Diagnostic Test

CHECK FOR ACTIVE DTC
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 .
CHECK THE (C56) BLOWER MOTOR POWER MODULE CONTROL CIRCUIT FOR A SHORT TO GROUND
1. Turn the ignition off.
2. Disconnect the HVAC Module harness connector.
3. Disconnect the Blower Motor Power Module C1 harness connector.
4. Check for continuity between ground and the (C56) Blower Motor Power Module Control circuit.
  Is there continuity between ground and the circuit?
  
  Yes
  - Repair the (C56) Blower Motor Power Module Control circuit for a short to ground.
  - Perform the HVAC VERIFICATION TEST. Refer to HVAC VERIFICATION TEST .
  No
  - Go To 3
REPLACE THE BLOWER MOTOR POWER MODULE AND CHECK FOR THE DTC TO RETURN
1. Replace the Blower Motor Power Module in accordance with the Service Information. Refer to MODULE, POWER, BLOWER MOTOR, REMOVAL .
2. Operate the vehicle in the same conditions that originally set the DTC. Use the When Monitored conditions as an additional guide.
  Did the DTC return?
  
  Yes
  - Go To 4
  No
  - Replacing the Blower Motor Power Module corrected the condition.
  - 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 .
  No
  - The wiring or poor connection problem has been repaired.
  - Perform the HVAC VERIFICATION TEST. Refer to HVAC VERIFICATION TEST .