P0117
DTC P0117 ENGINE COOLANT TEMPERATURE CIRCUIT LOW INPUTComponent Location:
GENERAL DESCRIPTION
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 (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
Checking output signals from ECTS every 80 sec. under detecting condition, if an output signal is below 0.1 V for more than 40 sec., PCM sets P0117. MIL (Malfunction Indication Lamp) turns on when the malfunction lasts till consecutive 2 driving cycle.
DTC Detecting Condition:
Specification:
Schematic Diagram:
Signal Waveform And Data:
MONITOR SCANTOOL DATA
1. Connect scantool to Data Link Connector (DLC).
2. IG "ON".
3. Select "Diagnostic Trouble Codes (DTCs)" mode, and then Press F4(DTAL) to check DTC's information from the DTCs menu
4. Read "DTC Status" parameter.
5. Is parameter displayed "Present fault"?
YES: Go to "Component Inspection" procedure.
NO: Fault is intermittent, go to "Verification of vehicle Repair" procedure.
TERMINAL AND 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 "Terminal and connector 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.
NOTE: There is a memory reset function on scantool that can erase optional parts automatically detected and memorized by PCM. Before or after testing PCM on the vehicle, use this function to reuse the PCM on the others.
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 F4(DTAL) 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.