ECU MITSUBISHI LANCER 2006 Workshop Manual
[x] Cancel search | Manufacturer: MITSUBISHI, Model Year: 2006, Model line: LANCER, Model: MITSUBISHI LANCER 2006Pages: 800, PDF Size: 45.03 MB
Page 20 of 800

TROUBLESHOOTING
ENGINE COOLING14-6
INSPECTION PROCEDURE FOR 
TROUBLE SYMPTOMS
INSPECTION PROCEDURE 1: Cooling Fan (L.H.) and Cooling Fan (R.H.) <4G1 (Vehicles with A/C)> or 
A/C Condenser Fan <4G6> do not Operate
Wire colour code
B : Black     LG : Light green
G : Green     L : Blue      
W : White     Y : Yellow
SB : Sky blue     BR : Brown 
O : Orange     GR : Gray  
R : Red     P : Pink     V : Violet 
FAN CONTROL 
RELAY
              A-09XENGINE CONTROL 
RELAY
B-16X
AC303577
A-18-1
COOLING FAN
MOTOR (L.H.)
COOLING FAN
MOTOR (R.H.)
<4G1 (VEHICLES
WITH A/C>
OR
A/C CONDENSER
FAN MOTOR <4G6> A-18-2
A-18
COOLING FAN
MOTOR DRIVE
CONTROL UNIT 1    A-13 
12  C-111 
ENGINE-ECU 
ENGINE-A/T-ECU 
21  C-123 
18  C-122 
615 121179
810234
(MU802322)
(MU801824)
C-123
(MU803784)C-122
(MU802611)A-13
C-111 L
L 2
22 11
1B
L
2
3
4
B-W
FUSIBLE
LINK No.2
B3
1
R-Y
R-Y
8    A-13 
11  C-111 
615 121179
810234
(MU802611)
J/C (6)
C-12 
C-134 
R-Y
3328
A-13
C-111
Cooling Fan (L.H.) and Cooling Fan (R.H.) or A/C Condenser Fan Drive Circut
AB
CIRCUIT OPERA T ION
•The cooling  fan motor drive  contro l unit is pow-
ered from  fusible link (2).
•The engine-ECU  
/T>   use s  in pu t  sign als fro m   th e A/C switch ,  t h e  
water t
e mpe r ature sensor unit and  the vehicle 
speed sensor 
senso
r   to control the speed  of the  coo ling  
fan
 moto r (L.H.) and  the cooling fa n mot o r (R.H.) 
<4G1 (V
ehicles wit h  A/C)> or A/C co ndenser fan  
motor <4G6>. 
Page 21 of 800

TROUBLESHOOTING
ENGINE COOLING14-7
•The engine-ECU 
 controls the cooling fan motor drive control 
unit to activate the cooling fan motor (L.H.) and 
the cooling fan motor (R.H.) <4G1 (Vehicles with 
A/C)> or A/C condenser fan motor <4G6>.
TECHNICAL DESCRIPTION
•The cause could be a malfunction of the cooling 
fan motor drive control unit power supply or earth 
circuit.
•If the communication line wiring harness between 
the cooling fan motor drive control unit and the 
engine-ECU 
short-circuited to earth, the cooling fan motor 
(L.H.) and the cooling fan motor (R.H.) <4G1 
(Vehicles with A/C)> or the A/C condenser fan 
motor <4G6> will not rotate.
•The cause could also be a malfunction of the 
cooling fan motor (L.H.). 
•The cause could also be a malfunction of imput 
signal from the A/C switch, the water temperature 
sensor unit and the vehicle speed sensor 
or the output shaft speed sensor  to the 
engine-ECU 
•The cause could also be a malfunction of the 
cooling fan motor drive control unit or the 
engine-ECU 
TROUBLESHOOTING HINTS
•Malfunction of fusible link (2)
•Malfunction of fan control relay
•Malfunction of cooling fan motor (L.H.) 
•Malfunction of cooling fan motor drive control unit
•Malfunction of engine-ECU 
engine-A/T-ECU 
•Damaged wiring harness or connector
DIAGNOSIS
STEP 1. Check the cooling fan motor (L.H.). 
Refer to P.14-24.
Q: Is the cooling fan motor (L.H.) in good condition?
YES : Go to Step 2 .
NO : Replace the cooling fan motor (L.H.) (Refer 
to 
P.14-33) <4G1> (Refer to P.14-35) 
<4G6>. Then go to Step 24 .
STEP 2. Measure the power supply voltage at 
cooling fan motor drive control unit connector 
A-18.
AC100293
A-18
321
Connector: A-18
AD
(1)D isconn ect cooling f an motor drive contro l unit 
conne ctor  A-18 a nd measure  wirin g  har ness side  
connector .
(2)T urn t he ig nition switch t o  the "ON" positio n.
AC000246AF
A-18 Connector
(Component side)
(3)M easu r e the volt age  between  cooling  fan motor 
drive control unit con nect o r A-18 te rmin al 3 a nd 
bod y ea rth.
•The voltage shou ld measu r e syste m  volt age.
(4)T urn t he ig nition switch t o  the "L OCK" (OF F ) 
position.
(5)C onne ct cooling fa n mot o r drive control unit  
connector A-18.
Q:Is t h e mea s ure d  volt a g e sy ste m   v o lt ag e?
YES : Go to S t ep 1 7  .
NO : Go to S t ep 3  . 
Page 27 of 800

TROUBLESHOOTING
ENGINE COOLING14-13
STEP 18. Check the cooling fan motor drive 
control unit connector A-18.
AC100293
A-18
321
Connector: A-18
AD
Q:Is t h e con n ec tor   in goo d  c ondit i o n ?
YES : Go to S t ep 19  .
NO : Repa ir or replace the   conne ctor . Th en go to 
S
t ep 24 
.
STEP 1 9 . Check th e harness  wire b e twee n 
cooling fa
n motor drive  control uni t connec tor 
A-1
8  terminal  1 and b ody earth.
AC100293
A-18
321
Connector: A-18
AD
Q:Is t h e har n es s wire in good   c ondition ?
YES : An intermittent malf unction is suspe c ted  
(Refer to  GROUP 00  - How to use 
troub lesh ooting 
P.00-5).
NO : Repa ir the dama ged harness wire. Then go 
to S
t ep 2 4  
.
STEP 2 0 . Check t he cooli ng fan m o tor drive 
control unit 
connecto r  A-18 , intermed iate 
connecto
r  A-13  
C-1
23  
T >.
AC100293
A-18
321
Connector: A-18
AD
AC303526
Connector: A-13 
AB
A-13
A-13
AC303527
Connector: C-111 
AB
C-111
C-111
615 121179
810234 
Page 28 of 800

AC303555AB
Connector: C-123 
or
C-122 
C-123 
Engine-ECU 
engine-A/T-ECU 
C-122 
TROUBLESH OOTING
ENGINE COOLING14-14
Q: Are   t h es e con n ec tor s  in   go od con d ition?
YES : Go to S t ep 21  .
NO : Repa ir or replace the   conne ctor . Th en go to 
S
t ep 24 
.
ST EP 2 1 . Check t he harness  wire b e twe en 
cooling f
an motor drive  control uni t connec tor 
A-1
8  te rm inal  2 an d en gine-ECU c onnec tor C-123  
terminal 2
1  
C-1
22 termina l  18 .
AC100293
A-18
321
Connector: A-18
AD
AC303555AB
Connector: C-123 
C-123 
or
C-122 
C-123 
Engine-ECU 
engine-A/T-ECU 
C-122 
Q: Are   t h es e har n es s wires   in go od cond it ion?
YES : Go to S t ep 2 2  .
NO : Repa ir the dama ged harness wire. Then go 
to S
t ep 2 4  
. 
Page 29 of 800

TROUBLESHOOTING
ENGINE COOLING14-15
STEP 22. Check the cooling fan motor drive 
control unit.
AC303555AB
Connector: C-123 
or
C-122 
C-123 
Engine-ECU 
engine-A/T-ECU 
C-122 
(1) D isconn ect e ngin e -ECU conne ctor C-12 3 
or e ngine -A/T -ECU conne ctor C-12 2 .
AC303559
C-122 connector 
(Harness side connector: ECU side view)
AB
C-123 connector 
(Harness side connector: ECU side view)
(2)P ull out conne ctor t e rminal p i n 21  
 to  discon nect  conn ector .
(3)R eco nnect  t he con necto r  with conn ector ter m in al 
pin still  removed.
(4)T urn t he ig nition switch to  the "ON" positio n.
(5)C heck fo r the cooling fan  opera t ion.
•The cooling fan ro t a t e s.  (with conne ctor  termi-
nal pi n 21  
•The cooling fan stop s. (When  con necto r ter-
minal pi n  21  
to the 
body earth.)
(6)T urn t he ig nition switch t o  the "OFF" po sit i on.
(7)D isconn ect e ngin e -ECU conne ctor C-12 3 
or e ngine -A/T -ECU conne ctor C-12 2 , a nd 
push in con nect o r terminal pin  21 
 to  discon nect  conn ector .
(8)R econnect the con necto r  with conn ector   te rmin al 
pin still  inst alled.
Q:Doe s  the  cooling fa n rot a te ?   And wh en th e 
c onne ct or te rmin a l  p i n   is co nnec t e d  to t h e bod y 
e a rt h, d o es  t h e  co olin g f a n  s t op ?
YES : Go to S t ep 2 3  .
NO : Replac e th e coo lin g fan motor d r ive  con t rol 
unit (Refer to 
P.14-33) <4G1>  (Refer to 
P.14-35) <4G6>. Then  go to  S t e p  24 .
STEP 2 3 . M.U.T . -II/III  self-dia g code
Check if an  MPI system self- d iag  code  is  set. (Ref er 
to GROUP 
13A - T r ouble shooting 
P.13A-9) <4G1> 
or (Refer to GROUP 13 B - T r ouble sho o ting  
P.13B-9) <4G6>.
Q:Diagn o sis co de se t?
YES : Inspecti on chart fo r dia gnosis code  (Re f er 
to GROUP 13A - T r ou ble shoot ing 
P.13A-15) <4G1 > or Inspection chart  for 
diagnosis code  (Re f er to GROUP 13B - 
T
r ouble sh ootin g 
P.13B-15) <4G6>.
NO : Replac e th e engine-ECU 
engine-A/T
- ECU  (Refer  to GROUP 
13A 
P.13A- 384). Then go t o  S t ep 24 .
STEP 2 4 . Check t he sym ptoms.
Q:Doe s  the  cooling fa n moto r  ( L .H.)  and t h e coo l ing 
fa n  mo to r ( R .H. )   <4G 1  (V ehicles  with A/ C)>  or A/C  
c onde nse r   fa n mo tor  <4G6> o p era t e  c o rre ct ly ?
YES : This symptoms is comple te.
NO : Return to  S t ep 1 . 
Page 30 of 800

TROUBLESHOOTING
ENGINE COOLING14-16
INSPECTION PROCEDURE 2: Cooling Fan (L.H.) and Cooling Fan (R.H.) <4G1 (Vehicles with A/C)> or 
A/C Condenser Fan <4G6> do not Change Speed or Stop
COOLING FAN (L.H.) AND COOLING FAN 
(R.H.) OR A/C CONDENSER FAN DRIVE 
CIRCUIT
Refer to P.14-6.
CIRCUIT OPERATION
Refer to P.14-6.
TECHNICAL DESCRIPTION
•If the communication line wiring harness between 
the cooling fan motor drive control unit and the 
engine-ECU 
 is open, the cooling fan motor (L.H.) and 
the cooling fan motor (R.H.) <4G1 (Vehicles with 
A/C)>, or the A/C condenser fan motor <4G6> 
rotate to prevent the engine from overheating.
•If the system voltage is continuously supplied to 
the cooling fan motor drive control unit by a fan 
motor relay malfunction and a short circuit on the 
cooling fan motor drive control unit power supply 
wiring harness, the cooling fan motor (L.H.) and 
the cooling fan motor (R.H.) <4G1 (Vehicles with 
A/C)>, or the A/C condenser fan motor <4G6> 
rotate.
•The cause could also be a malfunction of the 
cooling fan motor (L.H.). 
•The cause could also be a malfunction of input 
signal from the A/C switch, the water temperature 
sensor unit and the vehicle speed sensor 
or the output shaft speed sensor  to the 
engine-ECU 
•The cause could also be a malfunction of the 
cooling fan motor drive control unit or the 
engine-ECU 
TROUBLESHOOTING HINTS
•Malfunction of fan control relay
•Malfunction of cooling fan motor (L.H.) 
•Malfunction of cooling fan motor drive control unit
•Malfunction of engine-ECU 
engine-A/T-ECU 
•Damaged wiring harness or connector
DIAGNOSIS
STEP 1. Check the fan control relay.
Refer to P.14-23.
Q: Is the fan control relay in good condition?
YES : Go to Step 2 .
NO : Replace the fan control relay. Then go to 
Step 8 
.
STEP 2. Check the fan control relay connector 
A-09X.
AC303510AB
Fan control relay
Relay boxConnector: A-09X
A-09X
Q:Is t h e con n ec tor   in goo d  c ond it io n?
YES : Go to S t ep 3  .
NO : Repa ir th e con nect o r or rep l ace the re lay 
box. Then
 go to  S t ep  8 
.
STEP 3 .  Check the  harness  wire be twee n fan 
control relay
 connec tor  A-0 9 X terminal 2  and 
cooling f
an motor drive  control uni t connec tor 
A-1
8  terminal  3.
AC303510AB
Fan control relay
Relay boxConnector: A-09X
A-09X 
Page 31 of 800

AC100293
A-18
321
Connector: A-18
AD
TROUBLESHOOTING
ENGINE COOLING14-17
Q: Is t h e har n es s wire in good   c ondition ?
YES : Go to S t ep 4  .
NO : Repa ir the dama ged harness wire. Then go 
to S
t ep 8  
.
STEP 4.  Ch eck the  cooling  fan moto r d r iv e 
control unit c
onnecto r  A-18 , intermed iate 
connecto
r  A-13  
C-1
23  
.
AC100293
A-18
321
Connector: A-18
AD
AC303526
Connector: A-13 
AB
A-13
A-13
AC303527
Connector: C-111 
AB
C-111
C-111
615121179
810234
AC303555AB
Connector: C-123 
C-123 
or
C-122 
C-123 
Engine-ECU 
engine-A/T-ECU 
C-122 
Q: Are   t h es e con n ec tor s  in   g ood con d ition?
YES : Go to S t ep 5  .
NO : Repa ir or replace the   conne ctor .   Th en go to 
S
t ep 8 
. 
Page 32 of 800

TROUBLESHOOTING
ENGINE COOLING14-18
STEP 5. Check the harness wire between cooling 
fan motor drive control unit connector A-18 
terminal 2 and engine-ECU connector C-123 
terminal 21 
C-122 terminal 18 .
AC100293
A-18
321
Connector: A-18
AD
AC303555AB
Connector: C-123 
or
C-122 
C-123 
Engine-ECU 
engine-A/T-ECU 
C-122 
Q: Are   t h es e har n es s wires   in goo d cond it ion?
YES : Go to S t ep 6  .
NO : Repa ir the dama ged harness wire. Then go 
to S
t ep 8  
.
STEP 6 .  Check the  cooling  fan moto r d r iv e 
control unit.
AC303555AB
Connector: C-123 
C-123 
or
C-122 
C-123 
Engine-ECU 
engine-A/T-ECU 
C-122 
(1) D isconn ect e ngin e -ECU conne ctor C-12 3 
or e ngine -A/T -ECU conne ctor C-12 2 .
AC303559
C-122 connector 
(Harness side connector: ECU side view)
AB
C-123 connector 
(Harness side connector: ECU side view)
(2)P ull out conne ctor  terminal p i n 21  
 to  discon nect  conn ector .
(3)R econnect the con necto r  with conn ector   te rmin al 
pin still  removed.
(4)T urn t he ig nition switch t o  the "ON" positio n.
(5)C heck fo r the cooling fan  opera t ion.
•The cooling fan ro t a t e s.  (with conne ctor  termi-
nal pi n 21  
•The cooling fan stop s. (When  con necto r ter-
minal pi n  21  
to the 
body earth.)
(6)T urn t he ig nition switch t o  the "OFF" po sit i on.
(7)D isconn ect e ngin e -ECU conne ctor C-12 3 
or e ngine -A/T -ECU conne ctor C-12 2 , a nd 
push in con nect o r terminal pin  21 
 to  discon nect  conn ector . 
Page 33 of 800

TROUBLESHOOTING
ENGINE COOLING14-19
(8) Reconnect the connector with connector terminal 
pin still installed.
Q: Does the cooling fan rotate?  And when the 
connector terminal pin is connected to the body 
earth, does the cooling fan stop? 
YES : Go to Step 7 .
NO : Replace the cooling fan motor drive control 
unit (Refer to 
P.14-33) <4G1> (Refer to 
P.14-35) 4G6>. Then go to Step 8 .
STEP 7. M.U.T.-II/III self-diag code
Check if an MPI system self-diag code is set. (Refer 
to GROUP 13A - Trouble shooting 
P.13A-9) <4G1> 
or (Refer to GROUP 13B - Trouble shooting 
P.13B-9) <4G6>.
Q: Diagnosis code set?
YES : Inspection chart for diagnosis code (Refer 
to GROUP 13A - Trouble shooting 
P.13A-15) <4G1> or Inspection chart for 
diagnosis code (Refer to GROUP 13B - 
Trouble shooting 
P.13B-15) <4G6>.
NO : Replace the engine-ECU 
engine-A/T-ECU  (Refer to GROUP 
13A 
P.13A-384). Then go to Step 8 .
STEP 8. Check the symptoms.
Q: Does the cooling fan motor (L.H.) and the cooling 
fan motor (R.H.) <4G1 (Vehicles with A/C)> or A/C 
condenser fan motor <4G6> operate correctly?
YES : This symptoms is complete.
NO : Return to Step 1 .
INSPECTION PROCEDURE 3: Cooling Fan (L.H.) does not Operate {When Cooling Fan (R.H.) <4G1> or 
A/C Condenser Fan <4G6> Operate} 
COOLING FAN (L.H.) AND COOLING FAN 
(R.H.) OR A/C CONDENSER FAN DRIVE 
CIRCUIT
Refer to P.14-6.
CIRCUIT OPERATION
Refer to P.14-6.
TECHNICAL DESCRIPTION
The cause could be a malfunction of the cooling fan 
motor (L.H.) or cooling fan motor drive control unit.
TROUBLESHOOTING HINTS
•Malfunction of cooling fan motor (L.H.)
•Malfunction of cooling fan motor drive control unit
DIAGNOSIS
STEP 1. Check the cooling fan motor (L.H.).
Refer to P.14-24.
Q: Is the cooling fan motor (L.H.) in good condition?
YES : Go to Step 2 .
NO : Replace the cooling fan motor (L.H.) (Refer 
to 
P.14-33) <4G1> (Refer to P.14-35) 
<4G6>. Then go to Step 3 .
STEP 2. Check the cooling fan motor drive 
control unit.
Refer to P.14-22.
Q: Is the cooling fan motor drive control unit in good 
condition?
YES : Go to Step 3 .
NO : Replace the cooling fan motor drive control 
unit (Refer to 
P.14-33) <4G1> (Refer to 
P.14-35) <4G6>. Then go to Step 3 .
STEP 3. Check the symptoms.
Q: Do the cooling fan (L.H.) operate (when the cooling 
fan (R.H.) <4G1> or A/C condenser fan <4G6> 
operate)?
YES : This symptoms is complete.
NO : Return to Step 1 . 
Page 36 of 800

AC200625
Cylinder block
drain plug
AC
ON-VEHICLE SER VICE
ENGINE COOLING14-22
5.App l y the designa ted sealant to  t he  scre w area of 
th e cylin der block drain plu g , and  then tighten  to 
th e st and ard torq ue.
Sp e c ified s ealant: 3 M  Nut Loc king Part 
No. 4171 o r  e quivale n t
Ti ghtenin g  torque:
40 ± 5 N⋅m <4G1>
44 ± 5 N⋅m <4G6>
6.Securely tighten t he drain plug of t he radiator .
7.Reinst all the ra diato r  con denser t ank.
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 compo
-
nents.
AC303612AB
MB991871
AIR HOSE
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 MEASUREMENT
M1141001100352
Measure the temperature and specific gravity of the 
engine coolant to check the antifreeze concentration.
Standard value: 30 − 60% (allowable concentra-
tion 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 concentra
-
tion 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
M1141006100250
1. Remove the cooling fan motor drive control unit  connector.
AC103195
Y1716AU
1
23
AC
Cooling fan motor
drive control unit
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