Climate Control System Symptom Troubleshooting

NOTE: Before performing symptom troubleshooting, check for body and powertrain DTCs.

Symptom | Diagnostic procedure | Also check for
--- | --- | ---
Recirculation control doors do not change between Fresh and Recirculate | Recirculation control motor circuit troubleshooting | 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 | Climate control power and ground circuits troubleshooting | 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
The A/C condenser fan does not run at all (but radiator fan runs with the A/C on) | A/C condenser fan circuit troubleshooting | 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 G201 Cleanliness and tightness of all connectors
Both fans do not run with the A/C on (but the A/C compressor runs with the A/C on) | Radiator and A/C condenser fans common circuit troubleshooting | DTCs Blown fuse No. 9 (20 A) and No. 4 (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
The A/C compressor clutch does not engage (but both fans run with the A/C on) | A/C compressor clutch circuit troubleshooting | DTCs Blown fuse No. 12 (7.5 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
A/C system does not come on (both fans and the A/C compressor are inoperative) | A/C pressure switch circuit troubleshooting | DTCs Cleanliness and tightness of all connectors
Blower fan runs slower than expected in cold weather | ECT troubleshooting | Powertrain DTCs