P0116 ENGINE COOLANT TEMPERATURE (ECT) SENSOR RATIONALITY
When Monitored and Set Condition:
When Monitored: While the engine is running.
Set Condition: The ECM does not read a change in value from the sensor over time.
POSSIBLE CAUSES
- LOW COOLANT LEVEL
- COOLANT TEMPERATURE SENSOR
- THERMOSTAT
- INTERMITTENT CONDITION
DIAGNOSTIC PROCEDURE
NOTE: Refer to VERIFICATION TESTS for appropriate verification test procedures.
-
With the engine cold, verify the level of coolant in the radiator. Is the radiator full of coolant?
Yes --> Go To 2
No --> Fill the radiator with coolant- refer to the owners manual for assistance. Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). -
Remove the temperature sensor and reconnect the wiring to the sensor. Turn the ignition on. Monitor DRBIII®, while heating the sensor with an external heat source (DO NOT USE OPEN FLAME). Does the reading from the sensor increase at least 5 degrees F. on the DRBIII®?
Yes --> Go To 3
No --> Replace the coolant temp sensor. Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). NOTE: Refer to the Symptom: *FUEL HEATER THERMOSTAT TEST to ensure the thermostat is operating properly. -
Is the thermostat operating properly?
Yes --> Refer to the SYMPTOM: INTERMITTENT CONDITION Symptom (Diagnostic Procedure). Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL).
No --> Replace the Thermostat. Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL).