0 | 5.79 |
20.0 | 68.0 | 2.31 ~ 2.59 |
40.0 | 104.0 | 1.15 |
60.0 | 140.0 | 0.59 |
80.0 | 176.0 | 0.32 |
Is the measured resistance within specification?
▶ Go to "Check ECM" as follows.
▶ Substitute with a known - good ECTS and check for proper operation.
▶ If the problem is corrected, replace ECTS and go to "Verification of Vehicle Repair" procedure.
Check ECM.
IG "OFF" and disconnect ECTS connector.
Connect scantool and Key "ON".
Select simulation function on scantool.
Simulate voltage at terminal 1 of ECTS signal connector.
Does the signal value of ECTS change according to simulation voltage?
▶ Thoroughly check connectors for looseness, poor connection, bending, corrosion, contamination, deterioration, or damage. Repair or replace as necessary and go to "Verification of Vehicle Repair" procedure.
▶ Substitute with a known - good ECM and check for proper operation.
▶ If the problem is corrected, replace ECM and go to "Verification of Vehicle Repair" procedure.
After a repair, it is essential to verify that the fault has been corrected.
Connect scan tool and select "Diagnostic Trouble Codes(DTCs)" mode.
Clear the DTCs and Operate the vehicle within DTC Enable conditions in General information.
Are any DTCs present ?
▶ Go to the applicable troubleshooting procedure.
▶ System is performing to specification at this time.
