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DTC P0117-00: Engine Coolant Temperature Sensor circuit low input
 
 
 
 
CIRCUIT OPERATION
  • A power voltage of 5 volts is applied to the engine coolant temperature sensor connector terminal number 1 from the ECM connector terminal number 38.
  • The power voltage is grounded to the ECM connector terminal number 28 from the engine coolant temperature sensor connector terminal number 2.
  • The engine coolant temperature sensor is a negative temperature coefficient type of resistor. It has the characteristic that when the engine coolant temperature rises the resistance decreases.
  • The engine coolant temperature sensor output voltage increases when the resistance increases and decreases when the resistance decreases.
 
 
TECHNICAL DESCRIPTION
  • The engine coolant temperature sensor converts the engine coolant temperature to a voltage and outputs it.
  • The ECM checks whether this voltage is within a specified range.
 
 
DESCRIPTIONS OF MONITOR METHODS
Engine coolant temperature sensor output voltage is out of specified range.
 
 
MONITOR EXECUTION
Continuous.
 
 
MONITOR EXECUTION CONDITIONS (Other monitor and Sensor)
Other Monitor (There is no temporary DTC set in memory for the item monitored below)
  • Not applicable
Sensor (The sensor below is determined to be normal)
  • Not applicable
 
 
DTC SET CONDITIONS
Logic Flow Chart
Check Condition
  • More than 2 seconds have passed since the power supply mode of the electric motor switch was ON.
    or
  • More than 2 seconds have passed since the key-off evaporative leakage monitoring was started.
Judgment Criterion
  • Engine coolant temperature sensor output voltage has continued to be lower than 0.1 volt for 2 seconds.
 
 
FAIL-SAFE AND BACKUP FUNCTION
Fuel control is carried out by estimating water temperature from intake air temperature.
 
 
OBD-II DRIVE CYCLE PATTERN
Refer to Diagnostic Function, OBD-II Drive Cycle – Pattern 1 OBD- II DRIVE CYCLE.
 
 
TROUBLESHOOTING HINTS (The most likely causes for this code to be set are:)
  • Engine coolant temperature sensor failed.
  • Shorted engine coolant temperature sensor circuit or connector damage.
  • ECM failed.
 
 
DIAGNOSIS
Required Special Tools:
  • MB992744: Vehicle communication interface-Lite (V.C.I.-Lite)
  • MB992745: V.C.I.-Lite main harness A
  • MB992747: V.C.I.-Lite USB cable short
  • MB992748: V.C.I.-Lite USB cable long
1.STEP 1. Using scan tool (M.U.T.-III SE), check the data list.
Use scan tool (M.U.T.-III SE) to check the data list (Refer to DATA LIST REFERENCE TABLE).
  • Item number 60: Coolant (Water) Temperature Sensor
Q: Is the check result normal?
 
2.STEP 2. Check engine coolant temperature sensor itself.
Check engine coolant temperature sensor itself (Refer to ENGINE COOLANT TEMPERATURE SENSOR CHECK).
Q: Is the check result normal?
Replace the engine coolant temperature sensor (Refer to ENGINE, Engine Cooling – Water Hose and Water Pipe WATER HOSE AND WATER PIPE REMOVAL AND INSTALLATION).
 
3.STEP 3. Perform voltage measurement at engine coolant temperature sensor connector terminal number 1.
  • Disconnect connector, and measure at harness side.
  • Power supply mode of electric motor switch: ON
  • Voltage between engine coolant temperature sensor connector terminal number 1 and ground.
OK: 4.9 to 5.1 volts
Q: Is the check result normal?
 
4.STEP 4. Check harness between engine coolant temperature sensor connector terminal number 1 and ECM connector terminal number 38.
Check power supply line for short circuit.
Q: Is the check result normal?
Repair or replace the connector, or repair the damaged harness wire.
 
5.STEP 5. Using scan tool (M.U.T.-III SE), check the data list.
Use scan tool (M.U.T.-III SE) to check the data list (Refer to DATA LIST REFERENCE TABLE).
  • Item number 60: Coolant (Water) Temperature Sensor
Q: Is the check result normal?
Replace the ECM (Refer to ENGINE CONTROL MODULE (ECM) REMOVAL AND INSTALLATION).
 
6.STEP 6. Test the OBD-II drive cycle.
After erasing the DTC, carry out test drive with the drive cycle pattern, and recheck the DTC.
(1) Use scan tool (M.U.T.-III SE) to erase the DTC.
(2) Carry out test drive with the drive cycle pattern (Refer to Diagnostic Function, OBD-II Drive Cycle – Pattern 1 OBD- II DRIVE CYCLE).
(3) Use scan tool (M.U.T.-III SE) to recheck the DTC.
Q: Is DTC P0117-00 set?
Replace the ECM (Refer to ENGINE CONTROL MODULE (ECM) REMOVAL AND INSTALLATION).
Intermittent malfunction (Refer to GENERAL INFORMATION, General Information – How to Use Troubleshooting/Inspection Service Points – How to Cope with Intermittent Malfunctions HOW TO COPE WITH INTERMITTENT MALFUNCTIONS).