A/C Condenser Fan High Speed Circuit Troubleshooting
A/C Condenser Fan High Speed Circuit Troubleshooting
NOTE:
- Do not use this troubleshooting procedure if the A/C compressor is inoperative. Refer to the symptom troubleshooting.
- Before performing symptom troubleshooting, check for powertrain DTCs; R18A1 engine Initial Inspection and Diagnostic Overview, K20Z3 engine Initial Inspection and Diagnostic Overview.
- If A/C refrigerant pressure is abnormal, the radiator fans are controlled based on engine coolant temperature.
1. Check the No. 6 (20 A) and No. 15 (7.5 A) fuses in the under-hood fuse/relay box.
Are the fuses OK?
YES -
Go to step 2.
NO -
Replace the fuse(s), and recheck. If the fuse(s) blows again, check for a short in the No. 6 (20 A) fuse and the No. 15 (7.5 A) fuse circuits.�
2. Remove the A/C condenser fan relay from the under-hood fuse/relay box, and test it Testing and Inspection.
Is the relay OK?
YES -
Go to step 3.
NO -
Replace the A/C condenser fan relay.�
3. Measure the voltage between A/C condenser fan relay 4P socket terminal No. 1 and body ground.
Is there battery voltage?
YES -
Go to step 4.
NO -
Replace the under-hood fuse/relay box Under-Hood Fuse/Relay Box Removal and Installation.�
4. Connect A/C condenser fan relay 4P socket terminals No. 1 and No. 2 with a jumper wire.
Does the A/C condenser fan run on high?
YES -
Go to step 5.
NO -
Replace the under-hood fuse/relay box Under-Hood Fuse/Relay Box Removal and Installation.�
5. Disconnect the jumper wire.
6. Turn the ignition switch to ON (II).
7. Measure the voltage between A/C condenser fan relay 4P socket terminal No. 4 and body ground.
Is there battery voltage?
YES -
Go to step 8.
NO -
Go to step 15.
8. Turn the ignition switch to LOCK (0).
9. Check for continuity between fan control relay 5P socket terminal No. 2 and body ground.
Is there continuity?
YES -
Go to step 10.
NO -
Check for an open in the wire between the fan control relay and body ground. If the wire is OK, check for poor body ground at G301; R18A1 engine, K20Z3 engine.�
10. Reinstall the A/C condenser fan relay.
11. Jump the SCS line with the HDS.
NOTE: This step must be done to protect the ECM/PCM from damage.
12. Disconnect ECM/PCM connector A (44P).
13. Connect ECM/PCM connector A (44P) terminals No. 5 and No. 21 to body ground with jumper wires.
14. Turn the ignition switch to ON (II).
Does the A/C condenser fan run on high?
YES -
Check for loose wires or poor connections at ECM/PCM connector A (44P) terminal No. 5. If the connections are good, substitute a known-good ECM/PCM; R18A1 engine, K20Z3 engine, and recheck. If the symptom/indication goes away, replace the original ECM/PCM; R18A1 engine , K20Z3 engine Service and Repair.�
NO -
Repair an open in the wire between the A/C condenser fan relay and the ECM/PCM.�
15. Turn the ignition switch to LOCK (0).
16. Remove A/C diode B from the under-hood fuse/relay box.
17. Turn the ignition switch to ON (II).
18. Measure the voltage between A/C diode B 2P socket terminal No. 2 and body ground.
Is there battery voltage?
YES -
Go to step 19.
NO -
Replace the under-hood fuse/relay box Under-Hood Fuse/Relay Box Removal and Installation.�
19. Using the diode setting () on a DVOM, check for current flow in both directions between A/C diode B terminals No. 1 and No. 2.
Is there current flow in only one direction?
YES -
Replace the under-hood fuse/relay box Under-Hood Fuse/Relay Box Removal and Installation.�
NO -
Replace A/C diode B.�