Diagnostic Test

CHECK FOR ANY SERVICE BULLETINS OR PCM SOFTWARE UPDATES
1. Check for any applicable Service Bulletins or Flash updates related to the DTC.
  Are there any applicable Service Bulletins or Flash updates?
  
  Yes
  - Perform the applicable repair.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
  No
  - Go To 2
READ AND RECORD DTCS AND ENVIRONMENTAL DATA AND CHECK FOR OTHER DTCS
1. With the scan tool, read DTCs in all Electronic Control Units (ECUs) and record on the repair order.
2. For future reference, with the scan tool, run and save a vehicle Scan Report and all related recorded data.
3. Refer to the recorded DTCs.
Are there any Engine Coolant Temperature (ECT) Sensor DTCs present?

Yes
- Perform the applicable PCM diagnostic procedure(s). Refer to DTC INDEX (1 OF 2) and/or DTC INDEX (2 OF 2) .
No
- Go To 3
CHECK THE COOLING SYSTEM FOR PROPER LEVEL AND CONDITION
WARNING:
Never open the cooling system when the engine is hot. The system is under pressure. Extreme burns or scalding may result. Failure to follow these instructions can result in possible serious or fatal injury. Allow the engine to cool before opening the cooling system.
1. Inspect the cooling system for proper level and condition in accordance with the Service Information.
  Is the coolant at a proper level and condition?
  
  Yes
  - Go To 4
  No
  - Inspect the cooling system for leaks, perform the appropriate repair(s) and correct the coolant level. Refer to ENGINE COOLING, DIAGNOSIS AND TESTING .
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
CHECK THE THERMOSTAT FOR PROPER OPERATION
NOTE:
Depending on starting temperature, this diagnostic code will only set if the coolant temperature stays below 10°C (50°F) for up to 10 minutes of engine running.
1. Turn the ignition on.
2. With the scan tool, read the Engine Coolant Temperature degree value. If the engine was allowed to sit overnight (cold soak), the temperature value should be close to ambient temperature.
3. Start the engine and with the scan tool, monitor the Engine Coolant Temperature degree value.
4. During engine warm-up with a properly operating thermostat, there should be no coolant flow through the radiator below the temperature of 195°F (90°C). Check the temperature of the inlet and outlet hoses of the radiator. If the thermostat is working properly there should be no temperature indicated at the upper radiator hose until the engine reaches 195°F (90°C). If there is no air flow across the radiator, and both the inlet and outlet hoses seem to increase in temperature below 195°F (90°C) indicates a partially open or stuck open thermostat.
  Does the thermostat open at the proper temperature?
  
  Yes
  - Go To 5
  No
  - Replace the thermostat in accordance with the Service Information. Refer to THERMOSTAT, REMOVAL AND INSTALLATION .
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
CHECK THE ECT SENSOR FOR PROPER OPERATION
1. With the scan tool, read the Engine Coolant Temperature degree value while using a digital thermometer near the ECT Sensor.
  Was the digital thermometer reading relatively close to the scan tool reading for the ECT Sensor?
  
  Yes
  - Go To 6
  No
  - Replace the Engine Coolant Temperature (ECT) Sensor in accordance with the Service Information. Refer to ENGINE SENSORS, REMOVAL AND INSTALLATION .
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
CHECK RELATED PCM AND COMPONENT CONNECTIONS
1. Disconnect all PCM harness connectors.
2. Disconnect all related in-line harness connections (if equipped).
3. Disconnect the related component harness connectors.
4. Inspect harness connectors, component connectors, and all male and female terminals for the following conditions:
  - Proper connector installation.
  - Damaged connector locks.
  - Corrosion.
  - Other signs of water intrusion.
  - Weather seal damage (if equipped).
  - Bent terminals.
  - Overheating due to a poor connection (terminal may be discolored due to excessive current draw).
  - Terminals that have been pushed back into the connector cavity.
  - Check for spread terminals and verify proper terminal tension.
  Repair any conditions that are found.
5. Connect all PCM harness connectors. Be certain that all harness connectors are fully seated and the connector locks are fully engaged.
6. Connect all in-line harness connectors (if equipped). Be certain that all connectors are fully seated and the connector locks are fully engaged.
7. Connect all related component harness connectors. Be certain that all connectors are fully seated and the connector locks are fully engaged.
8. With the scan tool, erase DTCs.
9. Test drive or operate the vehicle in accordance with the when monitored and set conditions.
10. With the scan tool, read DTCs.
  Did the DTC return?
  
  Yes
  - Replace and program the Powertrain Control Module (PCM) in accordance with the Service Information. Refer to MODULE, POWERTRAIN CONTROL (PCM), REMOVAL AND INSTALLATION .
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
  No
  - The wiring or poor connection problem has been repaired.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .