Diagnostic Test

WARNING: This page is about a different car, the 2017 RAM 2500 HD. However, it is still accessible from the selected car via links, so may be relevant.

ENGINE COOLANT LEVEL AND CONDITION
WARNING:
Make sure the engine cooling system is cool before removing the pressure cap or any hose. The cooling system is pressurized when hot. Failure to follow these instructions can result in personal injury including extreme burns, scalding, or fatal injury.
1. Check the engine coolant level and the condition of the engine coolant. Refer to the appropriate service information in ENGINE COOLING SYSTEM - 2500 HD .
  Were any problems found?
  
  Yes
  - Repair as necessary in accordance with the service information.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to 5.7L - POWERTRAIN VERIFICATION TEST or 5.7L CNG - POWERTRAIN VERIFICATION TEST or 6.4L - POWERTRAIN VERIFICATION TEST .
  No
  - Go To 2
ECT SENSOR - COLD
NOTE:
The thermostat must be operating correctly for this test to be valid.
1. With the scan tool, read and note the engine coolant temperature.
2. Using a temperature probe, measure the engine block temperature near the ECT Sensor.
  NOTE:
  The engine temperature should be below 50°C (120°F).
  
  Are the readings within 7°C (13°F) of each other?
  
  Yes
  - Go To 3
  No
  - Check the wiring and connectors associated with the ECT Sensor for corrosion, damage or other problems. Repair as necessary. If no problems are found, replace the Engine Coolant Temperature Sensor.
  - Perform the PCM VERIFICATION TEST. Refer to 5.7L - POWERTRAIN VERIFICATION TEST or 5.7L CNG - POWERTRAIN VERIFICATION TEST or 6.4L - POWERTRAIN VERIFICATION TEST .
ECT SENSOR - HOT
NOTE:
The thermostat must be operating correctly for this test to be valid.
1. Start the engine and bring the engine to operating temperature (thermostat open).
2. Turn the engine off and wait 10 minutes to allow the engine temperature to stabilize.
3. Using a temperature probe, measure the engine block temperature near the ECT Sensor.
4. With the scan tool, select Engine, then Sensors and read the engine coolant temperature.
  Are the readings within 7°C (13°F) of each other?
  
  Yes
  - Test Complete.
  No
  - Check the wiring and connectors associated with the ECT Sensor for corrosion, damage or other problems. Repair as necessary. If no problems are found, replace the Engine Coolant Temperature Sensor.
  - Perform the PCM VERIFICATION TEST. Refer to 5.7L - POWERTRAIN VERIFICATION TEST or 5.7L CNG - POWERTRAIN VERIFICATION TEST or 6.4L - POWERTRAIN VERIFICATION TEST .