Heating System Symptom Troubleshooting

NOTE: Before performing symptom troubleshooting, check for DTCs.

Symptom | Diagnostic procedure | Also check for
--- | --- | ---
Recirculation control doors do not change between Fresh and Recirculate | Recirculation control motor circuit troubleshooting | HVAC DTCs Blown fuse No. 30 (7.5 A) in the under-dash fuse/relay box Cleanliness and tightness of all connectors
Both heater and A/C do not work | Audio-HVAC module power and ground circuits troubleshooting | HVAC DTCs Blown fuse No. 30 (7.5 A) in the under-dash fuse/relay box Poor ground at G503 Cleanliness and tightness of all connectors