Climate Control System Symptom Troubleshooting

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
Blower, heater controls, and A/C do not work | Climate control power and ground circuits troubleshooting | HVAC DTCs Blown fuse No. 30 (7.5 A) in the under-dash fuse/relay box Poor ground at G506 Cleanliness and tightness of all connectors
Both fans do not run at low speed with the A/C on (but the A/C compressor runs with the A/C on) | Radiator and A/C condenser fan low speed circuit troubleshooting | HVAC DTCs Blown fuse No. 9 (20 A) in the under-hood fuse/relay box, and No. 30 (7.5 A) in the under-dash fuse/relay box Poor ground at G301 Cleanliness and tightness of all connectors
The A/C condenser fan does not run at high speed (but both fans run at low speed and the A/C compressor operates with the A/C on) | A/C condenser fan high speed circuit troubleshooting | HVAC DTCs Blown fuse No. 30 (7.5 A) in the under-dash fuse/relay box Poor ground at G302 Cleanliness and tightness of all connectors
The A/C compressor clutch does not engage (but both fans run with the A/C on) | A/C compressor clutch circuit troubleshooting | HVAC DTCs Blown fuse No. 9 (20 A) in the under-hood fuse/relay box, and No. 30 (7.5 A) in the under-dash fuse/relay box Cleanliness and tightness of all connectors
Heating normally doesn't work | Magnet valve circuit troubleshooting | HVAC DTCs Blown fuse No. 30 (7.5 A) in the under-dash fuse/relay box Cleanliness and tightness of all connectors
Blower fan runs slower than expected in cold weather | ECT Troubleshooting NOTE: It is normal for the blower to run slowly until the engine coolant temperature begins to rise. If the blower continues to run slowly for an abnormal length of time, continue to troubleshoot the problem. | Powertrain DTCs