P0116
DTC P0116 ENGINE COOLANT TEMPERATURE CIRCUIT RANGE/PERFORMANCEComponent Location:
COMPONENT LOCATION
GENERAL DESCRIPTION
The Engine Coolant Temperature(ECT) Sensor measures the temperature of engine coolant. The Engine Coolant Temperature (ECT) Sensor is located in 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 Powertrain Control Module (PCM). The PCM applies 5 volts to the ECT sensor. The PCM 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 PCM will receive a high voltage input, and when the engine is warm the PCM will receive a low voltage input. The signal from ECT sensor is used for Injection, ignition timing, idle speed and cooling fan control.
DTC DESCRIPTION
If the change of engine coolant temperature detected by ECT sensor is out of threshold, the PCM determines that a fault exists and a DTC is stored.
DTC Detecting Condition:
Schematic Diagram:
Signal Waveform & Data:
MONITOR SCANTOOL DATA
1. Engine "ON"
2. Monitor Engine Coolant Temperature Sensor parameter on Current data.
3. After the engine has been starting, Check that ECT rises steady to about 90 °C (194 °F) and ECT stabilizes when the thermostat opens.
Specification: ECT rises steady to about 90 °C (194 °F) and ECT stabilizes when the thermostat opens. (Error range is 2 - 3%)
4. Is Current data displayed correctly?
YES: Fault is intermittent caused by poor contact in the sensor's and/or PCM's connector or was repaired and PCM memory was not cleared. 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.
NO: Go to "Component Inspection" procedure.
TERMINAL & CONNECTOR INSPECTION
1. 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.
2. Thoroughly check connectors for looseness, poor connection, bending, corrosion, contamination, deterioration, or damage.
3. Has a problem been found?
YES: Repair as necessary and go to "Verification of Vehicle Repair" procedure.
NO: Go to "Component Inspection" procedure.
COMPONENT INSPECTION
1. Check ECTS
1. Ignition "OFF"
2. Disconnect ECTS connector.
3. Measure resistance between terminals 1 and 3 of the ECT sensor (to ECT sensor side).
Specification: Error range is 2 - 3%
4. Is the measured resistance within specifications?
YES: Go to "Check PCM" as below.
NO: Substitute with a known - good IATS and check for proper operation.
If the problem is corrected, replace IATS and go to "Verification of Vehicle Repair" procedure.
2. Check PCM
1. Ignition "OFF"
2. Connect Scantool and Ignition "ON"
3. Select simulation function on scantool.
4. Simulate voltage at terminal 1 of ECT sensor signal connector.
5. Does the signal value of ECT sensor changes according to simulation voltage?
YES: 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.
NO: Substitute with a known - good PCM and check for proper operation.
If the problem is corrected, replace PCM and go to "Verification of Vehicle Repair" procedure.
VERIFICATION OF VEHICLE REPAIR
After a repair, it is essential to verify that the fault has been corrected.
1. Monitor and record the Freeze Frame Data for the Diagnostic Trouble Code(DTC) which has been diagnosed.
2. Using a Scantool, Clear the DTCs.
3. Operate the vehicle within conditions noted in the freeze frame data or enable conditions.
4. Monitor that all readiness tests have been verified as "Complete"
5. Are any DTCs present?
YES: Go to the applicable troubleshooting procedure.
NO: System is performing to specification at this time.