TROUBLESHOOTING
ENGINE COOLING14-10
STEP 11. Measure the terminal voltage at fan
control relay connector A-09X.
AC303510AB
Fan control relay
Relay boxConnector: A-09X
A-09X
(1)D isconn ect f an co ntrol relay co nnector A-09X
(remove the fan control relay) and measure re lay
box side connector .
(2)T urn t he ig nition switch to the "ON" positio n.
AC303517AB
A-09X Connector
(Relay box side)
(3)M easu r e the volt age between fan control rela y
co nnector A-09X te rmin al 1 and bo dy ea rth.
•The voltage should measu r e syste m volt age.
(4)T urn t he ig nition switch to the "L OCK" (OFF )
position.
(5) C onne ct fa n con t rol re lay conn ecto r A-09X
(inst a ll the fan control relay).
Q:Is t h e mea s ure d volt ag e sy ste m v o lt ag e?
YES : Go to S t ep 14 .
NO : Go to S t ep 12 .
STEP 1 2 . Check t he J/C No.6 C-12
s > or C-134
intermedia
t e conne ctor A-13
s > C-1 1 1
control relay
connec tor A-0 9 X.
AC303524
Connector: C-12
AB
C-12
C-12
AC303525
Connector: C-134
AB
C-134
C-134
AC303526
Connector: A-13
AB
A-13
A-13
AC303527
Connector: C-111
AB
C-111
C-111
615121179
810234
AC303510AB
Fan control relay
Relay boxConnector: A-09X
A-09X
TROUBLESHOOTING
ENGINE COOLING14-11
Q: Are t h er e conn ect ors in go od cond it ion?
YES : Go to S t ep 13 .
NO : Repa ir or replace the conne ctor . Th en go to
S
t ep 24
.
STEP 1 3 . Check th e harness wire b e twee n J/C
No.
6 C-12 termina l 33
C-1
34 termina l 33
control relay
connect or A-09 X terminal 1 .
AC303524
Connector: C-12
AB
C-12
C-12
AC303525
Connector: C-134
AB
C-134
C-134
AC303510AB
Fan control relay
Relay boxConnector: A-09X
A-09X
Q:Are t h es e har n es s wires in go od cond it ion?
YES : An intermittent malf unction is suspe c ted
(Refer to GROUP 00 - How to use
troub leshooting
P.00-5).
NO : Repa ir the dama ged harness wire. Then go
to S
t ep 2 4
.
STEP 1 4 . Check t he contin uity between fan
control relay
connec tor A-0 9 X and bod y earth.
AC303510AB
Fan control relay
Relay boxConnector: A-09X
A-09X
(1)D isconn ect f an control relay co nnector A-09X
(remove the fan control relay) and measure re lay
box side connector .
AC303533AB
A-09X Connector
(Relay box side)
(2) M ea sure th e resi st anc e b e t w e e n f an con t rol re lay
connector A-09X te rmin al 3 and bo dy e a rth.
•Continu i ty exist s .
(3)C onne ct fa n con t rol re lay con necto r A-09X
(inst a ll the fan control relay).
Q:Doe s the cont inuity e x ist s ?
YES : An intermittent malf unction is suspe c ted
(Refer to GROUP 00 - How to use
troub leshooting
P.00-5).
NO : Go to S t ep 15 .
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
.