Component Tests and General Diagnostics
Radiator Fan Circuit Troubleshooting2000-2005 Models
1. Check the No. 57 (20 A), No. 41 (100 A), and No. 42 (40 A) fuses in the main under-hood fuse/relay box, and the No. 20 (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.
2. Remove the radiator fan relay from the main under hood fuse/relay box, and test it.
Is the relay OK?
YES - Go to step 3.
NO - Replace the radiator fan relay.
3. Measure the voltage between the radiator fan relay 4P socket terminal No. 1 and body ground.
Is there battery voltage?
YES - Go to step 4.
NO - Replace the main under-hood fuse/relay box.
4. Connect the radiator fan relay 4P socket terminals No. 1 and No. 2 with a jumper wire.
Does the radiator fan run?
YES - Go to step 5.
NO - Go to step 6.
5. Disconnect the jumper, and turn the ignition switch ON (II). Check for voltage between the radiator fan relay 4P socket terminal No. 3 and body ground.
Is there battery voltage?
YES - Go to step 9.
NO - Repair an open in the wire between the main under-hood fuse/relay box and under-dash fuse/relay box.
6. Disconnect the radiator fan motor 2P connector.
7. Check for continuity between the radiator fan relay 4P socket terminal No. 2 and the radiator fan motor 2P connector terminal No. 2.
Is there continuity?
YES - Go to step 8.
NO - Repair an open in the wire between the main under-hood fuse/relay box and the radiator fan motor 2P connector terminal No. 2.
8. Check for continuity between the radiator fan motor 2P connector terminal No. 1 and body ground.
Is there continuity?
YES - Replace the radiator fan motor.
NO - Repair an open in the wire between radiator fan motor 2P connector terminal No. 1 and body ground. If the wire is OK, check for a poor ground at G201.
9. Reinstall the radiator fan relay.
10. Disconnect the radiator fan switch 2P connector.
11. Turn the ignition switch OFF. Connect the radiator fan switch 2P connector terminals No. 1 and No. 2 with a jumper wire, then turn the ignition switch ON (II).
Does the radiator fan run?
YES - Replace the radiator fan switch.
NO - Go to step 12.
12. Turn the ignition switch OFF. Remove the jumper wire, then turn the ignition switch ON (II). Measure the voltage between the radiator fan switch 2P connector terminal No. 2 and body ground.
Is there battery voltage?
YES - Repair an open in the wire between radiator fan switch 2P connector terminal No. 1 and body ground. If the wire is OK, check for a poor ground at G301.
NO - Repair an open in the wire between the radiator fan switch 2P connector terminal No. 2 and the main under-hood fuse/relay box.
2006 Model
1. Check the No. 57 (20 A), No. 41 (100 A), and No. 42 (40 A) fuses in the main under-hood fuse/relay box, and the No. 20 (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.
2. Remove the radiator fan relay from the main under hood fuse/relay box, and test it.
Is the relay OK?
YES - Go to step 3.
NO - Replace the radiator fan relay.
3. Measure the voltage between the radiator fan relay 4P socket terminal No. 1 and body ground.
Is there battery voltage?
YES - Go to step 4.
NO - Replace the main under-hood fuse/relay box.
4. Connect the radiator fan relay 4P socket terminals No. 1 and No. 2 with a jumper wire.
Does the radiator fan run?
YES - Go to step 5.
NO - Go to step 6.
5. Disconnect the jumper, and turn the ignition switch ON (II). Check for voltage between the radiator fan relay 4P socket terminal No. 3 and body ground.
Is there battery voltage?
YES - Go to step 9.
NO - Repair an open in the wire between the main under-hood fuse/relay box and under-dash fuse/relay box.
6. Disconnect the radiator fan motor 2P connector.
7. Check for continuity between the radiator fan relay 4P socket terminal No. 2 and the radiator fan motor 2P connector terminal No. 2.
Is there continuity?
YES - Go to step 8.
NO - Repair an open in the wire between the main under-hood fuse/relay box and the radiator fan motor 2P connector terminal No. 2.
8. Repair continuity between the radiator fan motor 2P connector terminal No. 1 and body ground.
Is there continuity?
YES - Replace the radiator fan motor.
NO - Repair an open in the wire between radiator fan motor 2P connector terminal No. 1 and body ground. If the wire is OK, check for a poor ground at G201.
9. Reinstall the radiator fan relay.
10. Check for the PGM-FI DTCs.
Is DTC P2183, P2184, and/or P2185 indicated?
YES - Do the appropriate troubleshooting, then recheck.
NO - Go to step 11.
11. Check for continuity between the radiator fan relay 4P socket terminal No. 4 and the ECM connector terminal E12.
Is there continuity?
YES - Update the ECM if it does not have the latest software, or substitute a known-good ECM, then recheck. If the symptom/indication goes away with a known good ECM, replace the original ECM.
NO - Repair an open in the wire between the ECM connector terminal E12 and the main under-hood fuse/relay box.