Diagnostic Test

1. With the scan tool, read DTCs in all Electronic Control Units (ECUs) and record on the repair order.
2. Record the Environmental Data.
3. With the scan tool, erase all DTCs.
4. Turn the ignition off for a minimum of 10.0 seconds.
5. Turn the ignition on.
6. Using the When Monitored and Set Conditions above and recorded data, operate the vehicle in the conditions that set the DTC.
7. With the scan tool, read DTCs.

   Did the DTC return?

   Yes 

   • Go To  2

   No 

   • The condition or conditions that originally set this DTC are not present at this time. Using the wiring diagrams as a guide, check all related splices and connectors for signs of water intrusion, corrosion, pushed out or bent terminals and correct the pin tension. If no problems are found, test complete.
   • Perform the HVAC VERIFICATION TEST. Refer to HVAC VERIFICATION TEST  .

1. With the scan tool, perform the HVAC Actuator Calibration Test and recheck DTCs.

   Did the DTC return?

   Yes 

   • Go To  3

   No 

   • Go To  5

1. The ignition must be off when performing a resistance check to find a short between circuits.
2. Isolate the circuit by disconnecting the ECU and the component harness connectors containing the circuit being tested. Note  : Use the wiring diagram as a guide to follow the path of the circuit. Check the disconnected connectors and related harnesses for damage, corrosion, and loose fitting terminals.
3. Connect one lead of the Digital Volt-Ohm Meter (DVOM) to the circuit being tested at the ECU harness connector.
4. With the other lead of the DVOM probe all other circuits at the ECU harness connector.
   NOTE:

   When back-probing a circuit at a harness connector, always use an appropriate back probing tool to prevent damage to the connector terminals.

Is there continuity between the circuit being tested and any other circuit?

Yes 

• Repair the circuit for a short to another circuit. Use the wiring diagram as a guide to trace the circuits and look for any in-line connectors to help isolate the location of the short.
• Perform the HVAC VERIFICATION TEST. Refer to HVAC VERIFICATION TEST  .

No 

• Go To  4

1. Replace the Air Recirculation Motor in accordance with the Service Information.
2. Connect the Recirculation Door Actuator, ECU, and any other disconnected harness connectors.
3. Turn the ignition on.
4. With the scan tool, erase DTCs.
5. Using the Environmental Data and When Monitored conditions, operate the vehicle within the conditions that set the DTC.
6. With the scan tool, read DTCs.

   Did the DTC return?

   Yes 

   • Go To  5

   No 

   • Replacing the Air Recirculation Motor corrected the condition.
   • Perform the HVAC VERIFICATION TEST. Refer to HVAC VERIFICATION TEST  .

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 .
    • Perform the HVAC VERIFICATION TEST. Refer to HVAC VERIFICATION TEST  .

    No 

    • The wiring or poor connection problem has been repaired.
    • Perform the HVAC VERIFICATION TEST. Refer to HVAC VERIFICATION TEST  .