Diagnostic Test

WARNING: This page is about a different car, the 2019 RAM 3500 HD and 2019 RAM 2500 HD. However, it is still accessible from the selected car via links, so may be relevant.

CHECK FOR AN ENGINE COOLING SYSTEM FAILURE
NOTE:
If any other cooling system DTCs are present, repair those DTCs before proceeding.
1. Check the engine cooling system operation. Refer to DIAGNOSIS AND TESTING .
  Is the Cooling System operating normally?
  
  Yes
  - Go To 2
  No
  - Repair the Cooling System failure.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
CHECK THE ENGINE COOLANT TEMPERATURE (ECT) SENSOR
1. Start the engine.
2. Allow the engine to reach normal operating temperature.
3. Use a temperature probe and measure the engine temperature near the ECT Sensor.
4. With the scan tool, read the ECT Sensor value.
5. Compare the temperature probe reading with the scan tool reading.
  Are the readings within 5.5°C (10°F) of each other?
  
  Yes
  - Repair the cause of mechanical failure.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
  No
  - Replace the Engine Coolant Temperature (ECT) Sensor in accordance with the Service Information.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .