Engine Cooling Cooling System Component Location Index... 10-2 Radiator Cap Test... 10-3 Radiator Test... 10-3 Fan Motor Test... 10-4 Thermostat Test... 10-4 Water Pump Inspection... 10-5 Water Pump Replacement... 10-5 Coolant Check... 10-6 Coolant Replacement... 10-6 Thermostat Replacement... 10-8 Water Passage Replacement... 10-9 Radiator and Fan Replacement... 10-12 Fan Controls Component Location Index... 10-15 Symptom Troubleshooting Index... 10-16 Circuit Diagram... 10-17 Radiator Fan High Speed Circuit Troubleshooting... 10-18
Cooling System Component Location Index WTER PUMP Inspection, page 10-5 Replacement, page 10-5 RDITOR CP Test,page 10-3 WTER PSSGE Replacement, page 10-9 RDITOR Replacement, page 10-12 RDITOR FN SSEMLY Replacement, page 10-12 Fan Motor Test, page 10-4 THERMOSTT Test, page 10-4 Replacement, page 10-8 10-2
Radiator Cap Test 1. Remove the radiator cap (). Wet its seal with engine coolant, then install it on a commercially available pressure tester (). Radiator Test 1. Wait until the engine is cool, then carefully remove the radiator cap, and fill the radiator with engine coolant to the top of the filler neck. 2. ttach a commercially available pressure tester () to the radiator, and apply a pressure of 93 123 kpa 2 (0.95 1.25 kgf/cm, 14 18 psi). 2. pply a pressure of 93 123 kpa (0.95 2 1.25 kgf/cm, 14 18 psi). 3. Check for a drop in pressure. 4. If the pressure drops, replace the cap. 3. Inspect for engine coolant leaks and a drop in pressure. 4. Remove the tester, then reinstall the radiator cap. 10-3
Cooling System Fan Motor Test 1. Disconnect the 2P connectors from the radiator fan motor () and condenser fan motor (). Terminal side of male terminals Thermostat Test Replace the thermostat if it is in the stuck open position at room temperature. To test a closed thermostat: 1. Suspend the thermostat () in a container of water. Do not let the thermometer () touch the bottom of the hot container. 2. Test each motor by connecting battery power to the No. 1 terminal and ground to the No. 2 terminal. 3. If either motor fails to run or does not run smoothly, replace it (see page 10-12). 2. Heat the water and check the temperature with a thermometer. Note the temperature at which the thermostat first opens, and at which it is fully open. 3. Measure the lift height of the thermostat when it is fully open. Standard Thermostat Lift Height: bove 10.0 mm (0.39 in.) Starts Opening: 169 176 F (76 80 C) Fully Open: 194 F (90 C) 10-4
Water Pump Inspection 1. Remove the timing belt (see page 6-13). 2. Turn the water pump pulley counterclockwise. Check that it turns freely. If it doesn t turn smoothly, replace the water pump (see page 10-5). NOTE: When you check the water pump, you may see a small amount of weeping from the bleed holes (). This is normal. Water Pump Replacement 1. Drain the engine coolant (see page 10-6). 2. Remove the timing belt (see page 6-13). 3. Remove the timing belt adjuster (see page 6-24). 4. Remove the water pump () by removing the five bolts. 3. Install the timing belt (see page 6-16). 6x1.0mm 12 N m (1.2 kgf m, 8.7 lbf ft) 5. Inspect and clean the O-ring groove and the mating surface of the engine block. 6. Install the water pump with a new O-ring () in the reverse order of removal. 7. Clean up any spilled engine coolant. 8. Install the timing belt adjuster (see page 6-24). 9. Install the timing belt (see page 6-16). 10. Refill the radiator with engine coolant, then bleed the air from the cooling system (see step 9 on page 10-7). 10-5
Cooling System Coolant Check 1. Look at the coolant level in the coolant reservoir. Make sure it is between the MX mark () and MIN mark (). Coolant Replacement 1. Start the engine. Set the heater temperature control dial to maximum heat, then turn off the ignition switch. Make sure the engine and radiator are cool to the touch. 2. Remove the radiator cap. 3. Remove the splash shield (see step 30 on page 5-5). 4. Loosen the drain plug (), and drain the coolant. 2. If the coolant level in the coolant reservoir is at or below the MIN mark, add coolant to bring it between the MIN and MX marks, then inspect the cooling system for leaks. 5. Install a rubber hose () on the drain bolt () located at the rear of the engine block, then loosen the drain bolt. 9.8 N m (1.0 kgf m, 7.2 lbf ft) 6. When the coolant stops draining, tighten the drain bolt. Remove the rubber hose. 7. Tighten the radiator drain plug securely. 8. Install the splash shield (see step 31 on page 5-17). 10-6
9. Remove, drain, and reinstall the reserve tank. 10. Fill the reserve tank to the MX mark () with Honda Long Life ntifreeze/coolant Type 2 (P/N OL999-9001). 12. Install the radiator cap loosely. 13. Start the engine and let it run until it warms up (the radiator fan comes on at least twice). 14. Turn off the engine. Check the level in the radiator and add Honda Long Life ntifreeze/coolant Type 2, if needed. 15. Put the radiator cap on tightly, then run the engine again, and check for leaks. 16. Clean up any spilled engine coolant. 11. Pour Honda Long Life ntifreeze/coolant Type 2 into the radiator up to the base of the filler neck. NOTE: lways use Honda Long Life ntifreeze/coolant Type 2 (P/N OL999-9001). Using a non-honda coolant can result in corrosion, causing the cooling system to malfunction or fail. Honda Long Life ntifreeze/coolant Type 2 is a mixture of 50 % antifreeze and 50 % water. Do not add water. Engine Coolant Capacities (Including the reserve tank capacity of 0.6 L (0.16 US gal)): fter Coolant Change: 6.2 L (1.64 US gal) fter Engine Overhaul: 8.1 L (2.14 US gal) 10-7
Cooling System Thermostat Replacement 1. Disconnect the breather pipe, then remove the air intake duct (see step 9 on page 5-2). 2. Drain the engine coolant (see page 10-6). 3. Remove the ground cable and thermostat cover, then remove the thermostat. PIN THERMOSTT COVER GROUND CLE RUER SEL Replace. THERMOSTT Install with pin up. 6x1.0mm 12 N m (1.2 kgf m, 8.7 lbf ft) 4. Install the new thermostat with a new rubber seal. 5. Refill the radiator with engine coolant, then bleed air from the cooling system (see step 9 on page 10-7). 6. Clean up any spilled engine coolant. 10-8
Water Passage Replacement 1. Drain the engine coolant (see page 10-6). 6. Remove the heater hoses. 2. Remove the intake manifold (see page 9-3). 3. Remove the upper radiator hose () and lower radiator hose (). 4. Remove the water bypass hose () and ground cable (). C 7. Remove the engine wire harness connectors from the water passage. Engine coolant temperature (ECT) sensor 1 connector Engine coolant temperature (ECT) sensor 2 connector Exhaust gas recirculation (EGR) valve connector 8. Remove the water passage () and connecting pipe (). D 5. Remove the harness holder mounting bolt (C), then remove the harness holder (D) from the bracket. (cont d) 10-9
Cooling System Water Passage Replacement (cont d) 9. Remove the EGR valve (), ECT sensor 1 (), ECT sensor 2 (C), thermostat cover (D), and thermostat (E). I H 8x1.25mm 22 N m (2.2 kgf m, 16 lbf ft) 12 N m (1.2 kgf m, 8.7 lbf ft) 13. Install the connecting pipe () and water passage (), using the new O-rings (C) and new gaskets (D). D C G C 12 N m (1.2 kgf m, 8.7 lbf ft) H C E F D 6x1.0mm 12 N m (1.2 kgf m, 8.7 lbf ft) 14. Install the heater hoses. 8x1.25mm 22 N m (2.2 kgf m, 16 lbf ft) 10. Install the new rubber seal (F) onto the thermostat, then install the thermostat with pin (G) up, and install the thermostat cover. 11. Install the ECT sensor 1 and ECT sensor 2, using the new O-rings (H). 12. Install the EGR valve, using a new gasket (I). 10-10
15. Install harness holder () to the bracket, then tighten the mounting bolt (). C D 6x1.0mm 12 N m (1.2 kgf m, 8.7 lbf ft) 6x1.0mm 12 N m (1.2 kgf m, 8.7 lbf ft) 18. Install the intake manifold (see page 9-5). 19. fter installation, check that all tubes, hoses and connectors are installed correctly. 20. Refill the radiator with engine coolant, then bleed air from the cooling system (see step 9 on page 10-7). 21. Clean up any spilled engine coolant. 16. Install the water bypass hose (C) and ground cable (D). 17. Install the upper radiator hose () and lower radiator hose (). 10-11
Cooling System Radiator and Fan Replacement 1. Drain the engine coolant (see page 10-6). 2. Remove the front air intake duct. 4. Disconnect the fan motor connectors (), then remove the harness clamps () and reservoir tank hose (C). C 5. Remove the upper radiator hose () and lower radiator hose (). 3. Remove the bulkhead cover. 10-12
6. Remove the splash shield. 9. Remove the harness clamps () and /C compressor clutch connector () from the /C condenser fan shroud. 7. Remove the automatic transmission fluid (TF) cooler hoses () from the radiator, then plug the line and hose. 8. Unclamp the TF cooler hoses clamp () on the TF cooler line. (cont d) 10-13
Cooling System Radiator and Fan Replacement (cont d) 10. Remove the upper bracket cushions, then pull up the radiator. LOWER RDITOR HOSE UPPER RDITOR HOSE RDITOR CP 6x1.0mm 9.8 N m (1.0 kgf m, 7.2 lbf ft) 6x1.0mm 7.1 N m (0.72 kgf m, 5.2 lbf ft) UPPER RCKET ND CUSHION RESERVE TNK RDITOR FN SHROUD RDITOR RDITOR FN MOTOR 6.0 N m (0.61 kgf m, 4.4 lbf ft) RDITOR FN O-RING Replace. DRIN PLUG LOWER CUSHION 6x1.0mm 7.1 N m (0.72 kgf m, 5.2 lbf ft) /C CONDENSER FN/ SHROUD SSEMLY 11. Remove the fan shroud assemblies and other parts from the radiator. 12. Install the radiator in the reverse order of removal. Make sure the upper and lower cushions are set securely. 13. Fill the radiator with engine coolant, then bleed air from the cooling system (see step 9 on page 10-7). 10-14
Fan Controls Component Location Index UXILIRY UNDER- HOOD RELY OX /C CONDENSER FN RELY Test, page 22-75 RDITOR FN RELY Test, page 22-75 FN CONTROL RELY Test, page 22-75 /C CONDENSER FN SSEMLY Motor Test, page 10-4 ENGINE COOLNT TEMPERTURE (ECT) SENSOR 1 Replacement, page 11-201 RDITOR FN SSEMLY Motor Test, page 10-4 ENGINE COOLNT TEMPERTURE (ECT) SENSOR 2 Replacement, page 11-201 10-15
Fan Controls Symptom Troubleshooting Index Symptom Diagnostic Procedure lso check for Engine overheats 1. Check the coolant level. 2. Check for any engine coolant leaks (from gaskets, hoses, O-rings, etc.). 3. Check for dirt, leaves, or insects on radiator and /C condenser. 4. Check for deteriorated coolant. 5. 6. The radiator fan runs at low speed, but it does not run at high speed when the engine coolant temperature is above 206 F (97 C) With the /C off and the engine coolant temperature at 206 F (97 C) or below, the /C condenser fan runs at high speed and the radiator fan does not run. When the engine coolant temperature is above 206 F (97 C), both fans run at high speed The radiator fan runs at high speed with the ignition switch ON (II), the /C off, and the engine coolant temperature below 204 F (95 C) oth the radiator fan and the /C condenser fan run at low speed with the ignition switch ON (II) and the /C off oth the radiator fan and the /C condenser fan do not run at low speed with the /C on The /C condenser fan does not run at all. The radiator fan does not run at low speed, but it runs at high speed oth the radiator fan and the /C condenser fan do not run at high speed when the engine coolant temperature is above 206 F (97 C) 7. 8. 9. 10. Check for damaged or deformed fan shroud. Inspect the fan motors (see page 10-4) or fan relays (see page 22-75). Check the radiator cap (see page 10-3). Check the thermostat (see page 10-4). Inspect the water pump (see page 10-5). Check for a plugged or deteriorated radiator hoses. Check for plugged heater core or hoses. Check for a damaged cylinder head gasket. 11. 12. Radiator fan high speed circuit troubleshooting (see page 10-18). 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. Check for a short in the wire between radiator fan relay 4P socket terminal No. 3 and PCM connector terminal 5. Check for a short in the wire between /C condenser fan relay 4P socket terminal No. 3 and PCM connector terminal 4. Radiator and /C condenser fans low speed circuit troubleshooting (see page 21-40). /C condenser fans high speed circuit troubleshooting (see page 21-44). Check for an open in the wire between radiator fan relay 4P socket terminal No. 3 and PCM connector terminal 5. Cleanliness and tightness of all connectors Cleanliness and tightness of all connectors Cleanliness and tightness of all connectors Cleanliness and tightness of all connectors Cleanliness and tightness of all connectors Cleanliness and tightness of all connectors Cleanliness and tightness of all connectors 10-16
Circuit Diagram TTERY LK/YEL UNDER HOOD FUSE/RELY OX No.22 (T) (120 ) No.23 (IG) (50 ) G1 WHT IGNITION SWITCH 2 T 4 IG2 D2 No.8 (15 ) No.19 (30 ) No.20 (30 ) E6 D5 WHT/GRN D10 IG2HOTinON(III) YEL 4 YEL YEL/GRN No.23 (7.5 ) PGM FI MIN RELY 1 No.30 (7.5 ) UNDER DSH FUSE/RELY OX D16 YEL/WHT X1 RED/YEL D7 LK/YEL YEL UXILIRY UNDER HOOD RELY OX LK/YEL 1 4 1 5 1 4 2 3 RDITOR FN RELY 4 2 3 FN CONTROL RELY 2 3 /C CONDENSER FN RELY LU/LK GRN LU/LK GRN LU/YEL GRN/YEL LU/LK LK 2 2 G201 GRN 1 WHT/RED /C CONDENSER FN MOTOR 1 RDITOR FN MOTOR PCM 5 FNH 4 FNL 6 MRLY 5V TW SG2 TW2 C27 C14 C36 LK RED/WHT GRN/YEL GRN/RED ENGINE COOLNT TEMPERTURE (ECT) SENSOR 1 ENGINE COOLNT TEMPERTURE (ECT) SENSOR 2 G201 10-17
Fan Controls Radiator Fan High Speed Circuit Troubleshooting 1. Check the No. 19 (30 ) fuse in the under-hood fuse/relay box, and the No. 23 (7.5 ) fuse in the under-dash fuse/relay box. re the f uses OK? 4. Connect radiator fan relay 4P socket terminals No. 1 and No. 2 with a jumper wire. RDITOR FN RELY 4P SOCKET YES Go to step 2. NO Replace the fuse(s) and recheck. JUMPER WIRE 2. Remove the radiator fan relay from the auxiliary under-hood relay box and test it (see page 22-75). 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 the body ground. RDITOR FN RELY 4P SOCKET Terminal side of female terminals Does the radiator fan run at high speed? YES Go to step 5. NO Repair open in the wire between the radiator fan relay 4P socket terminal No. 2 and radiator fan motor 2P connector terminal No. 2. 5. Turn the ignition switch ON (II). 6. Measure voltage between radiator fan relay 4P socket terminal No. 4 and the body ground. RDITOR FN RELY 4P SOCKET Terminal side of female terminals Is there battery voltage? YES Go to step 4. NO Repair open in the wire between radiator fan relay 4P socket terminal No. 1 and the under-hood fuse/relay box. Terminal side of female terminals Is there battery voltage? YES Repair open in the wire between the radiator fan relay 4P socket terminal No. 3 and the powertrain control module (PCM) (5). NO Repair open in the wire between the radiator fan relay 4P socket terminal No. 4 and the underdash fuse/relay box. 10-18