P0116

P0116-ENGINE COOLANT TEMPERATURE (ECT) SENSOR RATIONALITY

P0116 - Engine Coolant Temperature (ECT) Sensor Rationality:

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

Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding.

Diagnostic Test

1. LOW COOLANT LEVEL
With the engine cold, verify the level of coolant in the radiator.

Q: Is the radiator full of coolant?

YES: Go To 2
NO: Fill the radiator with coolant- refer to the owners manual for assistance. Perform the POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). Powertrain Verification Test - Ver 1

2. COOLANT TEMPERATURE SENSOR
Remove the temperature sensor and reconnect the wiring to the sensor.
Turn the ignition on.
Monitor scan tool, while heating the sensor with an external heat source (DO NOT USE OPEN FLAME).

Q: Does the reading from the sensor increase at least 5 degrees F. on the scan tool?

YES: Go To 3
NO: Replace the coolant temp sensor. Perform the POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). Powertrain Verification Test - Ver 1

3. THERMOSTAT

NOTE: refer to the no trouble code test "Thermostat Test" to ensure the thermostat is operating properly.

Q: Is the thermostat operating properly?

YES: Refer to the INTERMITTENT CONDITION Symptom (Diagnostic Procedure). Perform the POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). Powertrain Verification Test - Ver 1
NO: Replace the Thermostat. Perform the POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). Powertrain Verification Test - Ver 1