Diagnostic Test

CHECK FOR AN ACTIVE CONDITION
1. Turn the ignition off.
2. Allow the vehicle to sit with the ignition off in an environment where the temperature is consistent and above -64°C (-83°F) until the engine coolant temperature is equal, or close to the environmental ambient temperature.
3. Turn the ignition on.
4. With the scan tool, compare the CAC Temperature reading to the other temperature sensor values.
  Is the CAC Coolant Temperature Sensor value within 40°C (72°F) of the other temperature sensor values?
  
  Yes
  - Perform the INTERMITTENT CONDITION diagnostic procedure. Refer to INTERMITTENT CONDITION .
  No
  - Go To 2
CHECK FOR HIGH RESISTANCE IN THE (K222) CAC COOLANT TEMP SIGNAL CIRCUIT
1. Turn the ignition off.
2. Disconnect the CAC Coolant Temperature Sensor harness connector.
3. Disconnect the PCM C2 harness connector.
4. Measure the resistance of the (K222) CAC Coolant Temp Signal circuit between the CAC Coolant Temperature Sensor harness connector and the PCM C1 harness connector.
  Is the resistance below 3.0 Ohms?
  
  Yes
  - Go To 3
  No
  - Repair the (K222) CAC Coolant Temp Signal circuit for an open or high resistance.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to PRE-DIAGNOSTIC TROUBLESHOOTING PROCEDURE .
CHECK FOR HIGH RESISTANCE IN THE (K901) SENSOR GROUND CIRCUIT
1. Measure the resistance of the (K901) Sensor Ground circuit between the CAC Coolant Temperature Sensor harness connector and the PCM C1 harness connector.
  Is the resistance below 3.0 Ohms?
  
  Yes
  - Go To 4
  No
  - Repair the (K901) Sensor Ground circuit for an open or high resistance.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to PRE-DIAGNOSTIC TROUBLESHOOTING PROCEDURE .
REPLACE THE CAC COOLANT TEMPERATURE SENSOR AND RETEST FOR DTC
1. Replace the CAC Coolant Temperature Sensor in accordance with the Service Information.
2. Connect the CAC Coolant Temperature Sensor and PCM harness connectors.
3. Turn the ignition on.
4. With the scan tool, erase DTCs.
5. Using the recorded Freeze Frame and the When Monitored conditions, operate the vehicle in the conditions that set the DTC.
6. With the scan tool, read DTCs.
  Did the DTC return?
  
  Yes
  - Go To 5
  No
  - Replacing the CAC Coolant Temperature Sensor repaired the fault.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to PRE-DIAGNOSTIC TROUBLESHOOTING PROCEDURE .
CHECK RELATED PCM AND COMPONENT CONNECTIONS
1. Perform any Service Bulletins that apply.
2. Disconnect all PCM harness connectors.
3. Disconnect all related in-line harness connections (if equipped).
4. Disconnect the related component harness connectors.
5. 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.
6. Reconnect all PCM harness connectors. Be certain that all harness connectors are fully seated and the connector locks are fully engaged.
7. Reconnect all in-line harness connectors (if equipped). Be certain that all connectors are fully seated and the connector locks are fully engaged.
8. Reconnect all related component harness connectors. Be certain that all connectors are fully seated and the connector locks are fully engaged.
9. With the scan tool, erase DTCs.
10. Test drive or operate the vehicle in accordance with the when monitored and set conditions.
11. With the scan tool, read DTCs.
  Did the DTC return?
  
  Yes
  - Replace 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 PRE-DIAGNOSTIC TROUBLESHOOTING PROCEDURE .
  No
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to PRE-DIAGNOSTIC TROUBLESHOOTING PROCEDURE .
  - Test complete.