Diagnostic Test

CHECK FOR AN ACTIVE DTC
1. With the scan tool, read HVAC DTCs and record on the repair order.
2. Record the Environmental Data.
3. With the scan tool, erase DTCs.
4. Using the recorded Environmental Data, along with the When Monitored and Set Conditions above, operate the vehicle in the conditions that set the DTC.
5. With the scan tool, read HVAC DTCs.
  Did the DTC return?
  
  Yes
  - Go To 2
  No
  - Perform the INTERMITTENT CONDITIONS TEST. Refer to TESTING FOR AN INTERMITTENT CONDITION .
CHECK THE IN-CAR TEMPERATURE SENSOR FOR PROPER CONNECTION
1. Turn the ignition to the off position.
2. Check the connector to In-Car Temperature Sensor for proper connection and the terminals for damage or corrosion.
  Is the In-Car Temperature Sensor connector properly connected and terminals undamaged or corroded?
  
  Yes
  - Go To 3
  No
  - Repair connector and terminals as necessary.
  - Perform the HVAC VERIFICATION TEST. Refer to HVAC VERIFICATION TEST .
CHECK THE (C36) IN-CAR TEMPERATURE SENSOR SIGNAL CIRCUIT FOR A SHORT TO VOLTAGE
1. Turn the ignition off.
2. Disconnect the HVAC Module C2 harness connector.
3. Disconnect the (C36) In-Car Temperature Sensor harness connector.
4. Turn the ignition on.
5. Measure the voltage of the (C36) In-Car Temperature Sensor Signal circuit.
  Is there any voltage present?
  
  Yes
  - Repair the (C36) In-Car Temperature Sensor Signal circuit for a short to voltage.
  - Perform the HVAC VERIFICATION TEST. Refer to HVAC VERIFICATION TEST .
  No
  - Go To 4
CHECK THE (C36) IN-CAR TEMPERATURE SENSOR SIGNAL CIRCUIT FOR AN OPEN
1. Turn the ignition off.
2. Measure the resistance of the (C36) In-Car Temperature Sensor Signal circuit between the HVAC Module C2 harness connector and the In-Car Temperature Sensor harness connector.
  Is the resistance above 3.0 Ohm?
  
  Yes
  - Repair the (C36) In-Car Temperature Sensor Signal circuit for an open or high resistance.
  - Perform the HVAC VERIFICATION TEST. Refer to HVAC VERIFICATION TEST .
  No
  - Go To 5
CHECK THE IN-CAR TEMPERATURE SENSOR FOR PROPER OPERATION
1. Remove the In-Car Temperature Sensor.
2. Measure the resistance of the In-Car Temperature Sensor and compare the resistance to the In-Car Temperature Sensor Resistance Chart in the Service Information.
  Is the In-Car Temperature Sensor within the specified limits of In-Car Temperature Sensor Resistance Chart?
  
  Yes
  - Go To 6
  No
  - Replace the In-Car Temperature Sensor in accordance to the Service Information.
  - Perform the HVAC VERIFICATION TEST. Refer to HVAC VERIFICATION TEST .
CHECK RELATED HARNESS CONNECTIONS
1. Disconnect all HVAC Module 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.
  - Perform a terminal drag test on each connector terminal to verify proper terminal tension.
  Repair any conditions that are found.
5. Reconnect all HVAC Module harness connectors. Be certain that all harness connectors are fully seated and the connector locks are fully engaged.
6. Reconnect all in-line harness connectors (if equipped). Be certain that all connectors are fully seated and the connector locks are fully engaged.
7. Reconnect 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. Using the recorded Environmental Data, along with the When Monitored and Set Conditions above, operate the vehicle in the conditions that set the DTC.
10. With the scan tool, read HVAC Module DTCs.
  Did the DTC return?
  
  Yes
  - Replace the HVAC Module in accordance with the Service information. Refer to MODULE, HVAC, REMOVAL AND INSTALLATION .
  - Perform the HVAC MODULE VERIFICATION TEST. Refer to STANDARD PROCEDURE .
  No
  - Repair any faulty connections.
  - Perform the HVAC MODULE VERIFICATION TEST. Refer to STANDARD PROCEDURE .