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 (C362) CABIN HEATER 2 RELAY CONTROL CIRCUIT FOR AN OPEN
1. Turn the ignition off.
2. Disconnect the HVAC Module C1 harness connector.
3. Remove the Cabin Heater 2 Relay from the Power Distribution Center (PDC).
4. Turn the ignition on.
5. Measure the resistance of the (C362) Cabin Heater 2 Relay Control circuit between the HVAC Module C1 harness connector and the PDC.
  Is the resistance above 1.0 Ohm?
  
  Yes
  - Repair the open on the (C362) Cabin Heater 2 Relay Control circuit for an open.
  - Perform the HVAC VERIFICATION TEST. Refer to HVAC VERIFICATION TEST .
  No
  - Go To 3
CHECK (C362) CABIN HEATER 2 RELAY CONTROL CIRCUIT FOR SHORT TO BATTERY
1. Turn the ignition off.
2. Disconnect the HVAC Module C1 harness connector.
3. Remove the Cabin Heater 2 Relay.
4. Measure the voltage on the (C362) Cabin Heater 2 Relay Control circuit at the Cabin Heater 2 Relay connector.
  Is there any voltage present?
  
  Yes
  - Repair the (C362) Cabin Heater 2 Relay Control circuit for a short to battery.
  - Perform the HVAC VERIFICATION TEST. Refer to HVAC VERIFICATION TEST .
  No
  - Go To 4
CHECK THE CABIN HEATER 2 RELAY FOR PROPER OPERATION
1. Replace the Cabin Heater 2 Relay with a known good relay.
2. Turn the ignition on.
3. With the scan tool, erase DTCs.
4. With the scan tool, actuate the Cabin Heater 2 Relay.
5. Monitor the scan tool for at least two minutes.
6. With the scan tool, read HVAC DTCs.
  Did the DTC reset?
  
  Yes
  - Go To 5
  No
  - Replace the Cabin Heater Relay 2 in accordance with 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 HVAC VERIFICATION TEST .
  No
  - Repair any faulty connections
  - Perform the HVAC MODULE VERIFICATION TEST. Refer to HVAC VERIFICATION TEST .