1A
DTC P0116: Engine Coolant Temperature Circuit Range / Performance
Wiring Diagram
1. ECT sensor 2. ECM 3. To other sensors
DTC Detecting Condition and Trouble Area
DTC detecting condition Trouble area
ECT sensor values is less than 20 °C (68 °F) while engine is running more than specified engine load (more than 1000 rpm) for 2 to 1112 min (depending on ECT at engine start) continuously from engine start.
(2 driving cycle detecting logic)
ECT sensor
ECT sensor circuit
Thermostat
ECM
DTC Confirmation Procedure
WARNING:
When performing a road test, select a place where there is no traffic or possibility of a traffic accident and very careful during testing to avoid occurrence of an accident.
Road test should be carried out with 2 persons, a driver and tester, on a level road.
NOTE:
Check to make sure that the following conditions are satisfied when using this “DTC Confirmation Procedure”.
Intake air temperature at engine start: –10 °C (14 °F) to 80 °C (176 °F)
Intake air temperature: –10 °C (14 °F) to 70 °C (158 °F)
Altitude (barometric pressure): 2400 m, 8000 ft or less (560 mmHg, 75 kPa or more)
1) With ignition switch turned OFF, connect scan tool.
2) Turn ON ignition switch, clear DTC.
3) Start engine.
4) Drive vehicle at 40 mph (60 km/h) or higher for 20 min. or more.
5) Stop vehicle.
6) Check DTC and pending DTC.
DTC Troubleshooting
Step Action YES NO
1
Was “Engine and Emission Control System Check” performed?
Go to Step 2.
2
DTC check
1) Connect scan tool with ignition switch turned OFF.
2) Turn ON ignition switch and check DTC displayed on scan tool.
Is DTC P0118 indicated?
Go to Step 3.
3
Engine coolant temp. check
1) With ignition switch turned OFF, install scan tool to DLC.
2) Turn ON ignition switch and check engine coolant temp. displayed on scan tool.
3) Warm up engine to normal operating temp. and check engine coolant temp. displayed on scan tool.
Does engine coolant temp. vary higher than 1 °C (33.8 °F) and rise higher than 70 °C (158 °F)?
Intermittent trouble. Check for intermittent referring to Intermittent and Poor Connection Inspection .
Go to Step 4.
4
Thermostat check
Is there a symptom due to thermostat remaining open (it takes a long time before vehicle heater becomes effective or before engine is warmed to normal operating temp., etc.)?
Check thermostat referring to Thermostat Inspection:M13A .
Go to Step 5.
5
Wire harness check
1) Disconnect ECT sensor connector with ignition switch turned OFF.
2) Check for proper connection to ECT sensor connector at “BLK/BLU” and “GRN/BLK” wire terminals.
3) If OK, then with ignition switch ON.
Is voltage applied to “GRN/BLK” wire terminal about 4 – 6 V?
Go to Step 9.
Go to Step 6.
6
ECM voltage check
1) Turn OFF ignition switch.
2) Check for proper connection of ECM connector at “E119-16” terminal.
3) If OK, then turn ON ignition switch, measure voltage between “E119-16” terminal of ECM connector and body ground.
Is voltage about 4 – 6 V?
Open wire in “GRN/BLK” circuit. If wire and connection are OK, go to Step 7.
Go to Step 7.
7
Wire circuit check
1) Disconnect connectors from ECM with ignition switch turned OFF.
2) Turn ignition switch to ON position.
3) Measure voltage between “GRN/BLK” wire terminal of ECT sensor connector and body ground.
Is voltage about 0 V?
Go to Step 8.
“GRN/BLK” wire shorted to other circuits.
If wire are OK, substitute a known-good ECM and recheck.
8
Wire circuit check
1) Measure resistance between “E119-16” terminal of ECM connector and “GRN/BLK” wire terminal of ECT sensor connector with ignition switch turned OFF.
Is resistance below 5 Ω?
Go to Step 9.
High resistance wire in “GRN/BLK” circuit.
9
Ground circuit check
1) Connect connectors to ECM.
2) Check for proper connection of ECT sensor connector at “BLK/BLU” wire terminal.
3) Measure resistance between “BLK/BLU” wire terminal of ECT sensor connector and body ground.
Is resistance below 5 Ω?
Go to Step 11.
Go to Step 10.
10
Ground circuit check
1) Measure resistance between “E119-28” terminal of ECM connector and body ground.
Is resistance below 5 Ω?
High resistance wire in “BLK/BLU” circuit. Poor “E119-28” connection.
Faulty ECM ground circuit. If circuit are OK, substitute a known-good ECM and recheck.
11
ECT sensor check
1) Check ECT sensor according to Engine Coolant Temperature (ECT) Sensor Inspection:M13A .
Is it in good condition?
Substitute a known-good ECM and recheck.
Replace ECT sensor.
NOTE:
Upon completion of inspection and repair work, perform “DTC Confirmation Procedure” and confirm that the trouble has been corrected.