2007 Honda Civic Hybrid - Engine Cooling

7/23/2019 2007 Honda Civic Hybrid - Engine Cooling

1/19

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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2/19

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


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

06/09/19 11:02:47 61SNC010_100_0004


5/19

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).


3. Drain the engine coolant (see page 10-6).

4. Remove the water pump pulley mounting bolts.


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).

06/09/19 11:02:49 61SNC010_100_0005


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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.

06/09/19 11:02:51 61SNC010_100_0007


8/19

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)


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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9/19

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).

06/09/19 11:02:52 61SNC010_100_0009


10/19

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.

06/09/19 11:02:53 61SNC010_100_0010


11/19

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.


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.


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.

06/09/19 11:02:54 61SNC010_100_0011


12/19

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)


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.

06/09/19 11:02:55 61SNC010_100_0012


13/19

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


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)

06/09/19 11:02:56 61SNC010_100_0013


14/19

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.

06/09/19 11:02:57 61SNC010_100_0014


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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.

06/09/19 11:02:59 61SNC010_100_0015


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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


Motor Test, page 10-4

06/09/19 11:03:00 61SNC010_100_0016


17/19

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


(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


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


condenser fan do not run at highspeed when the engine coolant


(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

06/09/19 11:03:01 61SNC010_100_0017


18/19

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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19/19

YES

NO

YES

NO

YES

NO

YES

NO

YES

NO

10-19

Radiator Fan High Speed Circuit Troubleshooting

RADIATOR FAN RELAY 4P SOCKET


JUMPER WIRE


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.


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.


relay 4P socket terminal No. 4 and powertrain

control module (PCM) connector terminal A4.


relay 4P socket terminal No. 3 and the under-dash

fuse/relay box.

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?

06/09/19 11:03:02 61SNC010_100_0019

Documents

2007 Honda Civic Hybrid - Engine Cooling