Diagnostic Test
- CHECK FOR AN ACTIVE DTC
- With the scan tool, read HVAC DTCs and record on the repair order.
- Record the Environmental Data.
- With the scan tool, erase DTCs.
- Using the recorded Environmental Data, along with the When Monitored and Set Conditions above, operate the vehicle in the conditions that set the DTC.
- 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 (C361) CABIN HEATER 1 RELAY CONTROL CIRCUIT FOR SHORT TO GROUND
- Turn the ignition off.
- Disconnect the HVAC Module C1 harness connector.
- Remove the Cabin Heater 1 Relay.
- Check for continuity between ground and the (C361) Cabin Heater 1 Relay Control circuit at the Cabin Heater 1 Relay connector.
Is there continuity between ground and the Cabin Heater 1 Relay Control circuit?
Yes
- Repair the Cabin Heater 1 Relay Control circuit for a short to ground.
- Perform the HVAC VERIFICATION TEST. Refer to HVAC VERIFICATION TEST .
No
- Go To 3
- CHECK THE CABIN HEATER 1 RELAY FOR PROPER OPERATION
- Replace the Cabin Heater 1 Relay with a known good relay.
- Turn the ignition on.
- With the scan tool, erase DTCs.
- With the scan tool, actuate the Cabin Heater 1 Relay.
- Monitor the scan tool for at least two minutes.
- With the scan tool, read HVAC DTCs.
Did the DTC reset?
Yes
- Go To 4
No
- Replace the Cabin Heater Relay 1 in accordance with the Service Information.
- Perform the HVAC VERIFICATION TEST. Refer to HVAC VERIFICATION TEST .
- CHECK RELATED HARNESS CONNECTIONS
- Disconnect all HVAC Module harness connectors.
- Disconnect all related in-line harness connections (if equipped).
- Disconnect the related component harness connectors.
- 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.
- Reconnect all HVAC Module harness connectors. Be certain that all harness connectors are fully seated and the connector locks are fully engaged.
- Reconnect all in-line harness connectors (if equipped). Be certain that all connectors are fully seated and the connector locks are fully engaged.
- Reconnect all related component harness connectors. Be certain that all connectors are fully seated and the connector locks are fully engaged.
- With the scan tool, erase DTCs.
- Using the recorded Environmental Data, along with the When Monitored and Set Conditions above, operate the vehicle in the conditions that set the DTC.
- 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 .