Scheme 1
Symptom Troubleshooting Index
| Symptom | Diagnostic Procedure | Also check for |
|---|---|---|
| Engine overheats | Check the coolant level. Check for any engine coolant leakage (from gaskets, hoses, O-rings, etc.). Check for dirt, leaves, or insects on radiator and condenser. Check for deteriorated coolant. Check for a damaged or deformed fan shroud. Inspect the fan motors (see FAN MOTOR TEST ) or fan relays (see POWER RELAY TEST ). Check the radiator cap (see RADIATOR CAP TEST ). Check the thermostat (see FAN MOTOR TEST ). Inspect the water pump (see WATER PUMP INSPECTION ). Check for a plugged or deteriorated radiator hoses. Check for plugged heater core or hoses. Check for a damaged cylinder head gasket. | |
| The radiator fan runs at low speed, but it does not run at high speed when the engine coolant temperature is above 199°F (93°C). | RADIATOR FAN HIGH SPEED CIRCUIT TROUBLESHOOTING . | Cleanliness and tightness of all connectors |
| With the A/C off and the engine coolant temperature at 199°F (93°C) or below, the A/C condenser fan runs at high speed and the radiator fan does not run. When the engine coolant temperature is above 199°F (93°C), both fans run at high speed. | Remove the fan control relay, and test. If the relay is faulty, replace it. If the relay is OK, check for a short in the wire between fan control relay 5P socket terminal No. 1 and condenser fan motor 2P connector terminal No. 1. | Cleanliness and tightness of all connectors |
| The radiator fan and the A/C condenser fan run at high speed with the ignition switch ON (II), the A/C off, and the engine coolant temperature below 194°F (90°C) | Check for a short in the wire between radiator fan relay 4P socket terminal No. 3 and PCM connector terminal A5. | Cleanliness and tightness of all connectors |
| Both the radiator fan and the A/C condenser fan run at low speed with the ignition switch ON (II) and the A/C off | Check for a short in the wire between A/C condenser fan relay 4P socket terminal No. 4 and PCM connector terminal A4. | Cleanliness and tightness of all connectors |
| Both the radiator fan and the A/C condenser fan do not run at low speed with the A/C on | Radiator and A/C condenser fans low speed circuit troubleshooting (see RADIATOR AND A/C CONDENSER FAN LOW SPEED CIRCUIT TROUBLESHOOTING ). | Cleanliness and tightness of all connectors |
| The A/C condenser fan does not run at all. The radiator fan does not run at low speed, but it runs at high speed | A/C condenser fans high speed circuit troubleshooting (see A/C CONDENSER FAN HIGH SPEED CIRCUIT TROUBLESHOOTING ). | Cleanliness and tightness of all connectors |
| Both the radiator fan and the A/C condenser fan do not run at high speed when the engine coolant temperature is above 199°F (93°C) | Check for an open in the wire between radiator fan relay 4P socket terminal No. 3 and PCM connector terminal A5. | Cleanliness and tightness of all connectors |
TROUBLESHOOTING CHART
Scheme 2
Scheme 3
Scheme 4
Scheme 5
- Check the No. 6 (30 A) fuse in the under-hood fuse/relay box, and the No. 15 (7.5 A) fuse in the under-hood 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 under-hood fuse/relay box and test it (see «POWER RELAY TEST»(/acura/rdx/i-2006-2009/remont/body-electrical/#relays__power-relay-test) ). Is the relay OK? YES - Go to step 3. NO - Replace the radiator fan relay.
- Measure the voltage between radiator fan relay 4P, socket terminal No. 1 and body ground. Is there battery voltage? YES - Go to step 4. NO - Replace the under-hood fuse/relay box.
- Connect radiator fan relay 4P socket terminals No. 1 and No. 2 with a jumper wire. Does the radiator fan run at high speed? YES - Go to step 5. NO - Repair open in the wire between radiator fan relay 4P socket terminal No. 2 and radiator fan motor 2P connector terminal No. 2.
- Turn the ignition switch ON (II).
- Measure the voltage between radiator fan relay 4P socket terminal No. 4 and body ground. Is there battery voltage? YES - Repair open in the wire between radiator fan relay 4P socket terminal No. 3 and the powertrain control module (PCM) (A5). NO - Check the A/C diode B in the under-hood fuse/ relay box. If the diode is OK, replace the under-hood fuse/relay box.