Radiator Fan High Speed Circuit Troubleshooting
Radiator Fan High Speed Circuit Troubleshooting
1. Check the No. A3-6 (30 A) fuse, the No. A12 (15 A) fuse, and the No. A4 (7.5 A) fuse in the under-hood fuse/relay box, and the No. B16 (7.5 A) fuse in the driver's under-dash fuse/relay box.
Are the fuse(s) OK?
YES -
Reinstall the fuse(s), then go to step 2.
NO -
Replace the fuse(s) and recheck. If the fuse continues to blow, locate and repair the short in the circuit between the under-hood fuse/relay box and the PCM, the under-hood fuse/relay box and the radiator fan motor, the under-hood fuse/relay box and the A/C condenser fan motor, and driver's under-dash fuse/relay box connector terminal F29 and under-hood fuse/relay box connector terminal B12.�
2. Disconnect and remove the relay circuit board and the A/C condenser fan relay from the under-hood fuse/relay box, and test it Testing and Inspection.
Are the relay circuit board and/or the A/C condenser fan relay OK?
YES -
Go to step 3.
NO -
Replace the relay circuit board and/or the A/C condenser fan relay.�
3. Measure the voltage between under-hood fuse/relay box connector terminal D4 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 under-hood fuse/relay box connector terminals D1 and D4 with a jumper wire.
Does the radiator fan run at high speed?
YES -
Go to step 8.
NO -
Go to step 5.
5. Disconnect the radiator fan motor 2P connector, then test the fan motor Testing and Inspection.
Is the fan motor OK?
YES -
Go to step 6.
NO -
Replace the radiator fan motor, and retest.
6. Check for continuity between radiator fan motor 2P connector terminal No. 2 and body ground.
Is there continuity?
YES -
Go to step 7.
NO -
Repair an open in the wire between radiator fan motor 2P connector terminal No. 2 and body ground G301.�
7. Check for continuity between under-hood fuse/relay box connector terminal D1 and radiator fan motor 2P connector terminal No. 1.
Is there continuity?
YES -
Check for poor connections or loose terminals at the under-hood fuse/relay box and the radiator fan motor, the radiator fan motor and body ground G301.�
NO -
Repair an open in the wire between under-hood fuse/relay box connector terminal D1 and radiator fan motor 2P connector terminal No. 1.�
8. Turn the ignition switch to ON (II).
9. Measure the voltage between under-hood fuse/relay box connector terminal B12 and body ground.
Is there battery voltage?
YES -
Go to step 10.
NO -
Repair an open in the wire between driver's under-dash fuse/relay box connector terminal F29 and under-hood fuse/relay box connector terminal B12.�
10. Measure the voltage between under-hood fuse/relay box connector terminal B13 and body ground.
Is there battery voltage?
YES -
Go to step 11.
NO -
Check the PGM-FI sub relay. If the relay is OK, replace the under-hood fuse/relay box.�
11. Turn the ignition switch to LOCK (0).
12. Connect the HDS to the DLC.
13. Turn the ignition switch to ON (II).
14. Make sure the HDS communicates with the vehicle and the PCM. If it does not communicate, troubleshoot the DLC circuit Testing and Inspection.
15. 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.
16. Disconnect PCM connector A (49P).
17. Check for continuity between PCM connector terminal A5 and under-hood fuse/relay box connector terminal D5.
Is there continuity?
YES -
Update the PCM if it does not have the latest software PCM Update, or substitute a known-good PCM, then recheck. If the symptom/indication goes away with a known-good PCM, replace the original PCM Service and Repair.�
NO -
Repair an open the wire between under-hood fuse/relay box connector terminal D5 and PCM connector terminal A5.�