Diagnostic Test

CHECK FOR AN ACTIVE DTC
1. With the scan tool, read 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 HVACR Module DTCs.
  Did the DTC return?
  
  Yes
  - Go To 2
  No
  - Perform the TESTING FOR AN INTERMITTENT CONDITION procedure. Refer to TESTING FOR AN INTERMITTENT CONDITION .
CHECK THE (C257) REAR BLOWER SUPPLY CIRCUIT FOR A SHORT TO GROUND
1. Turn the ignition off.
2. Disconnect the HVACR Module harness connector.
3. Disconnect the Rear Blower Motor Power Module harness connector.
4. Check for continuity between ground and the (C257) Rear Blower Supply circuit at the Rear Blower Motor Power Module harness connector.
  Is there continuity between ground and the (C257) Rear Blower Supply circuit?
  
  Yes
  - Repair the (C257) Rear Blower Supply circuit for a short to ground.
  - Perform the HVAC VERIFICATION TEST. Refer to HVAC VERIFICATION TEST .
  No
  - Go To 3
CHECK THE (C256) REAR BLOWER RETURN CIRCUIT FOR A SHORT TO GROUND
1. Check for continuity between ground and the (C256) Rear Blower Return circuit at the Rear Blower Motor Power Module harness connector.
  Is there continuity between ground and the (C256) Rear Blower Return circuit?
  
  Yes
  - Repair the (C256) Rear Blower Return circuit for a short to ground.
  - Perform the HVAC VERIFICATION TEST. Refer to HVAC VERIFICATION TEST .
  No
  - Go To 4
REPLACE THE REAR BLOWER MOTOR POWER MODULE AND CHECK FOR THE DTC TO RETURN
1. Turn the ignition off.
2. Replace the Rear Blower Motor Power Module in accordance with the Service Information. Refer to MODULE, POWER, REAR BLOWER MOTOR, REMOVAL AND INSTALLATION .
3. Operate the Rear Blower in the conditions that set the DTC. Used the When Monitored and Setting Conditions as an additional guide.
  Did this DTC return?
  
  Yes
  - Go To 5
  No
  - Replacing the Rear Blower Motor Power Module corrected the condition.
  - Perform the HVAC VERIFICATION TEST. Refer to HVAC VERIFICATION TEST .
CHECK RELATED HARNESS CONNECTIONS
1. Disconnect all HVACR 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 HVACR 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 HVACR Module DTCs.
  Did the DTC return?
  
  Yes
  - Replace the HVACR Module in accordance with the Service information. Refer to MODULE, HVAC, REMOVAL AND INSTALLATION .
  - 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 .