P1114
P1114Component Location:
General Description
The Engine Coolant Temperature Sensor (ECTS) is located in the engine coolant passage of the cylinder head for detecting the engine coolant temperature. The ECTS uses a thermistor whose resistance changes with the temperature. The electrical resistance of the ECTS decreases as the temperature increases, and increases as the temperature decreases. The reference 5 V in the ECM is supplied to the ECTS via a resistor in the ECM. That is, the resistor in the ECM and the thermistor in the ECTS are connected in series. When the resistance value of the thermistor in the ECTS changes according to the engine coolant temperature, the output voltage also changes. During cold engine operation the ECM increases the fuel injection duration and controls the ignition timing using the information of engine coolant temperature to avoid engine stalling and improve drivability.
DTC Description
Checking output signals from ECTS under detecting condition, if an output signal is intermittently below 0.1 V, PCM sets P1114.
DTC Detecting Condition:
Specification:
Signal Waveform:
Schematic Diagram:
Monitor DTC Status
1. Check DTC Status
1. Connect scantool to Data Link Connector(DLC).
2. IG "ON".
3. Select "Diagnostic Trouble Codes(DTCs)" mode, and then Press F5(INFO) to check DTC's information from the DTCs menu
4. Read "DTC Status" parameter.
5. Is parameter displayed "Present fault"?
YES
a. Go to "Terminal and Connector inspection" procedure.
NO
a. 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, ending, corrosion, contamination, deterioration, or damage. Repair or replace as necessary and go to "Verification of Vehicle Repair" procedure.
Terminal and Connector Inspection
1. Many malfunctions in the electrical system are caused by poor harness and terminal condition. 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 "Signal Circuit Inspection" procedure.
Signal Circuit Inspection
1. Check voltage
1. IG "OFF" and disconnect ECTS connector.
2. IG "ON" and ENG "OFF"
3. Measure voltage between terminal 3 of ECTS harness connector and chassis ground.
Specification : Approx. 5 V
4. Is the measured voltage within specification ?
YES - Go to "Component Inspection" procedure.
NO - Go to "Check short to ground in harness" as follows.
2. Check short to ground in harness
1. IG "OFF" and disconnect ECTS connector and PCM connector.
2. Measure resistance between terminal 3 of ECTS harness connector and chassis ground.
3. Measure resistance between terminals 1 and 3 of ECTS harness connector.
Specification : Infinite
4. Is the measured resistance within specification?
YES - Go to "Component Inspection" procedure.
NO - Repair short to ground in harness, and go to "Verification of Vehicle Repair" procedure.
Component Inspection
1. Check ECTS
1. IG "OFF" and disconnect ECTS connector.
2. Measure resistance between terminals 1 and 3 of ECTS connector.(Component side)
Specification :
3. Is the measured resistance within specification?
YES - Go to "Check PCM" as follows.
NO - 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.
2. Check PCM
1. IG "OFF" and connect scantool.
2. Connect probe to terminal 3 of ECTS harness connector.
3. IG "ON" and ENG "OFF" and simulation Function on scantool.
4. Simulate voltage at terminal 3 of ECTS harness connector.
5. Does the signal value of ECT sensor change 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.
CAUTION: There is a memory reset function on scantool that can erase optional components automatically detected and memorized by PCM. Before or after testing PCM on the vehicle, use this function to reuse the PCM.
Verification of Vehicle Repair
After a repair, it is essential to verify that the fault has been corrected.
1. Connect scan tool and select "Diagnostic Trouble Codes(DTCs)" mode
2. Press F5(INFO) and confirm that "DTC Readiness Flag" indicates "Complete". If not, drive the vehicle within conditions noted in the freeze frame data or enable conditions
3. Read "DTC Status" parameter
4. Is parameter displayed "History(Not Present) fault"?
YES - System performing to specification at this time. Clear the DTC
NO - Go to the applicable troubleshooting procedure.