Radiator Fan Circuit Troubleshooting
- Check the No. 10 (30 A) fuse in the under-hood fuse/relay box, 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 f use(s) and recheck.
- Remove the radiator fan relay from the main under-hood fuse/relay box, and test it (see
POWER RELAY TEST
).
Is the relay OK?
YES -Go to step 3.
NO -Replace the radiator fan relay.
- Measure the voltage between the radiator fan relay 4P socket terminal No. 2 and body ground.
Is there battery voltage?
YES -Go to step 4.
NO -Replace the main under-hood fuse/relay box.
- 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 8.
NO -Go to step 5.
- Disconnect the radiator fan motor 2P connector.
- Check for continuity between the radiator fan relay 4P socket terminal No. 1 and the radiator fan motor 2P connector terminal No. 2.Fig 3: Checking Continuity Between Radiator Fan Relay 4P Socket Terminal No. 1 And Radiator Fan Motor 2P Connector Terminal No. 2
Is there continuity?
YES -Go to step 7.
NO -Repair open in the wire between the under-hood fuse/relay box and the radiator fan motor 2P connector terminal No. 2.
- 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 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 G301.
- Disconnect the jumper, and turn the ignition switch ON (II). Check for voltage between the radiator fan relay 4P socket terminal No. 4 and body ground.
Is there battery voltage?
YES -Go to step 9.
NO -Repair open in the wire between the under-hood fuse/relay box and under-dash fuse/relay box.
- Check for continuity between the radiator fan relay 4P socket terminal No. 3 and the ECM/PCM connector terminal E12.Fig 6: Checking Continuity Between Radiator Fan Relay 4P Socket Terminal No. 3 And ECM/PCM Connector Terminal E12
Is there continuity?
YES -Update the ECM/PCM if it does not have the latest software (see UPDATING THE ECM/PCM ), or substitute a known-good ECM/PCM (see SUBSTITUTING THE ECM/PCM ), then recheck. If the symptom goes away with a known good ECM/PCM, replace the original ECM/PCM (see ECM/PCM REPLACEMENT ).
NO -Repair open in the wire between the ECM/PCM connector terminal E12 and the under-hood fuse/relay box.