14-1
GROUP 14
ENGINE COOLING
CONTENTS
GENERAL INFORMATION . . . . . . . .14-2
SERVICE SPECIFICATIONS . . . . . . .14-2
LUBRICANT . . . . . . . . . . . . . . . . . . . .14-2
SEALANTS . . . . . . . . . . . . . . . . . . . .14-3
SPECIAL TOOLS . . . . . . . . . . . . . . . .14-3
TROUBLESHOOTING . . . . . . . . . . . .14-5
INSPECTION CHART FOR TROUBLE
SYMPTOMS . . . . . . . . . . . . . . . . . . . . . . . . 14-5
INSPECTION PROCEDURE FOR
TROUBLE SYMPTOMS . . . . . . . . . . . . . . . 14-6
ON-VEHICLE SERVICE . . . . . . . . . . .14-22
ENGINE COOLANT LEAK CHECK . . . . . . 14-22
RADIATOR CAP VALVE OPENING
PRESSURE CHECK . . . . . . . . . . . . . . . . . . 14-22
ENGINE COOLANT REPLACEMENT . . . . 14-22
CONCENTRATION MEASUREMENT . . . . 14-23COOLING FAN MOTOR DRIVE CONTROL
UNIT CHECK . . . . . . . . . . . . . . . . . . . . . . . . 14-23
FAN CONTROL RELAY CONTINUITY
CHECK . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14-24
COOLING FAN MOTOR CHECK . . . . . . . . 14-25
THERMOSTAT . . . . . . . . . . . . . . . . . .14-26
REMOVAL AND INSTALLATION . . . . . . . . 14-26
INSPECTION . . . . . . . . . . . . . . . . . . . . . . . . 14-27
WATER PUMP . . . . . . . . . . . . . . . . . .14-29
REMOVAL AND INSTALLATION <4G1> . . 14-29
REMOVAL AND INSTALLATION <4G6> . . 14-30
WATER HOSE AND WATER PIPE . .14-31
REMOVAL AND INSTALLATION <4G1> . . 14-31
REMOVAL AND INSTALLATION <4G6> . . 14-33
INSPECTION . . . . . . . . . . . . . . . . . . . . . . . . 14-34
RADIATOR . . . . . . . . . . . . . . . . . . . . .14-35
REMOVAL AND INSTALLATION . . . . . . . . 14-35
ON-VEHICLE SERVICE
ENGINE COOLING14-23
5. Apply the designated sealant to the screw area of
the cylinder block drain plug, and then tighten to
the standard torque.
Specified sealant: 3M Nut Locking Part
No.4171 or equivalent
Tightening torque:
40 ± 5 N⋅m <4G1>
44 ± 5 N⋅m <4G6>
6. Securely tighten the drain plug of the radiator.
7. Reinstall the radiator condenser tank.
CAUTION
Do not use alcohol or methanol anti-freeze or any
engine coolants mixed with alcohol or methanol
anti-freeze. The use of an improper anti-freeze
can cause corrosion of the aluminium
components.
8. By referring to the section on coolant, select an
appropriate concentration for safe operating
temperature within the range of 30 to 60%. Use
special tool LLC changer (MB991871) to refill the
coolant. A convenient mixture is a 50% water and
50% antifreeze solution (freezing point: −31°C).
Recommended antifreeze: DIAQUEEN SUPER
LONG LIFE COOLANT or equivalent
Quantity:
5.0 L <4G1>
7.0 L <4G6>
NOTE: For how to use special tool MB991871,
refer to its manufacturer’s instructions.9. Reinstall the radiator cap.
10.Start the engine and let it warm up until the
thermostat opens.
11.After repeatedly revving the engine up to 3,000
r/min several times, then stop the engine.
12.Remove the radiator cap after the engine has
become cold, and pour in coolant up to the brim.
Reinstall the cap.
CAUTION
Do not overfill the radiator condenser tank.
13.Add coolant to the radiator condenser tank
between the "F" and "L" mark if necessary.
CONCENTRATION MEASUREMENTM1141001100352
Measure the temperature and specific gravity of the
engine coolant to check the antifreeze concentration.
Standard value: 30 − 60% (allowable
concentration range)
Recommended antifreeze: DIAQUEEN SUPER
LONG LIFE COOLANT or equivalent
CAUTION
If the concentration of the anti-freeze is below
30%, the anti-corrosion property will be
adversely affected. In addition, if the
concentration is above 60%, both the
anti-freezing and engine cooling properties will
decrease, affecting the engine adversely. For
these reasons, be sure to maintain the
concentration level within the specified range.
COOLING FAN MOTOR DRIVE CONTROL
UNIT CHECK
M1141006100216
1. Remove the cooling fan motor drive control unit
connector.
2. Turn the ignition switch to the "ON" position, and
measure the voltage between terminal 1 and 3 at
the harness side connector.
Standard value: system voltage
AC200625
Cylinder block
drain plug
AC
AC303612AB
MB991871
AIR HOSE
AC103195
Y1716AU
1 23
AC
Cooling fan motor
drive control unit
ON-VEHICLE SERVICE
ENGINE COOLING14-25
COOLING FAN MOTOR CHECKM11410071000601. Remove the cooling fan motor connector.
2. Check to see that the cooling fan motor of the
radiator turns when applying battery power
between the connector terminal 1 and 2 of the
cooling fan motor. Also check to see that there is
no abnormal sound coming from the cooling fan
motor at this time.
3. If the cooling fan motor is defective, replace it.
(Refer to P.14-35).
1 2
AC303501AB
Cooling fan motor drive control unit
Cooling fan motor
(L.H.) connector
1 2
AC303502AB
Cooling fan motor
drive control unit
Cooling fan motor
(R.H.) connector
<4G1 with A/C>
ECU
COMPONENT LOCATIONS70-3
NOTE: *: also equipped on the rear doors.
AC304537
JK*
AE
AC100209AC
A
ABS-ECU
Hydraulic unit
AC206790
A
AD
ABS-ECU
Hydraulic unit
AC301728AB
BFront-ECU
Battery
AC300571
C
ACRadiator fan
Cooling fan motor
drive control unit
AC301746
DColumn switch
(incorporating
column-ECU)
AB
AC301732AB
E
A/C-ECU
