Radiator Fan High Speed Circuit Troubleshooting
Radiator Fan High Speed Circuit Troubleshooting
1. Check the No. B30 (30 A) fuse and the No. B10 (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 the No. B30 (30 A) fuse, and the No. B10 (7.5 A) fuse circuit.
2. Remove the radiator fan relay from auxiliary under-hood relay box B and the fan control relay from auxiliary under-hood relay box A, and test the 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 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 socket terminal No. 1 and under-dash fuse/relay box connector B (36P) terminal No. 34. If the wire is OK, replace auxiliary under-hood relay box B.
5. Turn the ignition switch to ON (II).
6. Measure the voltage between radiator fan relay socket terminal No. 7 and body ground.
Is there battery voltage?
YES -
Go to step 7.
NO -
Repair an open in the wire between radiator fan relay socket terminal No. 7 and under-dash fuse/relay box connector B (36P) terminal No. 1. Check the A/C diode B. If the wire and A/C diode B is OK, replace auxiliary under-hood relay box B.
7. Measure the voltage between fan control relay socket terminal No. 13 and body ground.
Is there battery voltage?
YES -
Go to step 8.
NO -
Repair an open in the wire between auxiliary under-hood relay box A fan control relay socket terminal No. 13 and auxiliary under-hood relay box B A/C diode B socket terminal No. 13. If the wire is OK, replace auxiliary under-hood relay box A.
8. Turn the ignition switch to LOCK (0).
9. Disconnect the radiator fan motor 2P connector.
10. Check for continuity between radiator fan relay socket terminal No. 2 and radiator fan motor 2P connector terminal No. 1.
Is there continuity?
YES -
Go to the step 11.
NO -
Repair an open in the wire between radiator fan relay socket terminal No. 2 and radiator fan motor 2P connector terminal No. 1.
11. Check for continuity between fan control relay socket terminal No. 6 and radiator fan motor 2P connector terminal No. 2.
Is there continuity?
YES -
Go to the step 12.
NO -
Repair an open in the wire between fan control relay socket terminal No. 6 and radiator fan motor 2P connector terminal No. 2.
12. Check for continuity between fan control relay socket terminal No. 5 and body ground G401.
Is there continuity?
YES -
Go to the step 13.
NO -
Repair an open in the wire between fan control relay socket terminal No. 5 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 ECM/PCM. If it does not communicate, troubleshoot the DLC circuit DLC Circuit Troubleshooting (F-CAN, IMA-CAN, K-LINE).
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 ECM/PCM from damage.
17. Disconnect ECM/PCM connector A (44P).
18. Check for continuity between radiator fan relay socket terminal No. 8 and ECM/PCM connector terminal A4.
Is there continuity?
YES -
Go to the step 19.
NO -
Repair an open in the wire between radiator fan relay socket terminal No. 8 and ECM/PCM connector terminal A4.
19. Check for continuity between fan control relay socket terminal No. 15 and ECM/PCM connector terminal A5.
Is there continuity?
YES -
Update the ECM/PCM ECM/PCM Update if it does not have the latest software, or substitute a known-good ECM/PCM, then recheck. If the symptom goes away with a known-good ECM/PCM, replace the original ECM/PCM Service and Repair.
NO -
Repair an open in the wire between fan control relay socket terminal No. 15 and ECM/PCM connector terminal A5.