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Engine Cooling
Cooling System
Fan Controls
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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 . 10-8Drive Belt Inspection . 10-10
Drive Belt Replacement . 10-10
Drive Belt Auto-Tensioner Inspection . 10-11
Drive Belt Auto-Tensioner Replacement . 10-12
Radiator and Fan Replacement . 10-13
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Component Location Index . 10-16
Symptom Troubleshooting Index . 10-17
Circuit Diagram . 10-18
Radiator Fan High Speed Circuit Troubleshooting . 10-19
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10-2
Cooling System
Component Location Index
WATER PUMP
ENGINE COOLANT TEMPERATURE(ECT) SENSOR 2
RADIATOR FAN ASSEMBLY
RADIATOR
COOLANT RESERVOIR
THERMOSTAT
WATER PASSAGE
RADIATOR CAP
Inspection, page 10-5Replacement, page 10-5
Replacement, page 10-13Fan Motor Test, page 10-4
Replacement, page 10-13
Test, page 10-4Replacement, page 10-8
Replacement, page 10-8
Test, page 10-3
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10-310-3
Radiator Cap Test Radiator Test
A
B
A
1. Remove the radiator cap (A). Wet its seal with
engine coolant, then install it on a commercially
available pressure tester (B).
2. Apply a pressure of 93 123 kPa
(0.95 1.25 kgf/cm , 14 18 psi).
3. Check for a drop in pressure.
4. If the pressure drops, replace the cap.
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. Attach a commercially available pressure tester (A)
to the radiator, and apply a pressure of 93 123 kPa
(0.95 1.25 kgf/cm , 14 18 psi).
3. Inspect for engine coolant leaks and a drop in
pressure.
4. Remove the tester, and reinstall the radiator cap.
2
2
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Standard Thermostat
Lift Height: Above 8.0 mm (0.31 in.)
Starts Opening: 176 183 F (80 84 C)Fully Open: 203 F (95 C)
10-410-4
Cooling System
Fan Motor Test Thermostat Test
A
B
1. Disconnect the 2P connectors from the radiator and
A/C condenser fan motors.
2. Test each motor by connecting battery power to
terminal No. 2 and ground to terminal No. 1.
3. If a motor fails to run or does not run smoothly,
replace it (see page 10-13).
Replace the thermostat if it is in the stuck open position
at room temperature.
To test a closed thermostat:
1. Suspend the thermostat (A) in a container of water.
Do not let the thermometer (B) touch the bottom of
the hot container.
2. Heat the water, and check the temperature with a
thermometer. Check 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.
Terminal side ofmale terminals
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10-510-5
Water Pump Inspection Water Pump Replacement
A
A
6 x 1.0 mm14 Nm(1.4 kgfm, 10 lbfft)
6 x 1.0 mm12 Nm(1.2 kgfm, 8.7 lbfft)
B
A
1. Remove the engine under cover, then remove the
splash shield (see step 22 on page 5-5).
2. Remove the drive belt (see page 10-10).
3. Remove the auto-tensioner (see page 10-12).
4. Turn the water pump pulley counterclockwise.
Check that it turns freely. If it doesnt 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 (A). This is normal.
5. Install the auto-tensioner (see page 10-12).
6. Install the drive belt (see page 10-10).
7. Install the engine under cover and the splash shield
(see step 42 on page 5-19).
1. Remove the engine under cover, then remove the
splash shield (see step 22 on page 5-5).
2. Remove the drive belt (see page 10-10).
3. Drain the engine coolant (see page 10-6).
4. Remove the water pump pulley mounting bolts.
5. Remove the auto-tensioner (see page 10-12).
6. Remove the five bolts securing the water pump,
then remove the water pump (A) with water pump
pulley.
7. Inspect and clean the O-ring groove and the mating
surface with the engine block.
8. Install the water pump with a new O-ring (B) in the
reverse order of removal.
9. Clean up any spilled engine coolant.
10. Refill the radiator with engine coolant, then bleedthe air from the cooling system with the heater
valve open (see step 8 on page 10-7).
11. Install the splash shield, then install the engine
under cover (see step 42 on page 5-19).
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10-610-6
Cooling System
Coolant Check Coolant Replacement
A
B
A
A
78 Nm(8.0 kgfm, 58 lbfft)
1. Look at the coolant level in the coolant reservoir
tank. Make sure it is between the MAX mark (A) and
the MIN mark (B).
2. If the coolant level in the coolant reservoir tank is at
or below the MIN mark, add coolant to bring it
between the MIN mark and the MAX mark, then
inspect the cooling system for leaks.
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 five clips and the two bolts securing
the engine undercover, then open the engine
undercover (see step 2 on page 8-10).
4. Loosen the drain plug (A), and drain the coolant.
5. Remove the drain bolt (A) from the rear side of the
engine block.
6. After the coolant has drained, reinstall the drain
bolt with a new washer.
7. Tighten the radiator drain plug securely.
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Engine Coolant Capacities (Including the coolant
reservoir capacity of 0.4 L (0.11 US gal))
At Coolant Change: 4.75 L (1.25 US gal)
After Engine Overhaul: 6.0 L (1.59 US gal)
10-7
A9.8 Nm(1.0 kgfm, 7.2 lbfft)
A
B
8. Loosen the air bleed bolt (A) on the connecting pipe
joint.
9. Pour Honda Long Life Antifreeze/Coolant Type 2
(P/N OL999-9001) into the radiator, and tighten the
bleed bolt as soon as coolant starts to run out in a
steady stream.
10. Pour Honda Long Life Antifreeze/Coolant Type 2
into the radiator up to the base of the filler neck.
NOTE:
Always use Honda Long Life Antifreeze/Coolant
Type 2. Using a non-Honda coolant can result in
corrosion, causing the cooling system to
malfunction or fail.
Honda Long Life Antifreeze/Coolant Type 2 is a
mixture of 50 % antifreeze and 50 % water. Do
not add water.
11. Install the radiator cap loosely.
12. Start the engine and let it run until it warms up (the
radiator fan comes on at least twice).
13. Turn off the engine. Check the level in the radiator
and add Honda Long Life Antifreeze/Coolant Type 2
if needed.
14. Fill the coolant reservoir to between the MAX mark
(A) and the MIN mark (B) with Honda Long Life
Antifreeze/Coolant Type 2.
15. Put the radiator cap on tightly, then run the engine
again and check for leaks.
16. Clean up any spilled engine coolant.
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Removal Installation
10-8
Cooling System
Thermostat Replacement
D
B
C
A
AB
A
DC
A
B
6 x 1.0 mm12 Nm(1.2 kgfm, 8.7 lbfft)
1. Drain the engine coolant (see page 10-6).
2. Remove the air cleaner assembly (see page 11-381).
3. Remove the upper radiator hose (A), the lower
radiator hose (B), the heater hoses (C), and the
water bypass hose (D).
4. Remove the water passage (A), then remove the
thermostat (B).
1. Remove old liquid gasket from the water passage,
thermostat housing mating surfaces, bolts, and bolt
holes.
2. Apply a 1.5 mm wide bead of the liquid gasket on
the water passage, P/N 08717-0004, 08718-0001,
08718-0003, or 08718-0009, along the broken lines
(A). Install the component within 5 minutes of
applying the liquid gasket.
NOTE:
If you apply liquid gasket P/N 08718-0012, the
component must be installed with 4 minutes.
If too much time has passed after applying the
liquid gasket, remove the old liquid gasket andresidue, then reapply new liquid gasket.
3. Install the rubber seal (A) on the thermostat (B),
then install the thermostat with the pin (C) up.
4. Install the water passage (D).
NOTE: After assembly, wait at least 30 minutes
before filling the engine with coolant.
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10-9
D
B
C
A
5. Install the upper radiator hose (A), the lower
radiator hose (B), the heater hoses (C), and the
water bypass hose (D).
6. Install the air cleaner assembly (see page 11-381).
7. Refill the radiator with engine coolant, and bleed
air from the cooling system with the heater valve
open (see step 8 on page 10-7).
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10-1010-10
Cooling System
Drive Belt Inspection Drive Belt Replacement
A
B
A
B
1. Inspect the belt for cracks and damage. If the belt is
cracked or damaged, replace it.
2. Check that the auto-tensioner indicator (A) is within
the standard range (B) as shown. If it is out of the
standard range, replace the drive belt (see page
10-10).
1. Move the auto-tensioner (A) to relieve tension from
the drive belt (B), and remove the drive belt.
2. Install the new belt in the reverse order of removal.
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Auto-Tensioner Spring Torque:
10 13 Nm (1.0 1.3 kgm, 7.3 9.4 lbfft)
10-11
Drive Belt Auto-tensioner Inspection
A
B
C
D
E
F
30 30
1. Check whether there is a change in the position of
the auto-tensioner indicator before starting the
engine and after starting the engine. If there is a
change in the position, replace the auto-tensioner.
2. Check for abnormal noise from the tensioner pulley.
If you hear abnormal noise, replace the tensioner
pulley.
3. Remove the drive belt (see page 10-10).
4. Move the auto-tensioner within its limit with the
belt tension release tool in the direction shown.
Check that the tensioner moves smoothly and
without any abnormal noise. If the tensioner does
not move smoothly or you hear abnormal noise,
replace the auto-tensioner.
5. Remove the auto-tensioner (see page 10-12).
6. Install the tensioner pulley.
7. Clamp the auto-tensioner (A) by using two 8 mm
bolts (B) and a vise (C) as shown. Do not clamp the
auto-tensioner itself.
8. Set the torque wrench (D) on the pulley bolt.
9. Align the indicator (E) on the tensioner arm with the
center mark (F) on the tensioner base by using the
torque wrench, and measure the torque. If the
torque value is out of specification, replace the
auto-tensioner.
NOTE: If the indicator exceeds the center mark,recheck the torque.
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10-12
Cooling System
Drive Belt Auto-tensioner Replacement
6 x 1.0 mm14 Nm(1.4 kgfm, 10 lbfft)
10 x 1.25 mm27 Nm(2.8 kgfm, 20 lbfft)
8 x 1.25 mm22 Nm(2.2 kgfm, 16 lbfft)
1. Remove the drive belt (see page 10-10).
2. Remove the water pump pulley bolts.
3. Remove the auto-tensioner pulley.
4. Remove the auto-tensioner.
5. Install the drive belt auto-tensioner in the reverse
order of removal.
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10-13
Radiator and Fan Replacement
6 x 1.0 mm9.8 Nm
(1.0 kgfm, 7.2 lbfft)
A
B
A
B6 x 1.0 mm9.8 Nm(1.0 kgfm, 7.2 lbfft)
A
C
C
B6 x 1.0 mm9.8 Nm(1.0 kgfm, 7.2 lbfft)
AC
1. Drain the engine coolant (see page 10-6).
2. Remove the front wheels.
3. Remove the splash shield and the engine
undercover (see step 22 on page 5-5).
4. Remove the engine cover (see step 7 on page 5-3).
5. Remove the resonator (see page 11-383).
6. Remove the intake air duct (see step 9 on page 5-3).
7. Remove the air cleaner assembly (see page 11-381).
8. Remove the front grille cover.
9. Remove the clips (A) and the radiator mount upper
bracket/cushion (B).
10. Disconnect the hood latch switch connector (A),
then remove the mounting bolts (B) and the clips
(C).
11. Remove the reserve tank hose (A) and the
mounting bolts (B), then remove the water filler (C).
(contd)
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10-14
Cooling System
Radiator and Fan Replacement (contd)
A
B
C
D
D
6 x 1.0 mm9.8 Nm(1.0 kgfm, 7.2 lbfft)
C6 x 1.0 mm12 Nm(1.2 kgfm, 8.7 lbfft)
A
B
A
B
C
D
12. Remove the harness clamps (A), then disconnect
the radiator fan motor connector (B), A/C
condenser fan motor connector (C), and the
harness clamps (D).
13. Remove the bulkhead.
14. Remove the upper radiator hose (A) and the lower
radiator hose (B), then remove the water lower pipe
mounting bolts (C).
15. Raise the vehicle on the lift to full height.
16. Drain the CVT fluid (CVTF) (see page 14-208).
17. Remove the ATF cooler hoses (A) and the lower
radiator hose (B).
18. Disconnect the engine coolant temperature (ECT)
sensor 2 connector (C), then remove the clamp (D).
19. Lower the vehicle on the lift.
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10-15
A
B
A6 x 1.0 mm7 Nm(0.7 kgfm, 5 lbfft)
B
C
C
D
E
B10 x 1.25 mm12 Nm(1.2 kgfm, 8.7 lbfft)
D
E
A
20. Remove the upper radiator hose (A) and the water
filler hose (B).
21. Remove the mounting bolts (A), then pull up the
radiator fan shroud assembly (B) and the A/C
condenser fan shroud assembly (C).
22. Pull up the radiator (A), then remove the ECT
sensor 2 (B), the drain plug (C), the O-rings (D), and
the lower cushions (E).
23. Install the radiator in the reverse order of removal.
Make sure the upper and lower cushions are set
securely.
24. Install the bulkhead in the reverse order of removal.
Apply touch-up paint to the bulkhead mounting
bolts.
25. Adjust the hood latch alignment (see page 20-125).
26. Fill the radiator with engine coolant, then bleed the
air from the cooling system (see step 8 on page
10-7).
Replace.
Replace.
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10-16
Fan Controls
Component Location Index
UNDER-HOODFUSE/RELAY BOX
FAN CONTROL RELAY
A/C CONDENSER FAN RELAYRADIATOR FAN RELAY
RADIATOR FAN ASSEMBLY
ENGINE COOLANT TEMPERATURE(ECT) SENSOR 2
A/C CONDENSER FAN ASSEMBLY
Test, page 22-59
Test, page 22-59Test, page 22-59
Motor Test, page 10-4
Replacement, page 11-238
Motor Test, page 10-4
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Symptom Diagnostic Procedure Also check for
10-17
Symptom Troubleshooting Index
Engine overheats 1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
Check the coolant level.
Check for any engine coolant leakage (from
gaskets, hoses, O-rings, etc.).
Check for dirt, leaves, or insects on the radiator
and the A/C condenser.
Check for deteriorated coolant.
Check for damaged or deformed fan shroud.
Inspect the fan motors (see page 10-4) or fan
relays (see page 22-59).
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 plugged or deteriorated radiator
hose.
Check for plugged heater core or hoses.
Check for 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 206 F
(97 C)
Radiator fan high speed circuit troubleshooting
(see page 10-19).
Cleanliness and
tightness of all
connectors
With the A/C off and the engine
coolant temperature at 206 F
(97 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 206 F
(97 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 short in the wire
between fan control relay 5P socket terminal No. 1
and radiator 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 204 F
(95 C)
Check for short in the wire between A/C condenser
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 short in the wire between radiator 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 page 21-77).
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 page 21-81).
Cleanliness and
tightness of all
connectors
Both the radiator fan and the A/C
condenser fan do not run at highspeed when the engine coolant
temperature is above 206 F
(97 C)
Check for open in the wire between A/C condenser
fan relay 4P socket terminal No. 3 and PCM connectorterminal A5.
Cleanliness and
tightness of allconnectors
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10-18
Fan Controls
Circuit Diagram
RED
No.15(7.5A)
2
3
4
1
No.7(20 A)
No.36(10A)
14
3 2
4
3
No.2(50 A)
WHTBAT
IG2
IGNITION SWITCHUNDER-HOOD FUSE/RELAY BOX
No.1 (100 A)
UNDER-DASHFUSE/RELAY BOX
A/CCONDENSERFANRELAY
RADIATORFANRELAY
BLK
12 VBATTERY
ORN
(15A)No.11
PGM-FISUBRELAY
No.6(20A)
G301
1
2
A/CCONDENSERFANMOTOR
RADIATORFANMOTOR
1
2
G301
GRY BLU PUR BRNPNK
GRN BLK
PCM A21 A33 A9 A5 A4
ENGINE COOLANT TEMPERATURE (ECT)SENSOR 2
A/CDIODE
1
43 2
5
FANCONTROLRELAY
2 1
RADIATORFANDIODE
BLK
IG2HOTinON (II)
1
2
SUBRLY ECT2 SG3 FANH FANL
F14 F1 F11 F12 F7 F2
3 4H1 C3 G12
D1
F16
12 V
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YES
NO
YES
NO
YES
NO
YES
NO
YES
NO
10-19
Radiator Fan High Speed Circuit Troubleshooting
RADIATOR FAN RELAY 4P SOCKET
RADIATOR FAN RELAY 4P SOCKET
JUMPER WIRE
RADIATOR FAN RELAY 4P SOCKET
1. Check the No. 7 (20 A) fuse in the under-hood
fuse/relay box.
Go to step 2.
Replace the fuse and recheck.
2. Remove the radiator fan relay from the under-hood
fuse/relay box and test it (see page 22-59).
Go to step 3.
Replace the radiator fan relay.
3. Measure the voltage between radiator fan relay 4P
socket terminal No.1 and body ground.
Go to step 4.
Repair open in the wire between radiator fan
relay 4P socket terminal No. 1 and the under-hood
fuse/relay box.
4. Connect radiator fan relay 4P socket terminals
No. 1 and No. 2 with a jumper wire.
Go to step 5.
Repair open in the wire between 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 the voltage between radiator fan relay 4P
socket terminal No. 4 and body ground.
Repair open in the wire between radiator fan
relay 4P socket terminal No. 4 and powertrain
control module (PCM) connector terminal A4.
Repair open in the wire between radiator fan
relay 4P socket terminal No. 3 and the under-dash
fuse/relay box.
Terminal side of female terminals
Terminal side of female terminals
Terminal side of female terminals
Is the fuse OK?
Is the relay OK?
Is there battery voltage?
Does the radiator fan run at high speed?
Is there battery voltage?
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