ECU LEXUS SC400 1991 Service Repair Manual

214
RADIO AND PLAYER (w/o CD PLAYER)
II
FROM POWER SOURCE SYSTEM
(
SEE PAGE 56 )
BV2
8Bc1 10 Bc21Bc1 24 BV1 4BV15BV16BV13
Bc1
23 Bc1 8Bc19 BV1 19 BV17BV118 BV2
2BV2 1
B19
B19
B16 B1 9
I31
IC
6
BM C
9A 5A1A2
C
8A 4A10 C 1C5
C
7
Bc2
4Bc2 3
P±L P±L P±L P±L
GR
L±Y GR
L±Y
P±L
P±G
L±W Y±R BR
LGL
B±R
GR
L±Y
B±R
GR
GR
L±Y
P±L L±Y
Y±R
L±W P±G
P±G
L±W Y±R BR
LGL
LG
L
LG W±B
BR
W±B
P±LWB
R±B P±L
W B P±B
R±W
B±W GR
L±Y GR
WOOFER SPEAKER AMPLIFIER W10
W9
WOOFER
SPEAKER
RADIO A ND P LA YER ABCD
R2 ,R3
,R5
,R
6
AUTO ANTENNA MOTOR
AND RELAY A32
AB
T16 T17
TELEPHONE
TRANSCEIVER AND
SPEAKER RELAY
651210 9
7125 43
3
8
6 7
15A
ECU±IG
AMP RU± RU+ MUTE WP+ WP±ACC +B
P±L
21
4
IG ACC
MUTE
ANTB ANTA FR±
AMP
IQ2
12
BR
BR
(W/ TEL )
(
W/O TEL )L
(
W/ TEL )
E
(
W/O TEL )
AMP RU± RU+
ANT ANT ANTA ANTB E FR+
FR±
B
FR+
(
SHIELDED )
(
SHIELDED )
A
5A 12
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188
SHIFT LOCK
1E
21E 17 1I 10
7 8 SHIFT LOCK
CONTROL SW
SHIFT LOCK
SOLENOID
TIMER
3
2 4
5
1
P1
±P
P2
SLS±
SLS+
1 2
IF 15A
CIG
15A
ECU±IG 15A
STOP
KEY INTERLOCK
SOLENOID
[IGNITION SW] STOP LIGHT
SW
ACC IG STP
KLS+ EL±RL
G±W G
G±R
V
W±B
W±B W±B
L±R
B±R
G±W G±W W B±R
L±R
SHIFT LOCK ECU
FROM POWER SOURCE SYSTEM
(
SEE PAGE 56 )
I15 S12
S10
1H
1
3A
5
3G
6
1E
20
IG1
12
1H
13
1J
1 1E
18
V
3A
1 3H
15
W±B
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189
WHEN THE IGNITION SW IS TURNED TO ACC POSITION THE CURRENT FROM THE CIG FUSE FLOWS TO TERMINAL 1 OF THE SHIFT
LOCK ECU, IN THE ON POSITION, THE CURRENT FROM THE ECU±IG FUSE FLOWS TO TERMINAL 5 OF THE ECU.
1. SHIFT LOCK MECHANISM
WITH THE IGNITION SW ON, WHEN A SIGNAL THAT THE BRAKE PEDAL IS DEPRESSED (STOP LIGHT SW ON) AND A SIGNAL THAT
THE SHIFT LEVER IS PUT IN ªPº RANGE (CONTINUITY BETWEEN P1 AND P OF THE SHIFT LOCK CONTROL SW) IS INPUT TO THE
ECU, THE ECU OPERATES AND CURRENT FLOWS FROM TERMINAL 5 OF THE ECU " TERMINAL SL+ OF THE SHIFT LOCK
SOLENOID " SOLENOID " TERMINAL SL± " TERMINAL 3 OF THE ECU " GROUND. THIS CAUSES THE SHIFT LOCK SOLENOID TO
TURN ON (PLATE STOPPER DISENGAGES) AND THE SHIFT LEVER CAN SHIFT INTO RANGE OTHER THAN THE ªPº RANGE.
2. KEY INTER LOCK MECHANISM
WITH THE IGNITION SW ON OR ACC POSITION, WHEN THE SHIFT LEVER IS PUT IN ªPº RANGE (NO CONTINUIT\
Y BETWEEN P2 AND P
OF SHIFT LOCK CONTROL SW), THE CURRENT FLOWING FROM TERMINAL 2 OF THE ECU " KEY INTER LOCK SOLENOID IS CUT
OFF. THIS CAUSES THE KEY INTER LOCK SOLENOID TO TURN OFF (LOCK LEVER DISENGAGES FROM LOCK POSITION) AND THE
IGNITION KEY CAN BE TURNED FROM ACC TO LOCK POSITION. IF THE IGNITION IS LEFT IN ACC OR ON POSITION WITH THE SHIFT
LEVER IN OTHER THAN ªPº RANGE, THAN AFTER APPROX. ONE HOUR THE ECU\
OPERATES TO RELEASE THE LOCK.
S10 SHIFT LOCK ECU
1±GROUND : APPROX. 12 VOLTS WITH IGNITION SW AT ACC OR ON POSITION
5±GROUND : APPROX. 12 VOLTS WITH IGNITION SW AT ON POSITION
3±GROUND : ALWAYS CONTINUITY
4±GROUND : APPROX. 12 VOLTS WITH BRAKE PEDAL DEPRESSED
S12 STOP LIGHT SW
2±1 : CLOSED WITH BRAKE PEDAL DEPRESSED
: PARTS LOCATION
CODESEE PAGECODESEE PAGECODESEE PAGE
I1529S1029S1229
: JUNCTION BLOCK AND WIRE HARNESS CONNECTOR
CODESEE PAGEJUNCTION BLOCK AND WIRE HARNESS (CONNECTOR LOCATION)
1E20INSTRUMENT PANEL WIRE
1H
1I20COWL WIRE
1J
20COWL WIRE
3A
3G22INSTRUMENT PANEL WIRE
3H
: CONNECTOR JOINING WIRE HARNESS AND WIRE HARNESS
CODESEE PAGEJOINING WIRE HARNESS AND WIRE HARNESS (CONNECTOR LOCATION)
IG136INSTRUMENT PANEL WIRE AND COWL WIRE (R/B NO. 5)
: GROUND POINTS
CODESEE PAGEGROUND POINTS LOCATION
IF36LEFT KICK PANEL
X 78 12345
12
I15 S 10 S 12
BLACK
SYSTEM OUTLINE
SERVICE HINTS
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180
SRS AIRBAG
1G
10 1G 6
1G
11E 13
10 11
IK1
10 IK1 23
IK 1
1
4
+SL
5±SL
3+SR
2±SR
11D+
10D±
13E1
8E2
3E1
3E1
7
IG2 14
ACC 6
+B
12AB 4
TC 11
TC 5
AB
121212 7. 5A
IGN
15A
CIG 15A
ECU±B
FROM ENGINE AND
ECT ECU(
E1 )
CHECK
CONNECTOR
TDCL
FRONT AIRBAG
SENSOR LH FRONT A I RBA G
SENSOR RH
AIRBAG SQUIBSPIRAL
CA BLE
CENTER AIRBAG SENSOR ASSEMBLY
BR
W±B W±BL
Y B
GR
WR
L
Y
B
GR
WR
BR W±B
BR BR BR B±Y P±BP±B
B±Y
P±B
B±Y B±Y W±RW±R
L±R
B±O
FROM POWER SOURCE SYSTEM
(
SEE PAGE 56 )
AIRBA G WA RNING
LIGHT
[COMB. METER]
C10
F1 F2 A2 9 C3
T6 C12
E2 0
1G
9 912
IF ED 1G
7
EC
LA TC
1E
41E 3
3B
2
3H
12
3E
3
3E
10
1J
1 3A
3
1G
4
1G
3 3A
73D 11
B±Y
P±B
B±Y
P±B
B±Y
W±B
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62
STARTING AND IGNITION
AM1
AM2
11 4
1
6
ST1
IG2
A
1
B 1 1J
6
1J
7
2
22
1B
4 1K
4
6 9 4 14 13 7 M
IE1
16
EB2
1 IE1
15
E19
L±O
L±O B
B
B WW±R
W± RW
W±L
W±RW±L W
W
B±O
B±W
B
B
B
B
W± R
BATTERY
STARTER
31
52
IGNITION SW
40A
IGSW
STARTER
RELAY 7. 5A
ST
FUSE BLOCK
TO THEFT DETERRENT AND
DOOR LOCK ECU 30A AM2
120A ALT
100A AM1
30A INJ
60A MAIN
I15
S6 , S7
F9
BA
3
4
2 1
2
3 IJ1
6
EB1
3
IJ28
IJ1
7
B±O
B
B
B
BB±W B±W
B±W
(A/T )
( M/T )
NEUTRAL
START SW CLUTCH
START SW
N1 C23
( A/T )
( M/T )
2
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63
E18E14
E20
2 1
ED
W± L
B
B±O
B
W± B B±OB±O
B±O
BB
B± O
TO COMBINATION
METER
(
TACHO )12
DISTRIBTOR
IGNITION COIL
I4
D13
IG± TAC +B
IGF IGT C±
IGNITER
CHECK
CONNECTOR
C3 I2
435
19
12
STA IGF IGT
77 58 57
ENGINE AND ECT ECU (
A/T )
E10
NOISE FILTER
(
FOR IGNITION SYSTEM )
N31234
27 26 25 7 NE G1 G2 G± NE G1 G2 G±
L
R Y
B
W±Y
R±Y
ENGINE ECU
(
M/T )
E12
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11 2
THEFT DETERRENT AND DOOR LOCK CONTROL
2
1I
14
1K
13
1K
11 2
3A
1
1J
1
1B
22
1H
13 3F
7
1E
18 1I
16 4
4
1D
8 1H
10 1B
5
1D 10 I8
I11
I11
B4
9
10
1 2IE1
6
IG1
17 IF2 15 IF214
IF2
16 IF2 18 IF2 5IF24
IF2
7
B
13
TAIL B
5
HE AD A
2
IG B
7
ACC A
20
+B1
A
16 E
A
6 KSW
A
19 TSW
A
14 L1
A
10 UL3
A
13 DSWD
A
11 LSWD
A
17 L2
A
18 UL2
1
13
6 4
7 24
2
31
8
21
IF 2 1
M
64 5 31 2
FROM POWER SOURCE SYSTEM
(
SEE PAGE 56 )
60A MAIN
120A ALT
100A AM1
LOCK
UNLOCK
LOCK
UNLOCK
15A
ECU±IG 15A
CIG10A
DOME
HEA DLIGHT
RELAY
G±Y
G±Y
G±L
R±B
L±W
L±R
W±B
W±B
W±B
W±L W
W
B±RL±R R
R
R±Y
G±W
W±B
Y
L
G±Y G G±Y
R±B
W±L
R±BG± L
R±B
G±L
L±W
L±W
R±W
L±W
L±W
R±BG±L
W±B L±R
W±B W±B W±B
G
G±Y L
W±B
W±B W±B
R±YTAI L LI GHT
RELAY
W±LW
TO FUSE º 15A TAILº
THEFT DETERRENT AND DOOR LOCK ECU
UNLOCK WA RNING SW
[IGNITION SW]
LUGGAGE COMPARTMENT
DOOR OPENER SW
DOOR KEY LOCK AND
UNLOCK SW LH
DOOR LOCK MOTOR,
DOOR UNLOCK DETE CTION AND
DOOR OPEN DETECTION SW LH
POWERWINDOWMASTERAND
DOOR LOCK CONTROL SW LH
FUSE BLOCK
L±R
BATTERY
F9
I15
L1
D7
D10
P5
T8 , T9 B A
DIODE
32 51 2
W±B
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11 3
M
64 5 31 2
1K
4
2
2
2 2
I11
B7 B7 I11
EB1
3 IE1
15
IP1
20
IP1
8IP1 19
IP 1
15 IP1 6IP1 18 IP1 5IP114 IE 1
14 BT1 9
IP1
7
A
15 UL1
A
12 DSWP
A
7 LSW P
A
3 ACT±
A
4 ACT+
B
12 DS WH
A
5 TOA
1
SRLY25 13
2
31
2
31
IJ EA
2 1
PRND 2 L
146578 9
GR
R±B
L
G±W G
W
A/T INDICATOR SW
[NEUTRAL START SW AND BACK±UP LIGHT SW]
N1
2
3
FROM POWER SOYURCE SYSTEM
(
SEE PAGE 56 )
7. 5A
ST
P
N STARTER
RE LA Y
THEFT DETERRENT AND DOOR LOCK ECU
LOCK
UNLOCK
LOCK
UNLOCK
DOOR KEY LOCK AND
UNLOCK SW RH
DOOR LOCK MOTOR,
DOOR UNLOCK DETE CTION AND
DOOR OPEN DETECTION SW RH DOOR LOCK
CONTROL SW RHENGINE HOOD
COURTESY SW
LUGGAGE COMPARTMENT
DOOR OPENER MOTOR
G± Y G±L
R±B
L±W
L±R W±B
L±R L±R B
Y
W
B
L±O B
B
L±O
B
G±L L±R
G±L B
W±B W±B
L±R
W±B W±B W±B
W±B W±B
L±R R±BG±L
L±W
P±B
R±W G±W
G±Y G±Y
G±W
R±W P±B
L±W
R±BG±L L±W
P±B
R±W
G±W
L4 E5
D9
D11 D8
T8
,T
9
B A
M
1
IJ1
6
B±W
( A/T )
IJ28
B±W B
( M/T )(
M/T)
B±W
( A/T )
B±W
( M/T )
CLUTCH STA RT
SW (
M/T )
C23
( A/T )
B3 3
W±BW±B
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11 4
THEFT DETERRENT AND DOOR LOCK CONTROL
2
5
1K
71E 5
44 1I
71J 1
3 11 IE1
9
2
1
BM IF BL
BT1
8BT1 7IG1 2IJ1
4
IJ1
9
B
11
HORN B
4
SH B
8
PRLY A
8
+B 2
B
1 LUG
B
10 DS WL
A
9 IND
4
I72
12
1
4
3
3
15
10 1 2
BY1
8
IH FROM POWER SOURCE SYSTEM
(
SEE PAGE 56 )
25A
HAZ±HORN 30A
POWER30A
DOOR
POWER
MAIN
RELAY
W
WW W
G±R
WW
B±O
B±O
Y±RW±B
L±W
L±W
L±R
L±R
W±B W±B G±B
R±W L±G
L±G
R±W G±B
R
BR W±B
TRIP S W AND
THEFT DETERRENT
INDICATOR LIGHT
COMB INATION
METER
FUEL L I D
OPENER SOLENOID
FUEL LI D
OPENER SW
THEFT
DETERRENT
HORN
HORN
RELAY
LUGGAGE COMPARTMENT
LIGHT SW LUGGAGE COMPARTMENT
KEYUNLOCKSW
THEFT DETERRENT AND DOOR LOCK ECU T8
,T9 T1
F1 0
F1 4
T1 5
C14
L6 L5
B
A
B
6
52
31
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11 5
CURRENT ALWAYS FLOWS TO TERMINAL (A)8 OF THE DOOR LOCK ECU THROUGH THE DOOR FUSE, AND TO TERMINAL (A)20
THROUGH THE DOME FUSE.
WHEN THE IGNITION SW IS TURNED ON, THE CURRENT FLOWING THROUGH THE ECU±IG FUSE " TERMINAL (A)2 OF THE ECU "
TERMINAL (B)8 FLOWS THROUGH THE COIL SIDE OF THE POWER MAIN RELAY TO GROUND, CAUSING THE RELAY TO OPERATE.
THE CURRENT FLOWING THROUGH THE POWER FUSE FLOWS TO THE DOOR LOCK CONTROL SW LH, CAUSING THE INDICATOR
LIGHT TO LIGHT UP.
1. MANUAL LOCK OPERATION
WHEN THE DOOR CONTROL SW OR KEY SW ARE PUSHED TO LOCK POSITION, A LOCK SIGNAL IS INPUT TO TERMINAL (A)17, (A)14
(FOR KEY SW) OF THE DOOR LOCK ECU AND CAUSES THE ECU TO FUNCTION. CURRENT FLOWS FROM TERMINAL (A)8 OF THE
ECU " TERMINAL (A)4 " TERMINAL 5 OF THE DOOR LOCK MOTORS " TERMINAL 2 " TERMINAL (A)3 OF THE ECU " TERMINAL
(A)16 " TO GROUND AND THE DOOR LOCK MOTOR CAUSES THE DOOR TO LOCK.
2. MANUAL UNLOCK OPERATION
WHEN THE DOOR LOCK CONTROL SW OR KEY ARE PUSHED TO UNLOCK POSITION, AN UNLOCK SIGNAL IS INPUT TO TERMINAL
(A)18, (A)10 (FOR KEY SW LH) OR (A)15 (FOR KEY SW RH) OF THE DOOR LOCK ECU AND CAUSES THE ECU TO FUNCTION.
CURRENT FLOWS FROM TERMINAL (A)8 OF THE ECU " TERMINAL (A)3 " TERMINAL 2 OF THE DOOR LOCK MOTORS " TERMINAL
5 " TERMINAL (A)4 OF THE ECU "TERMINAL (A)16 " TO GROUND AND THE DOOR LOCK MOTOR CAUSES THE DOOR TO
UNLOCK.
WHEN UNLOCK OPERATION OCCURS USING THE LH DOOR KEY SW, PERFORMING THE UNLOCK OPERATION ONCE UNLOCKS
ONLY THE DRIVER'S DOOR. TO UNLOCK ALL THE OTHER DOORS TOGETHER, UNLOCK OPERATION MUST BE PERFORMED AGAIN
WITHIN 3 SECONDS OF THE FIRST OPERATION.
3. IGNITION KEY REMINDER OPERATION
* OPERATION OF DOOR LOCK BUTTON (OPERATION OF DOOR LOCK MOTORS)
WHEN THE IGNITION KEY IS IN THE CYLINDER (UNLOCK WARNING SW ON) AND THE DOOR IS OPENED AND LOCKED USING
DOOR LOCK BUTTON (DOOR LOCK MOTOR), THE DOOR IS LOCKED ONCE BUT EACH DOOR IS UNLOCKED SOON BY THE
OPERATION OF THE ECU. AS A RESULT OF ECU ACTIVATION, THE CURRENT FLOWS FROM TERMINAL (A)8 OF THE ECU "
TERMINAL (A)3 " TERMINAL 2 OF THE DOOR LOCK MOTORS " TERMINAL 5 " TERMINAL (A)4 OF THE ECU " TERMINAL (A)16
" TO GROUND AND CAUSES ALL THE DOORS TO UNLOCK.
THE SAME APPLIES TO OPERATION OF THE DOOR LOCK CONTROL SW AND DOOR LOCK KEY SW.
* KEY LESS LOCK OPERATION
WHEN THE IGNITION KEY IS STILL INSERTED IN THE CYLINDER (UNLOCK WARNING SW ON), THE DOOR IS OPEN AND UNLOCK
OPERATION IS PREVENTED BY KEEPING THE DOOR LOCK BUTTON PRESSED TO THE LOCK SIDE, THE DOOR IS KEPT IN THE
LOCK CONDITION. IF THE DOOR IS THEN CLOSED, A SIGNAL IS INPUT TO THE ECU FROM THE DOOR COURTESY SW. THIS
ACTIVATES THE ECU AND EACH DOOR IS UNLOCKED.
SYSTEM OUTLINE
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