TROUBLESHOOTING
ENGINE COOLING14-12
STEP 15. 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 ondit i o n ?
YES : Go to S t ep 16 .
NO : Repa ir the con nect o r or rep l ace the re lay
box. Then
go to S t ep 24
.
STEP 16 . Check th e harness wire b e twee n fan
control relay
connect or A-09 X terminal 3 and
body ea
rth.
AC303510AB
Fan control relay
Relay boxConnector: A-09X
A-09X
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 1 7 . Check t he contin uity between cooling
fan motor drive
control un it connec tor A-1 8 and
body ea
rth.
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 .
AC303534AB
A-18 Connector
(Wiring harness side)
(2)M easu r e the re sist ance between cooling fan
mot o r d r ive cont rol unit conn ecto r A-1 8 te rmina l 1
and body earth .
•Continu i ty exist s .
(3)C onne ct cooling fa n mot o r drive control unit
connector A-18.
Q:Dos e the cont inuity e x ist s ?
YES : Go to S t ep 2 0 .
NO : Go to S t ep 18 .
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
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
.
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 .
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
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
.
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 .
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 .