
CO(H6DO)-8
Radiator Fan System
COOLING
B: RADIATOR FAN CONTROL OUTPUT WAVEFORM
C: INSPECTION
DETECTING CONDITION:
•Engine coolant temperature is more than 95°C (203°F).
•A/C switch is turned OFF.
•Vehicle speed is below 19 km/h (12 MPH).
TROUBLE SYMPTOMS:
Radiator main fan and sub fan do not rotate under the above conditions.
(A) 5 V
Step Check Yes No
1CHECK MAIN FAN RELAY 1.
1) Turn the ignition switch to OFF.
2) Remove the main fan relay 1 from A/C relay
holder.
3) Measure the resistance of terminal in main
fan relay 1 switch.
Is the resistance more than 1
MΩ?
Go to step 2.Replace the main
fan relay 1.
2CHECK MAIN FAN RELAY 1.
1) Connect the battery to terminal of main fan
relay 1 coil.
2) Measure the resistance between terminals
of main fan relay 1 switch.
Is the resistance less than 1
Ω?
Go to step 3.Replace the main
fan relay 1.
3CHECK POWER SUPPLY FOR ECM.
1) Turn the ignition switch to OFF.
2) Disconnect the connectors from the ECM.
3) Turn the ignition switch ON.
4) Measure the voltage between ECM termi-
nal and chassis ground.
Connector & terminal
(B136) No. 29 (+) — Chassis ground (–):
Is the voltage more than 10 V? Go to step 4.Repair the power
supply line.
CO-02117
(V)
0
(A)

CO(H6DO)-9
Radiator Fan System
COOLING
4CHECK POWER SUPPLY FOR RADIATOR
FAN CONTROL UNIT.
1) Turn the ignition switch to OFF.
2) Connect the connector to ECM.
3) Disconnect the connector from radiator fan
control unit.
4) Turn the ignition switch ON.
5) Measure the voltage between radiator fan
control unit terminal and chassis ground.
Connector & terminal
(F106) No. 3 (+) — Chassis ground (–):
Is the voltage more than 10 V? Go to step 5.Repair the power
supply line.
5CHECK HARNESS BETWEEN ECM AND RA-
DIATOR FAN CONTROL UNIT.
1) Turn the ignition switch to OFF.
2) Disconnect the connectors from the ECM.
3) Measure the resistance between radiator
fan control unit and ECM connector.
Connector & terminal
(B136) No. 18 — (F106) No. 2:
Is the resistance less than 1
Ω?
Go to step 6.Repair the open
circuit of harness
between ECM and
radiator fan con-
trol unit.
6CHECK RADIATOR FAN CONTROL UNIT
AND GROUND CIRCUIT.
1) Connect the connector to ECM and radiator
fan control unit.
2) Measure the resistance between radiator
fan control unit connector and chassis ground.
Connector & terminal
(F106) No. 1 — Chassis ground:
Is the resistance less than 5
Ω?
Go to step 7.Repair the open
circuit of harness
between radiator
fan control unit
connector and
chassis ground.
7CHECK MAIN FAN MOTOR.
1) Disconnect the connector from radiator fan
control unit.
2) Connect the battery positive (+) terminal to
terminal No. 1 of the main fan motor, and the
ground (–) terminal to terminal No. 2.
Does the main fan motor
rotate?
Go to step 8.Replace the main
fan motor.
8CHECK SUB FAN MOTOR.
1) Disconnect the connector from radiator fan
control unit.
2) Connect the battery positive (+) terminal to
terminal No. 1 of the sub fan motor, and the
ground (–) terminal to terminal No. 2.
Does the sub fan motor rotate? Go to step 9.Replace the sub
fan motor.
9CHECK OUTPUT SIGNAL FROM ECM.
1) Turn the ignition switch to OFF.
2) Connect the test mode connector.
3) Turn the ignition switch ON.
4) Check the output waveform using oscillo-
scope.
Fa n S y st e m. >
Connector & terminal
(B134) No. 18 (+) — Chassis ground (–):
Is waveform being output? Replace the radia-
tor fan control unit.
Radiator Fan Con-
trol Unit.>
Replace the ECM.
Engine Control
Module (ECM).>
Step Check Yes No

EN(H6DO)(diag)-16
Engine Control Module (ECM) I/O Signal
ENGINE (DIAGNOSTICS)
5. Engine Control Module (ECM) I/O Signal
A: ELECTRICAL SPECIFICATION
DescriptionConnector
No.
Te r m i n a l
No.
Signal (V)
ReferenceIgnition SW ON
(engine OFF)
Engine ON
(idling)
Crankshaft Position
Sensor
Signal (+) B134 13 0 –7 — +7 Waveform
Signal (–) B134 14 0 0 —
Shield B134 24 0 0 —
Camshaft position sensor (LH) B134 11 0.275 0 or 5 Waveform
Camshaft position sensor (RH) B134 21 0.275 0 or 5 Waveform
Camshaft position sensor
(ground)B134 22 0 0 —
Electronic throttle
control
Main B134 180.64 — 0.94
Fully opened: 4.01
0.64 — 0.72
(After engine is
warmed-up.)
Fully closed: 0.6
Fully opened: 4.01
Sub B134 281.51 — 1.76
Fully opened: 4.23
1.51 — 1.58
(After engine is
warmed-up.)
Fully closed: 1.48
Fully opened: 4.23
Electronic throttle control motor
(+)B137 5 Duty waveform Duty waveformDrive frequency: 500
Hz
Electronic throttle control motor (–) B137 4 Duty waveform Duty waveformDrive frequency: 500
Hz
Electronic throttle control motor
power supplyB136 1 10 — 13 12 — 14 —
Electronic throttle control motor
relayB136 21ON: 0
OFF: 10 — 13
ON: 0
OFF: 13 — 14
When ignition switch
is turned to ON: ON
Accelerator pedal
position sensor
Main B135 23Fully closed: 0.7
Fully opened: 3.5
Fully closed: 0.7
Fully opened: 3.5—
Powe r s up -
ply (main)B135 21 5 5 —
Ground
(main)B135 29 0 0 —
Sub B135 31Fully closed: 0.7
Fully opened: 3.5
Fully closed: 0.7
Fully opened: 3.5—
Engine coolant temperature sen-
sorB134 34 1.0 — 1.4 1.0 — 1.4After engine is
warmed-up.
EN-01812
B134
5678219431024 2223251112131415262728
1617181920213334 2932 3031
B136
5678219431024 2223251112131415262728
16171819202133342932303135
B135
5678219431024 2223251112131415262728
16171819202129303132333435
B137
5678219431022231112131415242526
1617181920212728293031
ToToToTo

EN(H6DO)(diag)-17
Engine Control Module (ECM) I/O Signal
ENGINE (DIAGNOSTICS)
Starter switch B136 32 0 0 Cranking: 8 — 14
Starter relay B136 20ON: 0
OFF: 10 — 13
ON: 0
OFF: 13 — 14—
A/C switch B136 24ON: 10 — 13
OFF: 0
ON: 13 — 14
OFF: 0—
A/C middle pressure switch B136 33ON: 0
OFF: 10 — 13
ON: 0
OFF: 13 — 14—
Ignition switch B135 19 10 — 13 13 — 14 —
Neutral position switch B136 31ON: 0
OFF: 12±0.5
Switch is ON when
select lever is shifted
into “P” or “N” range.
Te s t m o d e c o n n e c t o r B 1 3 5 2 7 1 0 — 1 3 1 2 — 1 4 W h e n c o n n e c t e d : 0
Knock sensor 1Signal B134 15 2.4 2.4 —
Shield B134 25 0 0 —
Knock sensor 2Signal B134 16 2.4 2.4 —
Shield B134 25 0 0 —
Back-up power supply B135 5 10 — 13 13 — 14Ignition switch
“OFF”: 10 — 13
Control module power supplyB134 7 10 — 13 13 — 14 —
B135 2 10 — 13 13 — 14 —
Sensor power supply (engine
side)B134 19 5 5 —
Sensor ground (engine side) B134 29 0 0 —
Sensor power supply (body side) B135 22 5 5 —
Sensor ground (body side) B135 30 0 0 —
Ignition control
#1 B137 18 0 1 — 14 Waveform
#2 B137 19 0 1 — 14 Waveform
#3 B137 20 0 1 — 14 Waveform
#4 B137 21 0 1 — 14 Waveform
#5 B137 22 0 1 — 14 Waveform
#6 B137 23 0 1 — 14 Waveform
Fuel Injector
#1 B137 8 10 — 13 1 — 14 Waveform
#2 B137 9 10 — 13 1 — 14 Waveform
#3 B137 10 10 — 13 1 — 14 Waveform
#4 B137 11 10 — 13 1 — 14 Waveform
#5 B137 12 10 — 13 1 — 14 Waveform
#6 B137 13 10 — 13 1 — 14 Waveform
A/C relay control B136 9ON: 0.5 or less
OFF: 10 — 13
ON: 0.5 or less
OFF: 13 — 14—
Radiator fan control B136 18ON: 0.5 or less
OFF: 10 — 13
ON: 0.5 or less
OFF: 13 — 14—
Radiator fan control power supply B136 29ON: 0.5 or less
OFF: 10 — 13
ON: 0.5 or less
OFF: 13 — 14—
Self-shutoff control B136 23 0 0 —
Malfunction indicator light B136 11 — —Light: 1 or less
Extinguish: 10 — 14
Engine speed output B136 22 — 0 — 13 or more Waveform
Purge control solenoid valve B137 29ON: 1 or less
OFF: 10 — 13
ON: 1 or less
OFF: 13 — 14—
Pow er s te e r in g sw it c h B 1 3 4 33ON: 1 or less
OFF: 10 — 13
ON: 1 or less
OFF: 13 — 14—
DescriptionConnector
No.
Te r m i n a l
No.
Signal (V)
ReferenceIgnition SW ON
(engine OFF)
Engine ON
(idling)

EN(H6DO)(diag)-18
Engine Control Module (ECM) I/O Signal
ENGINE (DIAGNOSTICS)
Manifold absolute pressure sen-
sorB134 6 3.5 — 4.8 1.1 — 1.9 —
Air flow sensor
Signal B135 26 0.74 0.3 — 4.5 —
Shield B135 35 0 0 —
Ground B135 34 0 0 —
Intake air temperature sensor B135 18 3.15 — 3.33 3.15 — 3.33Intake air tempera-
ture 25°C (75°F)
Fr o nt ox yg e n ( A / F)
sensor RH
Signal (+) B135 9 2.8 — 3.2 2.8 — 3.2 —
Signal (–) B135 8 2.4 — 2.7 2.4 — 2.7 —
Shield B135 1 0 0 —
Fr o nt ox yg e n ( A / F)
sensor heater RH
Signal 1 B136 3 12 — 14 — Waveform
Signal 2 B136 2 12 — 14 — Waveform
Fr o nt ox yg e n ( A / F)
sensor LH
Signal (+) B135 11 2.8 — 3.2 2.8 — 3.2 —
Signal (–) B135 10 2.4 — 2.7 2.4 — 2.7 —
Shield B135 1 0 0 —
Fr o nt ox yg e n ( A / F)
sensor heater LH
Signal 1 B135 7 12 — 14 — Waveform
Signal 2 B135 6 12 — 14 — Waveform
Rear oxygen sen-
sor RH
Signal B135 4 0 0 — 0.9 —
Shield B135 1 0 0 —
Rear oxygen sensor heater RH
signalB136 4 12 — 14 — Waveform
Rear oxygen sen-
sor LH
Signal B135 15 0 0 — 0.9 —
Shield B135 1 0 0 —
Rear oxygen sensor heater LH
signalB136 5 12 — 14 — Waveform
Immobilizer communication 1 B136 26 10 10 —
Immobilizer communication 2 B136 34 10 10 —
Fuel pump control
unit
Diagnosis
signalB135 33 10 — 13 13 — 14 —
Control B136 12 0 0 or 5 —
Brake switch 1 B135 20
When brake pedal is
depressed: 0
When brake pedal is
released: 10 — 13
When brake pedal is
depressed: 0
When brake pedal is
released: 13 — 14
—
Brake switch 2 B135 28
When brake pedal is
depressed: 10 — 13
When brake pedal is
released: 0
When brake pedal is
depressed: 13 — 14
When brake pedal is
released: 0
—
Cruise control command switch B135 24
When operating
nothing: 3.5 — 4.5
When operating
RES/ACC: 2.5 — 3.5
When operating SET/
COAST: 0.5 — 1.5
When operating
CANCEL: 0 — 0.5
When operating
nothing: 3.5 — 4.5
When operating
RES/ACC: 2.5 — 3.5
When operating SET/
COAST: 0.5 — 1.5
When operating
CANCEL: 0 — 0.5
—
Cruise control main switch B135 12ON: 0
OFF: 5
ON: 0
OFF: 5—
Oil flow control sole-
noid valve RH
Signal (+) B137 17 0 0.6 —
Signal (–) B137 16 0 0 —
Oil flow control sole-
noid valve LH
Signal (+) B137 15 0 0.6 —
Signal (–) B137 14 0 0 —
DescriptionConnector
No.
Te r m i n a l
No.
Signal (V)
ReferenceIgnition SW ON
(engine OFF)
Engine ON
(idling)

EN(H6DO)(diag)-19
Engine Control Module (ECM) I/O Signal
ENGINE (DIAGNOSTICS)
Oil switching sole-
noid valve RH
Signal (+) B137 25 0 1.9 —
Signal (–) B137 24 0 0 —
Oil switching sole-
noid valve LH
Signal (+) B137 31 0 1.9 —
Signal (–) B137 30 0 0 —
Oil temperature sensor signal B134 23 1.0 — 1.4 1.0 — 1.4After engine is
warmed-up.
Va r i a b l e va l v e l i f t d i a g n o s i s o i l
pressure switch RHB134 31 0 0 —
Va r i a b l e va l v e l i f t d i a g n o s i s o i l
pressure switch LHB134 32 0 0 —
Generator control B136 10 0 — 6.5 0 — 6.5 —
SSM communication B136 161 or less ←→ 4 or
more
1 or less ←→ 4 or
more—
Fuel tank pressure sensor B135 32 2.3 2.7 —
Drain valve B136 17ON: 1 or less
OFF: 10 — 13
ON: 1 or less
OFF: 13 — 14—
Fuel temperature sensor B135 17 2.5 — 3.8 2.5 — 3.8Ambient tempera-
ture: 25°C (75°F)
CAN communication line (+) B136 27More than 2.0 ←→
Less than 4.5
More than 2.0 ←→
Less than 4.5—
CAN communication (–) B136 35More than 0.5 ←→
Less than 3.0
More than 0.5 ←→
Less than 3.0—
Ground (injector system 1) B137 26 0 0 —
Ground (injector system 2) B137 6 0 0 —
Ground (engine 1) B134 5 0 0 —
Ground (engine 2) B137 7 0 0 —
Ground (engine 3) B137 2 0 0 —
Ground (engine 4) B137 1 0 0 —
Ground (engine 5) B137 3 0 0 —
Ground (engine 6) B134 3 0 0 —
Ground (body) B136 6 0 0 —
DescriptionConnector
No.
Te r m i n a l
No.
Signal (V)
ReferenceIgnition SW ON
(engine OFF)
Engine ON
(idling)

EN(H6DO)(diag)-50
Malfunction Indicator Light
ENGINE (DIAGNOSTICS)
C: MALFUNCTION INDICATOR LIGHT DOES NOT COME ON
DIAGNOSIS:
The malfunction indicator light circuit is open or shorted.
TROUBLE SYMPTOM:
When the ignition switch is turned to ON (engine OFF), malfunction indicator light does not come on.
WIRING DIAGRAM:
EN-03733
3
B72
i3
B38
B136
SBF-66
11
A4
7
MAIN SBFNO.5
B11
E
A3
B72
134562
B38
1234 5678910 11 12 13 14 15 16 17 18 19 20
ECM
COMBINATIONMETER
IGNITIONSWITCHBATTERY
i126
i1271*1*
2*
i10A:
i11B:
i127
i126
123456789101112
1234567891011121314
i11B:
123456789101112131415161718192021222324252627282930
i10A:
2* : TERMINAL NO. OPTIONAL ARRANGEMENT AMONG 10, 11 AND 12
1* : TERMINAL NO. OPTIONAL ARRANGEMENT AMONG 7, 8 AND 9
B136
16101112131415252430
9871718192028212223293231
123456
2726333435
Step Check Yes No
1CHECK OUTPUT SIGNAL OF ECM.
1) Turn the ignition switch to ON.
2) Measure the voltage between ECM con-
nector and chassis ground.
Connector & terminal
(B136) No. 11 (+) — Chassis ground (–):
Is the voltage less than 1 V? Go to step 4.Go to step 2.
2CHECK POOR CONTACT.
Check for poor connection by shaking or pull-
ing ECM connector and harness.
Does the malfunction indicator
light illuminate?
Repair poor con-
tact in ECM con-
nector.
Go to step 3.

EN(H6DO)(diag)-51
Malfunction Indicator Light
ENGINE (DIAGNOSTICS)
3CHECK ECM CONNECTOR.
Check the connection of ECM connector.
Is the ECM connector correctly
connected?
Replace the ECM.
Engine Control
Module (ECM).>
Repair the con-
nection of ECM
connector.
4CHECK HARNESS BETWEEN COMBINA-
TION METER AND ECM CONNECTOR.
1) Turn the ignition switch to OFF.
2) Remove the combination meter.
3) Disconnect the connector from ECM and
combination meter.
4) Measure the resistance of harness
between ECM and combination meter connec-
tor.
Connector & terminal
(B136) No. 11 — (i11) No. 11:
Is the resistance less than 1
Ω?
Go to step 5.Repair the har-
ness and connec-
tor.
NOTE:In this case, repair
the following item:
•Open circuit
of harness be-
tween ECM and
combination
meter connec-
tor
•Poor contact
of coupling con-
nector
5CHECK POOR CONTACT.
Check poor contact of combination meter con-
nector.
Is there poor contact in combi-
nation meter connector?
Repair the poor
contact of combi-
nation meter con-
nector.
Go to step 6.
6CHECK HARNESS BETWEEN COMBINA-
TION METER AND IGNITION SWITCH CON-
NECTOR.
1) Turn the ignition switch to ON.
2) Measure the voltage between combination
meter connector and chassis ground.
Connector & terminal
(i10) No. 3 (+) — Chassis ground (–):
(i10) No. 4 (+) — Chassis ground (–):
Is the voltage more than 10 V? Replace the com-
bination meter
board.
tion Meter.>
Check the follow-
ing item and repair
if necessary.
NOTE:
•Blown out of
fuse (No. 5)
•Open or short
circuit of har-
ness between
fuse (No. 5) and
battery terminal
•Poor contact
of ignition
switch connec-
tor
Step Check Yes No