P0117
DTC P0117 ENGINE COOLANT TEMPERATURE CIRCUIT LOW INPUTComponent Location:
GENERAL DESCRIPTION
An Engine Coolant Temperature Sensor (ECTS) monitors the temperature of the coolant. This input is used by the PCM for engine control and as an enabling criteria for same diagnostics. The air flow coming into the engine is accumulated and used to determine if the engine has been driven within conditions that would allow the engine coolant to heat up normally to the thermostat regulating temperature. If the coolant temperature does not reach regulating temperature of the thermostat, diagnostics that use engine coolant temperature as enabling criteria, may not run when expected.
This DTC will set when there has been excessive time to reach a minimum coolant temperature required for closed loop fuel control.
DTC DESCRIPTION
PCM sets DTC P0117 if the PCM detects signal voltage lower than the possible range of a properly operating ECTS.
DTC Detecting Condition:
Specification:
Schematic Diagram:
Signal Waveform:
MONITOR DTC STATUS
1. Connect scan tool and select "Diagnostic Trouble Codes(DTCs)" mode.
2. Press F4(DTAL) to select DTC information from the DTCs menu.
3. Confirm that "DTC Readiness Flag" indicates "Complete". If not, drive the vehicle within conditions noted in the freeze frame data or enable conditions.
4. Read "DTC Status" parameter.
5. Is parameter displayed "History(Not Present) fault"?
NOTE:
1. History (Not Present) fault: DTC occurred but has been cleared.
2. Present fault: DTC is occurring at present time.
YES: Fault is intermittent caused by poor contact in the sensor's and/or the PCM's connector, which was repaired but 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 "Cooling system inspection" procedure.
MONITOR SCANTOOL DATA
1. Ignition "ON" & Engine "OFF".
2. Disconnect FCTS connector.
3. Connect Scantool and monitor the "COOLANT TEMP SNSR(V)" parameter on the Scantool data list.
Specification : Approx. 5 V
4. Is ECTS parameter near the specified value?
YES: Possibility of sensor malfunction. Go to "Component Inspection" procedure.
NO: Possibility of signal circuit short to ground. Go to next step as below.
SIGNAL CIRCUIT INSPECTION
1. Ignition "OFF".
2. Measure resistance between terminal 1 of the sensor harness connector and chassis ground.
Specification : Infinite
3. Is resistance within the specification?
YES: Go to "Terminal and Connector Inspection" procedure.
NO: Repair short to ground in harness and go to "Verification of Vehicle Repair" procedure.
TERMINAL & CONNECTOR INSPECTION
1. Many malfunctions in the electrical system are caused by poor harness(es) 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: Check for poor connection between ECM and component: backed out terminal, improper mating, broken locks or poor terminal to wire connection. Repair as necessary and go to "Verification of Vehicle Repair" procedure
COMPONENT INSPECTION
1. Disconnect ECTS connector.
2. Measure resistance between terminals 1 and 3 of the sensor connector(Component side).
Specification:
3. Is resistance within the specification?
YES: Check for poor connection between PCM and component: backed out terminal, improper mating, broken locks or poor terminal to wire connection. Repair as necessary and go to "Verification of Vehicle Repair" procedure.
NO: Check ECTS for contamination, deterioration, or damage. Substitute with a known-good ECTS and check for proper operation. If the problem is corrected, replace ECTS and then go to "Verification of Vehicle Repair" procedure.
VERIFICATION OF VEHICLE REPAIR
After a repair, it is essential to verity 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". It 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.