P0117
DTC P0117: Engine Coolant Temperature Circuit Low InputEngine Coolant Temperature Sensor Circuit:
CIRCUIT OPERATION
- 5-volt voltage is applied to the engine coolant temperature sensor output terminal (terminal No. 1) from the ECM
- 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 resistor decreases.
- The engine coolant temperature sensor output voltage increases when the resistor increases and decreases when the resistor decreases.
TECHNICAL DESCRIPTION
- The engine coolant temperature sensor converts the engine coolant temperature to a voltage and output it.
- The ECM
DESCRIPTIONS OF MONITOR METHODS
- A short circuit is detected while monitoring the engine coolant temperature sensor output.
MONITOR EXECUTION
- Continuous
MONITOR EXECUTION CONDITIONS (Other monitor and Sensor)
Other Monitor (There is no temporary DTC stored 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:
Logic Flow Chart
Check Condition
- 2 seconds or more have passed since the starting sequence was completed.
Judgement Criterion
- Engine coolant temperature sensor output voltage has continued to be 0.1 volt or lower [corresponding to a coolant temperature of 140 degrees C (284 degrees F) or higher] for 2 seconds.
OBD-II DRIVE CYCLE PATTERN
Refer to Diagnostic Function - OBD-II Drive Cycle - Pattern 21 OBD-II Drive Cycle Pattern Lists.
TROUBLESHOOTING HINTS (The most likely causes for this code to be set are: )
- Engine coolant temperature sensor failed.
- Open or shorted engine coolant temperature sensor circuit, or connector damage.
- ECM failed.
- PCM failed.
DIAGNOSIS
Required Special Tools:
- MB991958: Scan Tool (MUT-III Sub Assembly)
- MB991824: V.C.I.
- MB991827: USB Cable
- MB991911: Main Harness B
STEP 1. Using scan tool MB991958, check data list item 21: Engine Coolant Temperature Sensor.
CAUTION: To prevent damage to scan tool MB991958, always turn the ignition switch to the "LOCK" (OFF) position before connecting or disconnecting scan tool MB991958.
1. Connect scan tool MB991958 to the data link connector.
2. Turn the ignition switch to the "ON" position.
3. Set scan tool MB991958 to the data reading mode for item 21, Engine Coolant Temperature Sensor.
- The engine coolant temperature and temperature shown with the scan tool should approximately match.
4. Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the sensor operating properly?
YES: It can be assumed that this malfunction is intermittent.
NO: Go to Step 2.
STEP 2. Check harness connector B-107 at the engine coolant temperature sensor for damage.
Q: Is the harness connector in good condition?
YES: Go to Step 3.
NO: Repair or replace it. Then go to Step 6.
STEP 3. Check for short circuit to ground between engine coolant temperature sensor connector B-107 and ECM connector C-117
Q: Is the harness wire in good condition?
YES: Go to Step 4.
NO: Repair it. Then go to Step 6.
STEP 4. Check harness connector C-117 at ECM
Q: Is the harness connector in good condition?
YES: Go to Step 5.
NO: Repair or replace it. Then go to Step 6.
STEP 5. Check the engine coolant temperature sensor.
1. Disconnect the engine coolant temperature sensor connector B-107.
2. Remove the engine coolant temperature sensor.
3. With the temperature sensing portion of engine coolant temperature sensor immersed in hot water, check resistance.
Standard value:
14 - 17 kohm [at - 20 degree C (- 4 degree F)]
5.1 - 6.5 kohm [at 0 degree C (32 degrees F)]
2.1 - 2.7 kohm [at 20 degrees C (68 degrees F)]
0.9 - 1.3 kohm [at 40 degrees C (104 degrees F)]
0.48 - 0.68 kohm [at 60 degrees C (140 degrees F)]
0.26 - 0.36 kohm [at 80 degrees C (176 degrees F)]
4. Apply 3M(TM) AAD part number 8731 or equivalent on the screw section of the engine coolant temperature sensor.
5. Install the engine coolant temperature sensor, and tighten to the specified torque.
Tightening torque: 29 ± 10 N.m (22 ± 7 ft-lb)
Q: Is the resistance at the standard value?
YES: Replace the ECU or PCM. Then go to Step 6.
NO: Replace the engine coolant temperature sensor. Then go to Step 6.
STEP 6. Test the OBD-II drive cycle.
1. Carry out a test drive with the drive cycle pattern. Refer to Diagnostic Function - OBD-II Drive Cycle - Pattern 21 OBD-II Drive Cycle Pattern Lists.
2. Check the diagnostic trouble code (DTC).
Q: Is DTC P0117 set?
YES: Retry the troubleshooting.
NO: The inspection is complete.