Page 801 of 1354
31
G
Position of Parts in Instrument Panel
E 3 Electronically Controlled Transmission Pattern J 9 Junction Connector
Select SW J 10 Junction Connector
E 4 Engine Control Module J 11 Junction Connector
E 5 Engine Control Module
E 6 Engine Control Module K 2 Key Interlock Solenoid
F 8 Fuse Block O 4 O/D Main SW
H 4 Hazard SW P 2 Parking Brake SW
I 10 Ignition SW R 3 Radio and Player
R 4 Radio and Player
J 1 Junction Connector R 5 Rear Window Defogger SW
J 2 Junction Connector R 6 Remote Control Mirror SW
J 3 Junction Connector R 7 Rheostat
J 4 Junction Connector
J 5 Junction Connector S 4 Shift Lock ECU
J 6 Junction Connector S 5 Stop Light SW
J 7 Junction Connector
J 8 Junction Connector U 1 Unlock Warning SW
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64
ENGINE CONTROL
THE ENGINE CONTROL SYSTEM UTILIZES A MICROCOMPUTER AND MAINTAINS OVERALL CONTROL OF THE ENGINE ETC. AN
OUTLINE OF ENGINE CONTROL IS GIVEN HERE.
1. INPUT SIGNALS
(1) ENGINE COOLANT TEMP. SENSOR SIGNAL SYSTEM
THE ENGINE COOLANT TEMP. SENSOR DETECTS THE ENGINE COOLANT TEMP. AND HAS A BUILT-IN THERMISTOR WITH A
RESISTANCE WHICH VARIES ACCORDING TO THE ENGINE COOLANT TEMP. THUS THE ENGINE COOLANT TEMP. IS INPUT IN
THE FORM OF A CONTROL SIGNAL TO TERMINAL THW OF THE ENGINE CONTROL MODULE.
(2) INTAKE AIR TEMP. SIGNAL SYSTEM
THE INTAKE AIR TEMP. SENSOR DETECTS THE INTAKE AIR TEMP. , WHICH IS INPUT AS A CONTROL SIGNAL TO TERMINAL THA
OF THE ENGINE CONTROL MODULE.
(3) OXYGEN SENSOR SIGNAL SYSTEM
THE OXYGEN SENSOR DETECTS THE OXYGEN DENSITY IN THE EXHAUST EMISSION WHICH IS INPUT AS A CONTROL SIGNAL
TO TERMINALS OX1 AND OX2 OF THE ENGINE CONTROL MODULE.
(4) THROTTLE SIGNAL SYSTEM
THE THROTTLE POSITION SENSOR DETECTS THE THROTTLE VALVE OPENING ANGLE, WHICH IS INPUT AS A CONTROL
SIGNAL TO TERMINAL VTA OF THE ENGINE CONTROL MODULE, OR WHEN THE VALVE IS FULLY CLOSED.
(5) VEHICLE SPEED CIRCUIT
THE VEHICLE SPEED IS DETECTED BY VEHICLE SPEED SENSOR INSTALLED IN THE TRANSMISSION AND THE SIGNAL IS INPUT
TO TERMINAL SPD OF THE ENGINE CONTROL MODULE VIA THE COMBINATION METER.
(6) PARK/NEUTRAL POSITION SW SIGNAL SYSTEM
THE PARK/NEUTRAL POSITION SW DETECTS WHETHER THE SHIFT POSITION IS IN NEUTRAL OR NOT, AND INPUTS A CONTROL
SIGNAL TO TERMINAL NSW OF THE ENGINE CONTROL MODULE.
(7) A/C SW SIGNAL SYSTEM
THE OPERATING VOLTAGE OF THE A/C MAGNETIC CLUTCH IS DETECTED AND INPUT IN THE FORM OF A CONTROL SIGNAL TO
TERMINAL ACI OF THE ENGINE CONTROL MODULE.
(8) BATTERY SIGNAL SYSTEM
VOLTAGE IS CONSTANTLY APPLIED TO TERMINAL BATT OF THE ENGINE CONTROL MODULE. WHEN THE IGNITION SW IS
TURNED TO ON, VOLTAGE FOR THE ENGINE CONTROL MODULE OPERATION IS APPLIED VIA THE EFI MAIN RELAY TO
TERMINAL +B OF THE ENGINE CONTROL MODULE.
(9) INTAKE AIR VOLUME SIGNAL SYSTEM
INTAKE AIR VOLUME IS DETECTED BY THE MANIFOLD ABSOLUTE PRESSURE SENSOR AND IS INPUT AS A CONTROL SIGNAL
TO TERMINAL PIN OF THE ENGINE CONTROL MODULE.
(10) STARTER SIGNAL SYSTEM
TO CONFIRM THAT THE ENGINE IS CRANKING, THE VOLTAGE APPLIED TO THE STARTER MOTOR DURING CRANKING IS
DETECTED AND IS INPUT AS A CONTROL SIGNAL TO TERMINAL STA OF THE ENGINE CONTROL MODULE.
(11) ELECTRICAL LOAD SIGNAL SYSTEM
THE SIGNAL WHEN SYSTEMS SUCH AS THE REAR WINDOW DEFOGGER, HEADLIGHT, ETC. WHICH CAUSE A HIGH ELECTRICAL
BURDEN ARE ON IS INPUT TO TERMINAL ELS AS A CONTROL SIGNAL.
SYSTEM OUTLINE
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130
ELECTRONICALLY CONTROLLED TRANSMISSION
THIS SYSTEM ELECTRONICALLY CONTROLS THE GEAR SHIFT TIMING, LOCK-UP TIMING, THE CLUTCH AND BRAKE HYDRAULIC
PRESSURE, AND THE ENGINE TORQUE DURING SHIFTING TO ACHIEVE OPTIMUM SHIFT FEELING.
IN ACCORDING TO THE VEHICLE DRIVING CONDITIONS AND ENGINE OPERATING CONDITIONS AS DETECTED BY VARIOUS
SENSORS.
1. GEAR SHIFT OPERATION
DURING DRIVING, THE ENGINE CONTROL MODULE SELECTS THE SHIFT FOR EACH GEAR WHICH IS MOST APPROPRIATE TO THE
DRIVING CONDITIONS, BASED ON INPUT SIGNALS FROM THE ENGINE COOLANT TEMP. SENSOR TO TERMINAL THW OF THE
ENGINE CONTROL MODULE, AND ALSO THE INPUT SIGNALS TO TERMINAL SPD OF THE ENGINE CONTROL MODULE FROM THE
SPEEDOMETER DEVOTED TO THE ELECTRONICALLY CONTROLLED TRANSMISSION. CURRENT IS THEN OUTPUT TO THE
ELECTRONICALLY CONTROLLED TRANSMISSION SOLENOID. WHEN SHIFTING TO 1ST SPEED, CURRENT FLOWS FROM TERMINAL
S1 OF THE ENGINE CONTROL MODULE "TERMINAL
(A) 3 (2WD) OR (B) 3 (4WD) OF THE ELECTRONICALLY CONTROLLED
TRANSMISSION SOLENOID "GROUND, AND CONTINUES TO THE NO. 1 SOLENOID CAUSES THE SHIFT.
FOR 2ND SPEED, CURRENT FLOWS FROM TERMINAL S1 OF THE ENGINE CONTROL MODULE "TERMINAL 3 OF THE
ELECTRONICALLY CONTROLLED TRANSMISSION SOLENOID "GROUND, AND FROM TERMINAL S2 OF THE ENGINE CONTROL
MODULE "TERMINAL
(A) 1 (2WD) OR (B) 6 (4WD) OF THE ELECTRONICALLY CONTROLLED TRANSMISSION SOLENOID "
GROUND, AND CONTINUES TO SOLENOIDS NO. 1 AND NO. 2 CAUSES THE SHIFT.
FOR 3RD SPEED, THERE IS NO CONTINUOUS TO NO. 1 SOLENOID, ONLY TO NO. 2 CAUSING THE SHIFT.
SHIFTING INTO 4TH SPEED (OVERDRIVE) TAKES PLACE WHEN THERE IS NO CONTINUOUS TO EITHER NO. 1 OR NO. 2 SOLENOID.
2. LOCK-UP OPERATION
WHEN THE ENGINE CONTROL MODULE JUDGES FROM EACH SIGNAL THAT LOCK-UP OPERATION CONDITIONS HAVE BEEN MET,
CURRENT FLOWS FROM TERMINAL SL OF THE ENGINE CONTROL MODULE "TERMINAL
(A) 2 (2WD) OR (B) 5 (4WD) OF THE
ELECTRONICALLY CONTROLLED TRANSMISSION SOLENOID "GROUND, CONTINUES TO THE LOCK-UP SOLENOID AND CAUSING
LOCK-UP OPERATION.
3. STOP LIGHT SW CIRCUIT
IF THE BRAKE PEDAL IS DEPRESSED (STOP LIGHT SW ON) WHEN DRIVING IN LOCK-UP CONDITION, A SIGNAL IS INPUT TO
TERMINAL B/K OF THE ENGINE CONTROL MODULE, THE ENGINE CONTROL MODULE OPERATES AND CURRENT TO THE LOCK-UP
SOLENOID IS CUT.
4. OVERDRIVE CIRCUIT
*O/D MAIN SW ON
WHEN THE O/D MAIN SW IS TURNED ON (SW POINT IS OPEN), A SIGNAL IS INPUT TO TERMINAL OD2 OF THE ENGINE CONTROL
MODULE AND ENGINE CONTROL MODULE OPERATION CAUSES GEAR SHIFT WHEN THE CONDITIONS FOR OVERDRIVE ARE MET.
*O/D MAIN SW OFF
WHEN THE O/D MAIN SW IS TURNED OFF (SW POINT IS CLOSED), THE CURRENT FLOWING THROUGH THE O/D OFF INDICATOR
LIGHT FLOWS THROUGH THE O/D MAIN SW TO GROUND. CAUSING THE INDICATOR LIGHT TO LIGHT UP. AT THE SAME TIME, A
SIGNAL IS INPUT TO TERMINAL OD2 OF THE ENGINE CONTROL MODULE AND ENGINE CONTROL MODULE OPERATION
PREVENTS SHIFT INTO OVERDRIVE.
SYSTEM OUTLINE
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131
5. CENTER DIFFERENTIAL CLUTCH CONTROL (4WD)
THE CENTER DIFFERENTIAL CLUTCH CONTROL USES A LINEAR SOLENOID TYPE VALVE (SOLENOID VALVE SLD) TO CONTROL THE
CENTER DIFFERENTIAL CLUTCH. BY CONTROLLING THE FLUID PRESSURE, THE LIMITED SLIP DIFFERENTIAL EFFECT OF THE
CENTER DIFFERENTIAL CAN ALWAYS BE MAINTAINED AT THE OPTIMUM FOR THE CURRENT DRIVING CONDITIONS TO INCREASE
ROAD-HOLDING ABILITY.
SOLENOID VALVE SLD OPENS AND CLOSES IN RESPONSE TO SIGNALS FROM THE ENGINE CONTROL MODULE. THUS THE
SOLENOID MODULATOR VALVE MAINTAINS A CONSTANT FLUID PRESSURE FOR OPERATION OF THE CENTER DIFFERENTIAL
CLUTCH CONTROL VALVE AND CENTER DIFFERENTIAL CLUTCH.
*NORMAL DRIVING
SOLENOID VALVE SLD OPENS AND CLOSES IN RESPONSE TO THE THROTTLE OPENING ANGLE TO CONTROL THE FLUID
PRESSURE OPERATING ON THE CENTER DIFFERENTIAL CLUTCH. WHEN THE VEHICLE TAKES OFF IN FIRST GEAR WITH A
LARGE THROTTLE OPENING ANGLE, THE FLUID PRESSURE IS KEPT HIGH. SO EVEN IF THE VEHICLE TAKES OFF SUDDENLY OR
THE ROAD SURFACE IS SLIPPERY, SMOOTH, RELIABLE ACCELERATION IS POSSIBLE.
*SLIPPING
WHEN A LARGE DIFFERENCE OCCURS BETWEEN THE FRONT WHEEL SPEED AND REAR WHEEL SPEED AT LOW SPEEDS,
SOLENOID VALVE SLD IS FULLY CLOSED TO APPLY HIGH FLUID PRESSURE TO THE CENTER DIFFERENTIAL CLUTCH AND
PROVIDE A LARGE LIMITED SLIP DIFFERENTIAL EFFECT.
*WIDE CORNERING
WHEN DIFFERENCES ARISE BETWEEN THE FRONT WHEEL SPEED AND REAR WHEEL SPEED DUE TO DIFFERENCES IN THE
TURNING RADIUS DURING CORNERING AT LOW SPEEDS, SOLENOID VALVE SLD IS FULLY OPEN TO APPLY A WEAK LIMITED SLIP
DIFFERENTIAL EFFECT AND PERMIT SMOOTH CORNERING.
6. ELECTRONICALLY CONTROLLED TRANSMISSION PATTERN SELECT SW
IF THE ELECTRONICALLY CONTROLLED TRANSMISSION PATTERN SELECT SW IS CHANGED FROM NORMAL TO POWER, THE
CURRENT THROUGH THE POWER INDICATOR FLOWS TO GROUND, CURRENT FLOWS TO TERMINAL P OF THE ENGINE CONTROL
MODULE, THE ENGINE CONTROL MODULE OPERATES, AND SHIFT UP AND SHIFT DOWN OCCURS AT HIGHER VEHICLE SPEEDS
THAN WHEN THE SW IS IN NORMAL POSITION.
Page 901 of 1354
132
ELECTRONICALLY CONTROLLED TRANSMISSION
EA1 7IG 1 11
21215A
EFI
2 PAGE 54)
25 1366
66IB 2 20
P
N
EA12
EAC 22 C1C4
C 11 C12 STA +B NSW BATT B/K
ENGINE CONTROL MODULEB E 4 , E 5AC, E 6 17 16
B-R B-R
B-R B-R B-R
R-W B-W
B-W
R-WR-WB-O
PARK/NEUTRAL
POSITION SW
EFI
MAIN
REL AY
R- W
G-W
FROM STOP LIGHT SW
BATTERYI 4 B 5(
4WD) A 2(
2WD)
A 3(
2W D)
B 6(
4W D) IG 1 10
B P 1 , A
TO ST RELAYE 1
AM 1ACC
IG 1
11
B-W B-W
IG NITION SW I1 0
B-O
A AA
B-W
B-W JU NC TIO N
CONNECTOR J 5
7
8 AM 2 IG2
ST2
IG 1 9 20A
AM 2
2 20
A
J 1
JU NC TIO N
CONNECTOR
A
B-R
B-R B-RW
B W-B
BLE
BLOCK
W-B
2I 5IG 1 12C C
JUNCTION
CONNECT J 5
B B
B
B
EA1 9
B
1H13
1D3
1E 1
1J 2
OR
80A M A IN
FUSI
LIN K F 7
FROM POW ER SOURCE SYSTEM (
SEE
7. 5A IGN
[FUSE BLO CK] 10
F 8
Page 903 of 1354
134
ELECTRONICALLY CONTROLLED TRANSMISSION
GAUGE
SE BLOCK] FROM POW ER SOURCE SYSTEM (
SEE PAGE 54)
IG 1 2 IG 2 9 IG 2 10
EC IGA 8
A 5A4A2 A 10 A11 B2
ECT PW RO/D OFF
4
R-G
LG
R-L
R- B LG-LG BR BR BR
R-L R-LR-L
R-LR-L-L
-L
LG
R-G LG
R-G
-W
V-WR- Y
L- B R- Y
L-B
W-B LG W-B
CO MBINATION M ETERB C 9 , C10A
EL ECTRONICALLY
CONTROLLED TRANSM ISSION
PATTERN SELECT SW E 3
(
COM BINATION METER) SPEED
JUNC
CONN J 32
CTION
NECTORB , J1 1 A
W-B JUNCTION CONNECTORB J10 , J11A
B BBBA C A C
I 5
1E 81B8
R
R
10A
[FU 3
F 8
POW ER NORMAL
3
BB B
B
TION
ECTORB
B JUN CTIO N
CONNECTOR J 5
C 7
OD2C 15
PC 9
SPD
C 8R
C 182
C 19L
A 14E1
A 26E02
A 13E01321
R
V
W-B
ENGINE CONTRO L M ODULEB E 4 , E 5AC, E 6
VEHICLE SPEED SENSOR V 2
IG 2 15 IG 216 IG17
4 2
A A
R-B LG - RLG BR BR BR
R-L
W-B
JUN CTION
CONNECTOR J 2O/D MAIN SW O 4
B A B 8(
4WD) A 5(
2WD)
B 3A 9
B 4A 4
A AAA A 6(
2WD)
B 2(
4WD)JU N
CON J10W-B
B P 1 , A
PARK/NEUTRAL
POSITION
SW
Page 905 of 1354
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ELECTRONICALLY CONTROLLED TRANSMISSION
Page 915 of 1354
146
CRUISE CONTROL
I 7
I 5
I1 1
I 8 A C
B BBBIG 1 2
IG 2 9IG210IG 1 5
IG 1 12
IGIG R-L
R- R-L
(
M/T)
R-L
R-L
R-L
R-L R-L
(
M/T)
(
A/T) R- L
(
A/T) B-W
(
A/T) BR
G-R
L-B
R-Y
V-W
R-L
(
M/T)
R-L
(
A/T)
R-YL-B BR
VEHICLE SPEED SENSOR
(
COMBINATIO N METER)J1 0
P
(
A/T) V-W
V-W
Y-B
(
A/T)
G- R
W-BV-W
W-BB- W
(
A/T)
B-W
(
M/T)
LL
B-W
(
A/T)CRUISE CONTROL
CLUTCH SW C15
FR O M THR O TTLE P O SITIO N
SENSOR
FROM POW ER SOURCE SYSTEM (
SEE PAGE 54)
E
CK]
JUNCTION
CONNECTORB J10 , J11A
B P 1 , A
PARK/NEUTRAL POSITION SW
IG 1 6
I 5
B 6B9B20 A15
SPD DOD1S2
ENGINE CONTROL MODULEB E 4 , E 6A
P
(
A/T) P
(
A/T) P
(
A/T)
TO ELECTRONICALLY
CONTROLLED TRANSMISSION
SOLENOID
B 2(
4W D) A 6(
2W D)
A 8(
2W D)
B 10(
4W D)
B-W
(
A/T)
43
R
-L
10A GAUG
[FUS E B LO F 8
1
CO M BINA TIO N M ETER C 9
CRUISE
SPEED
12 6 11 10 28
21 2
13 7 9 20CRUISE CONTROL ECU C16
22 DIDL
SPDODECT PI GND
213
V 2
A
A
JU NC TIO N
CONNECTORL
1E 8
1B 8