Radiator Fan High Speed Circuit Troubleshooting
Radiator Fan High Speed Circuit Troubleshooting
NOTE:
- Do not use this troubleshooting procedure if the A/C compressor is inoperative. Refer to the symptom troubleshooting index.
- Before performing symptom troubleshooting, check for powertrain DTCs.
1. Check the No. 30 (30 A) fuse, and the No. 10 (7.5 A) fuse in the under-dash fuse/relay box.
Are the fuses OK?
YES -
Go to step 2.
NO -
Replace the fuse(s) and recheck. If the fuse(s) blow again, repair the short to ground in the No. 30 (30 A) fuse, and/or the No. 10 (7.5 A) fuse circuits.
2. Remove the radiator fan relay from auxiliary under-hood relay box, and the fan control relay from auxiliary under-hood fuse/relay box, and test them Testing and Inspection.
Are the relays OK?
YES -
Go to step 3.
NO -
Replace the radiator fan relay and/or the fan control relay.
3. Check the radiator fan motor Testing and Inspection.
Is the fan motor OK?
YES -
Go to step 4.
NO -
Replace the radiator fan motor Radiator And A/C Condenser Fan, Motor, And Shroud Removal And Installation.
4. Measure the voltage between radiator fan relay 4P socket terminal No. 1 and body ground.
Is there battery voltage?
YES -
Go to step 5.
NO -
Repair an open in the wire between radiator fan relay 4P socket terminal No. 1 and the under-dash fuse/relay box.
5. Turn the ignition switch to ON (II).
6. Measure the voltage between radiator fan relay 4P socket terminal No. 4 and body ground.
Is there battery voltage?
YES -
Go to step 7.
NO -
Repair an open in the wire between radiator fan relay 4P socket terminal No. 4 and the under-dash fuse/relay box.
7. Measure the voltage between fan control relay 5P socket terminal No. 5 and body ground.
Is there battery voltage?
YES -
Go to step 8.
NO -
Repair an open in the wire between fan control relay 5P socket terminal No.5 and the auxiliary under-hood relay box.
8. Turn the ignition switch to LOCK (0).
9. Disconnect the radiator fan motor 2P connector.
10. Check for continuity between radiator fan relay 4P socket terminal No. 2 and radiator fan motor 2P connector terminal No. 2.
Is there continuity?
YES -
Go to the step 11.
NO -
Repair an open in the wire between radiator fan relay 4P socket terminal No. 2 and radiator fan motor 2P connector terminal No. 2.
11. Check for continuity between fan control relay 5P socket terminal No. 1 and radiator fan motor 2P connector terminal No. 1.
Is there continuity?
YES -
Go to the step 12.
NO -
Repair an open in the wire between fan control relay 5P socket terminal No. 1 and radiator fan motor 2P connector terminal No. 1.
12. Check for continuity between fan control relay 5P socket terminal No. 2 and body ground.
Is there continuity?
YES -
Go to the step 13.
NO -
Repair an open in the wire between fan control relay 5P socket terminal No. 2 and body ground G401.
13. Connect the HDS to the DLC.
14. Turn the ignition switch to ON (II).
15. Make sure the HDS communicates with the vehicle and the PCM. If it does not communicate, troubleshoot the DLC circuit DLC Circuit Troubleshooting (PGM-FI System).
16. Jump the SCS line with the HDS, then turn the ignition switch to LOCK (0).
NOTE: This step must be done to protect the PCM from damage.
17. Disconnect PCM connector A (49P).
18. Check for continuity between radiator fan relay 4P socket terminal No. 3 and PCM connector terminal No. A44.
Is there continuity?
YES -
Go to the step 19.
NO -
Repair an open in the wire between radiator fan relay 4P socket terminal No. 3 and PCM connector terminal No. A44.
19. Check for continuity between fan control relay 5P socket terminal No. 3 and PCM connector terminal No. A45.
Is there continuity?
YES -
Update the PCM PCM Update if it does not have the latest software, or substitute a know-good PCM, then recheck. If the symptom goes away with a know-good PCM, replace the original PCM Service and Repair.
NO -
Repair an open in the wire between fan control relay 5P socket terminal No. 3 and PCM connector terminal No. A45.