ECU LEXUS SC400 1991 Service Repair Manual

11 9
1K
7
15 14 11 7 3 4 16 8
2 1 4 4
IP17
IF2 7
I2 I8
I11
I11IF
IF2
16 IF2 18 IP1 6IP118
4 1 M
5
2
4
1 M
5
2
UL1 L1 LSWD LSWP ACT± ACT+ E
P±B
L±W
P±B
W±L
G±W
G±Y
L±W
W±B
W±B L±R
L±R
L±W
G±W
G±Y
W±L
P±B
L±W
L±R
W±B
L±W
L±W
L±W
P±B
L±W
W±B
L±R L±R W±L
L±R
W±B
FROM POWER SOURCE SYSTEM (
SEE PAGE 56 )
30A
DOOR
+B2
THEFT DETERRENT AND DOOR LOCK ECU
L±W
L±W
P±B
L±W
DOOR LOCK MOTOR,
DOOR UNLOCK DETECTION SW AND
DOOR OPEN DETECTION SW LH
DOOR LOCK MOTOR,
DOOR UNLOCK DETECTION SW AND
DOOR OPEN DETECTION SW RH
DIODE
D10
D11
T9 6 5
I15
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120
WIRELESS DOOR LOCK REMOTE CONTROL
DOOR LOCK CONTROL (LOCK AND UNLOCK) IS PERFORMED BY REMOTE CONTROL, WI\
THOUT THE IGNITION KEY INSERTED IN
THE DOOR KEY CYLINDER, USING LOW±POWER RADIO WAVES EMITTED BY A TRANSMITTER BUILT INTO IGNITION KEY.
1. WIRELESS DOOR LOCK OR UNLOCK NORMAL OPERATION
WITH THE WIRELESS DOOR LOCK MAIN SW ON, THE IGNITION KEY NOT INSERTED INTO THE IGNITION KEY CYLINDER (UNLOCK
WARNING SW OFF) AND ALL THE DOORS COMPLETELY CLOSED, WHEN THE SWITCH (TRANSMITTER) ON THE IGNITION KEY IS
PUSHED, THE WIRELESS DOOR LOCK ECU RECEIVES THE ELECTRICAL WAVES FROM THE IGNITION KEY (TRANSMITTER),
CAUSING IT TO OPERATE.
AS A RESULT, THE ECU JUDGES WHETHER THE DOOR IS LOCKED OR UNLOCKED BASED ON THE SIGNAL FROM THE DOOR LOCK
MOTOR, AND SENDS A SIGNAL TO THE DOOR LOCK ECU TO SWITCH THE CONDITION FROM LOCK TO UNLOCK OR VICE VERSA,
CAUSING THE DOOR LOCK MOTOR TO OPERATE (FOR THE CURRENT FLOW DURING LOCK AND UNLOCK REFER TO THE DOOR
LOCK CONTROL SYSTEM.)
2. AUTO LOCK OPERATION
AFTER PUSHING THE IGNITION KEY SWITCH (TRANSMITTER) TO UNLOCK ALL THE DOORS, IF A DOOR IS NOT OPENED WITHIN 30
SECONDS, ALL OF THE DOORS ARE AUTOMATICALLY LOCKED AGAIN.
3. WIRELESS DOOR LOCK STOP FUNCTION
IF A DOOR IS OPEN (DOOR COURTESY SW ON), A SIGNAL IS INPUT FROM THE DOOR OPEN COURTESY SW TO THE WIRELESS
DOOR LOCK ECU, STOPPING WIRELESS DOOR LOCK OR UNLOCK.
IF THE IGNITION KEY IS IN THE IGNITION KEY CYLINDER (UNLOCK WARNING SW ON), THE UNLOCK WARNING SWITCH INPUT A
SIGNAL TO THE WIRELESS DOOR LOCK ECU, STOPPING WIRELESS DOOR LOCK OR UNLOCK.
4. DOOR LOCK MOTOR PROTECTIVE FUNCTION
IF THE DOOR LOCK OR UNLOCK CONDITION DOES NOT CHANGE AFTER WIRELESS DOOR L\
OCK OR UNLOCK OPERATION, THE
DOOR LOCK ECU SENDS CURRENT TEN TIMES TO THE DOOR LOCK MOTOR. IF THE DOOR LOCK CONDITION STILL HAS NOT
CHANGED AS A RESULT THE WIRELESS DOOR LOCK ECU STOPS RECEPTION AND STOPS DOOR LOCK AND UNLOCK FUNCTION.
BY MANUALLY OPERATION THE DOOR LOCK OR UNLOCK, THE STOP CONDITION OF THE WIRELESS DOOR LOCK FUNCTION IS
RELEASED.
D10, D11 DOOR OPEN DETECTION SW LH, RH
3±6 : CLOSED WITH DOOR OPENED
I15 UNLOCK WARNING SW [IGNITION SW]
10±9 : CLOSED WITH IGNITION KEY IN CYLINDER
W 8 WIRELESS DOOR LOCK ECU
1±GROUND: APPROX. 12 VOLTS WITH WIRELESS DOOR LOCK MAIN SW ON
7±GROUND: ALWAYS CONTINUITY
10±GROUND: CONTINUITY WITH EACH DOOR OPENED
6±GROUND: CONTINUITY WITH IGNITION KEY IN CYLINDER
: PARTS LOCATION
CODESEE PAGECODESEE PAGECODESEE PAGE
D1030I1529W 729
D1130T 929W 831
: RELAY BLOCKS
CODESEE PAGERELAY BLOCKS (RELAY BLOCK LOCATION)
219ENGINE COMPARTMENT LEFT
423LEFT KICK PANEL (J/B NO.1 LEFT)
: JUNCTION BLOCK AND WIRE HARNESS CONNECTOR
CODESEE PAGEJUNCTION BLOCK AND WIRE HARNESS (CONNECTOR LOCATION)
1B20ENGINE ROOM MAIN WIRE
1D20FRONT DOOR LH WIRE
1E20INSTRUMENT PANEL WIRE
1H
1I20COWL WIRE1J20COWL WIRE
1K
3A22INSTRUMENT PANEL WIRE3E22INSTRUMENT PANEL WIRE
SYSTEM OUTLINE
SERVICE HINTS
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15
ABBREVIATIONS
DISCONNECTION AND CONNECTION OF BOLT
TYPE CONNECTORS
For engine and ECT ECU in this vehicle, connectors are used
which require a bolt built into the connector to be screwed down to
securely connect the connector.
1. Disconnect the connectorAfter completely loosening the bolt, the two parts of the
connector can be separated.
NOTICE:
Do not pull the wire harness when disconnecting the
connector.
2. Connect the connector
NOTICE:
Before connecting the connector, always check that the
terminals are not bent or damaged.
(a) Match the guide section of the male connectorcorrectly with the female connector, then press them
together.
(b) Tighten the bolt. Make sure the connectors are completely connected,
by tightening the bolt until there is a clearance of less
than 1 mm (0.04 in.) between the bottom of male
connector and the end of female connector.
ABBREVIATIONS
The following abbreviations are used in this manual.
A/C = Air Conditioning O/D = Overdrive
ABS = Anti±Lock Brake System R/B = Relay Block
A/T = Automatic Transmission RH = Right±Hand
CB = Circuit Breaker SRS = Supplement Restraint System
COMB. = Combination SW = Switch
ECT = Electronic Controlled Transmission TDCL = Total Diagnostic Communication Link
ECU = Electronic Control Unit TEMP. = Temperature
EGR = Exhaust Gas Recirculation TRAC = Traction Control
FL = Fusible Link VSV = Vacuum Switching Valve
ISC = Idle Speed Control W/ = With
J/B = Junction Block W/O = Without
LH = Left-Hand
* The titles given inside the components are the names of the terminals (ter\
minal codes) and are not treatedas being abbreviations.
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144
ABS (ANTI±LOCK BRAKE SYSTEM)
M
A
11
MR A
4
R± A
5
SR
A
6 SFL
A
12 SRR
A
8 AST
A
9 MT
B
1 SFR
B
16 PKB
B
2 GND
B
13 GND
B
1B 4 B
3B 2B5
A 4
A 3
A 1 2 1
IG1
19
IO1
5IO1 7
EB EA 16 22 23 11
EB1
6IK1 10
IJ
EA 1
34
3 2
16
1
4
2
IK2
25 IK2 2
IE1
1
IE2
12
2 1
E10
I23I25
E9
2
6 6
666
66
66
6
B
10
WA
B
6
TS
5
6
E12 L
P±B
V±Y
L±W
L±W L
W
V±YL
W± B L±W V±YY±L
R
R
R
B±R
B±R
B±R
P±B
V
L
L
L V
L V±Y
V
R±Y
Y
B±Y P
L±W Y±G
R±W R±W
W±B
W±B
R±W
R±W
B
B
W±B
W±B W±B
W±B W±B
L±WL
W± B
SFR SFL SRR AST MT
BS
BM
GND WA
TS TC
WB
BATTERY ABS ECU
(
W/O TRACTION CONTROL )
R
120A ALT
60A ABS NO. 1
ABS MOTOR
RELAY
ABS ACTUATOR
RELAY
CHECK
CONNECTOR
FUSE BLOCK
R±W
DIODE
(FOR PARKING BRAKE )
BRAKE FLUID
LEVEL SW
PARKING
BRAKE
SW
ABS ACTUATOR
(
CANA DA )
( USA )
B1
D2
A4 , A33
P3
A2 2
,A23
B
BA A
C3
F9 SHORT PIN
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146
ABS (ANTI±LOCK BRAKE SYSTEM)
THIS SYSTEM CONTROLS THE RESPECTIVE BRAKE FLUID PRESSURES ACTING ON THE DISC\
BRAKE CYLINDERS OF THE RIGHT
FRONT WHEEL, LEFT FRONT WHEEL AND REAR WHEELS WHEN THE BRAKES ARE APPLIED IN \
A PANIC STOP SO THAT THE
WHEELS DO NOT LOCK. THIS RESULTS IN IMPROVED DIRECTIONAL STABILITY AND STEERABILITY DURING PANIC BRAKING.
1. INPUT SIGNALS
(1) SPEED SENSOR SIGNALTHE SPEED OF THE WHEELS IS DETECTED AND INPUT TO TERMINALS FL+, FR+, RL+ AND RR+ OF THE ABS ECU.
(2) STOP LIGHT SW SIGNAL A SIGNAL IS INPUT TO TERMINAL STP OF THE ABS ECU WHEN THE BRAKE PEDAL IS OPERATED.
(3) PARKING BRAKE SW SIGNAL A SIGNAL IS INPUT TO TERMINAL PKB OF THE ABS ECU WHEN THE PARKING BRAKE IS OPERATED.
2. SYSTEM OPERATION
DURING SUDDEN BRAKING, THE ABS ECU WHICH HAS SIGNALS INPUT FROM EACH SENSOR CONTROLS THE CURRENT FLOWING
TO THE SOLENOID INSIDE THE ACTUATOR AND LETS THE HYDRAULIC PRESSURE ACTING ON EACH WHEEL CYLINDER ESCAPE \
TO
THE RESERVOIR.
THE PUMP INSIDE THE ACTUATOR IS ALSO OPERATING AT THIS TIME AND IT RETURNS THE BRAKE FLUID FROM THE RESERVOIR
TO THE MASTER CYLINDER, THUS PREVENTING LOCKING OF THE VEHICLE WHEELS.
IF THE ECU JUDGES THAT THE HYDRAULIC PRESSURE ACTING ON THE WHEEL CYLINDER IS INSUFFICIENT, THE CURRENT
ACTING ON SOLENOID IS CONTROLLED AND THE HYDRAULIC PRESSURE IS INCREASED.
HOLDING OF THE HYDRAULIC PRESSURE IS ALSO CONTROLLED BY THE COMPUTER, BY THE SAME METHOD AS ABOVE. BY
REPEATED PRESSURE REDUCTION, HOLDING AND INCREASE ARE REPEATED TO MAINTAIN VEHICLE STABILITY AND TO IMPROVE
STEERABILITY DURING SUDDEN BRAKING.
A 4(B), A 33(A) ABS ACTUATOR
(A) 3, (A) 4±GROUND : ALWAYS APPROX. 12 VOLTS
(A) 1±GROUND : ALWAYS CONTINUITY
(B) 4, (B) 5, (B) 6±GROUND : APPROX. 1.15
(IGNITION SW OFF)
(B) 2±GROUND :APPROX. 5
(IGNITION SW OFF)
A 7, A 8, A30, A31 ABS SPEED SENSOR FRONT LH, RH, REAR LH, RH
1±2 : APPROX. 1.0KW (20 °C, 68°F)
A22(A), A23(B) ABS ECU
(B) 11±GROUND : APPROX. 12 VOLTS WITH IGNITION SW ON
(B) 2, (B) 13±GROUND : ALWAYS CONTINUITY
(B) 22±GROUND : ALWAYS APPROX. 12 VOLTS
(B) 1, (A) 6, (A) 12±GROUND : APPROX. 12 VOLTS WITH IGNITION SW ON
(B) 16±GROUND : CONTINUITY WITH PARKING BRAKE LEVER PULLED UP
(B) 7±GROUND : APPROX. 12 VOLTS WITH STOP LIGHT SW ON
P 3 PARKING BRAKE SW
1±GROUND : CLOSED WITH PARKING BRAKE LEVER PULLED UP
S12 STOP LIGHT SW
1±2 : CLOSED WITH BRAKE PEDAL DEPRESSED
SYSTEM OUTLINE
SERVICE HINTS
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134
ABS AND TRACTION CONTROL
34
3 2
16
1
4
26
666
66
66
6 56
ABS MOTOR
RELAY
ABS ACTUATOR
RELAY4 1
3
26
6
66TRACTION MOTOR
RE LA Y
M
A
13 SFL C
12 SRL
A
8 AST
A
7 MT
B
1 SFR
B
4B 51B 2B3
A 2
A 1
C 1
L±W
L
Y
B±Y
P±B
L±W Y±G
SFR SFL SRL AST MT
BS
BM
GND
ABS ACTUATOR A4,A5 ,A6 B
B C
A
EA
EB B
16
MR A
9
TMR
A
22
SR
A
25
R± E10
E12
6
11 2
L±Y
W±B V±Y
W±B B±R
R
Y R
W±B V±Y
W±B W±B
W±B
Y
V±Y
R±B G Y
R R
W±B L±W
V±Y
V±Y
G V±Y
L
L±W
L
W±B W±B W±B W
R Y
30A ABS NO. 2
60A ABS NO. 1 120A ALT
BATTERY
FUSE BLOCK
ABS AND TRACTION ECUA
26 SRR
6
P
SRR B
A24
,A25 ,
A26
F9
B
A
B
A
5 FL+
A
18 FL ±
21 (
SHIELDED )
W
B
B
W
A7
FRONT LH
E2
V±Y
W±B
V±Y
R±B
V±Y
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135
B
4 RL+
B
15 RL±
B
5 RSS
B
14 RR+
B
3 ALT
BW1
3BW1 8
BW1
2
BW1
5
BW1
6
Bc2
6
Bc2
2 I26
12 12
W O W±B
L±G
L±Y
W
O
L±G L±Y
W
O
L±G L±Y
(
SHIELDED ) (
SHIELDED )
(
SHIELDED )
REAR LH REAR RH A3 1
A3 0
ABS SPEED SENSOR
M
6
1
4
36
6
66
TRACTION BRAKE
MAIN RELAY
2 16 22
3
1 23 11
E7
I25 I32
I23
EB1
6
IO1
7 IK2
2
A
23
MTT A
1
TSR A
20
E2 A
19
VC A
10
PR A
15
SRC A
2
SMC A
12
SAC C
1
TS B
9
WA C
3
TC
A
1A 2A3
A
4A 5A6
B
2
B
1 B
4
L±Y
B±R
L
L
L
L VB±R
P±B
P±B B±R
R±W
R±W
R±W
W
R
B
V±Y V
V±W B±R
R
R±W
V±Y
TS WA
R
B±R
L±Y
W±B V±Y
W±B W±B P±B
L
TC
WB
T5 T3
,
T4C3
TRACTION PUMP
AND MOTOR TRACTI ON BRA KE
ACTUATOR
CHECK
CONNECTOR
BA
(
SHIELDED )
C
ABS AND TRACTION ECU A24 ,
A25 ,A26
AB P±B
P±B
ACC CUT MIC CUT
RESERVOIR
CUT
(
SHIELDED )
A
17 FR+
A
4 FR±
A
16 FS S
I26
21(
SHIELDED )
O±L
W±L W±B
W±L O±L
A8
FRONT RH B
8
IO1
10
3B
1
3B
2
IJ 1
5 IG3
1
A1 0
ALTERNATOR Y±G
Y±G
Y±G
Y±G
Y±G
RR±
I26
B17
BR
BR
I26
B34
BW1
7
Bc2
5 B17
B36
BR±B BR±B BR±B
BR±B
(
SHIELDED )
2
SHORT
PIN
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136
ABS AND TRACTION CONTROL
I16E9
I14
I25 I25
I4
E13 I7
1E
12 1I 10 2 1I 8
14 8 17 4
IO1
8
IK2
9 3E
3
A1
B
15 B 5B1
B
22 GND1
B
2 GND2
B
13 GND3
B
6 LBL
B
17 PKB C
7 ABSO
C
12 BRP
C
8 BRC
C
7 THFA
C
11 BRFA
C
15 FRO
C
6 FL O
C
10 P
C
5 N
B
20
D/G B
10
STP B
21
BATT A
24
IG
3A
4
3D13
IK25 IO1
1IE2 7
1 2
I7 1H1
1E20
FROM POWER SOURCE SYSTEM
(
SEE PAGE 56 )
2 1 2 1
2 1 1
EA
IJ IG1
19 IG1 20IK2
18
IE2
12 IE1
1 IO1
9
P±B
Y
W
G±W
G±W
R
B±R
B±R R
G±W
Y
LG±R W
L V±W
L±Y W
G±W B±R
R±B
R±B
L
GR LG
LG±B P±L
P±G
V±R
B±Y
W±B
W±B
W±B
R±W
R±W
R±W
R±W
B
R±W
R±W
R±WR±B
B
W±B W±B W±B
V±W
L±Y
L
P±B
R±W R±W
B WW
R±W
10A
GAUGE
15A
STOP10A
DOME15A
ECU±IG
WTRC
ABS TC
G±W
COMBINATION METER STOP LIGHT
SW
TDCL
ABS AND TRACTION ECU
B
B
PARKING
BRAKE SW
BRAKE FLUID
LEVEL SW
DIODE
(FOR BRAKE FLUID LEVEL )
DIODE
( FOR P ARK I NG
BRAKE ) (
CANADA )
(
USA )
A24
,A2 5
,A26
C13
,
C14
T6 S12
P3
B1 D1
D2
B
A
B B±R
R
G± W
LG±R W
L±Y
B±Y
V±R
P±G P±L
LG±B LG
GR L
R±B
R±W
IK 1
10
3H
12
P±B
TRAC OFF TRAC ANTI
LOCK
A
B 2
1
P±B
P±B
P±B
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137
B±RR
G±W
LG±R W
L±Y
B±Y
V±R
P±G P±L
LG±B LG
GR L
R±B
R±W TRACTION E CUE9 , E10
AB
I33
I36 I36 2
IK2
15 EB1 5
1B
5
3A6
B
11
IND B
14
WT B
8
BAT B
2
STP
A
16
TR5 A
2
IG A
15
BM A
21
TR2 A
6
NEO A
8
VTH A
19
VSH
A
4 TRCO
A
5 THFA A
4 W
A
37 TR
A
38 NEO
A
40 VT01
A
39 VT02
B
6 TC
B
1 BRC
B
4 BRFA
B
10 FRO
B
3 FL O
B
7 P
B
16 N
B
15 ABSO
B
5 RLO
A
1 PKB
C
13 RRO
C
4 RLO
C
14 TRCO 1E
11
3B3
IJ2 12
IK2 4 IJ2
7
IK112
IK1 13 A
23 BRP
L±R
L±Y
Y±R P±L
V±Y Y±L
L±Y
W
LG±R
B±R R
G±W L±R
Y±R P±L
V±Y Y±L
P
R±W B±Y
V±R
P±G P±L
LG±B
LG
GR L
R±B
R±W P
R±W
L±YR
L±R
GRLG± R L
Y±B
LG±R
G±W
B±R
RR FROM POWER SOURCE SYSTEM
(
SEE PAGE 56 )
7. 5A
TRAC
GR L
FROM A/T INDICATOR SW ENGINE AND ECT ECU
T1 3 ,T14
BA 13 14
I33 A
6
STP
G±W
G±W
B
12 RRO
P±B
P±B
IK2
13
3H
7
3F
2
R±W R±W
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138
ABS AND TRACTION CONTROL*1 : USA SPEC.
B
41 VC
B
43 VTA
B
64 IDL
B
46 THG
B
63 IDL2
B
44 THW
B
69 E1
A
26 BCM
A
25 B
A
24 B
A
11 A
A
12 A
A
13 ACM
A
14 GN D
A
20 E1
B
13 CSWA
10
IDL1 A
22
IDL2
1
2
3
4
VC VTA IDL E2 1
2
3
4
VC VTA IDL E2
E18
I32
E18
I37 I32
6 2
IF IJ ED
3H
14
1E
18 3A
1
1J
1 213645 BR
L±R RR±B
BR
BR
BRG
R±B R
Y
L±R
R±B R
BR
BR
R±B
Y±L BR
RY
L±R
Y
R L
W G
BR
W±B
BR
W±B
BR W±B
W±B
W±B
B+ B± B A A± A+
L±R
TO AI R FL OW
METER
(
VC )
FROM AIR FLOW
METER(
E2 )
THROTTLE POSITION
SENSOR SUBTHROTTLEPOSITION
SENSOR
IK2
16
Y±R
Y±R
S UB THROTTLE A CTUATOR
TRACTION
CUT SW TRACTION ECU
T12
S8
T1 3 , T 1 4
A B S9
T2 ENGINE AND ECT ECU E9
,E10
B A
IJ1
13
W±B (
SHIELDED )
E20 B
65 E2
BR
I32
B
42 VTA2
Y±LBR
1 2
1
2
BRE3
EGR GAS TEMP
SENSOR
EFI WATER
TEMP. SENSOR
A
3 S1
BR (
*1 )
(
*1 )
E2
±±
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