P0117
Engine Coolant Temperature Sensor Circuit:
CIRCUIT OPERATION
- 5-volt voltage is applied to the engine coolant temperature sensor output terminal (terminal 1) from the ECM (terminal 83)
- 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
DTC SET CONDITIONS
Check Conditions
- 2 seconds or more have passed since the staring sequence was completed.
Judgement Criteria
- Engine coolant temperature sensor output voltage has continued to be 0.1 volt or lower [corresponding to a coolant temperature of 140 °C (284 °F) or higher] for 2 seconds.
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 loose connector
- ECM failed.
- PCM failed.
DIAGNOSIS
Required Special Tools
- MB991502: Scan Tool (MUT-II)
STEP 1. Using scan tool MB991502, check data list item 21: Engine Coolant Temperature Sensor.
CAUTION: To prevent damage to scan tool MB991502, always turn the ignition switch to the "LOCK" (OFF) position before connecting or disconnecting scan tool MB991502.
1. Connect scan tool MB991502 to the data link connector.
2. Turn the ignition switch to the "ON" position.
3. Set scan tool MB991502 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. Refer to How to Use Troubleshooting/Inspection Service Points.
NO: Go to Step 2.
STEP 2. Check connector B-107 at the engine coolant temperature sensor for damage.
Q: Is the connector in good condition?
YES: Go to Step 3.
NO: Repair or replace it. Refer to Harness Connector Inspection. 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-115
Q: Is the harness wire in good condition?
YES: Go to Step 4.
NO: Repair it. Then go to Step 6.
STEP 4. Check connector C-115 at ECM
Q: Is the connector in good condition?
YES: Go to Step 5.
NO: Repair or replace it. Refer to Harness Connector Inspection. 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 °C (-4 °F)]
5.1 - 6.5 kohm [at 0 °C (32 °F)]
2.1 - 2.7 kohm [at 20 °C (68 °F)]
0.9 - 1.3 kohm [at 40 °C (104 °F)]
0.48 - 0.68 kohm [at 60 °C (140 °F)]
0.26 - 0.36 kohm [at 80 °C (176 °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, Procedure 6 - Other Monitor.
2. Check the diagnostic trouble code (DTC).
Q: Is the DTC P0117 output?
YES: Retry the troubleshooting.
NO: The inspection is complete.