Toyota land cruiser 1998 2007 diagnostics hệ thống chuẩn đoán lỗi trên land cruiser đời 1998 2007

F17763
EXI
WT
A43
A43
IX1
F15
Cowl Side J/B RH
Cowl Side J/B RH
Cowl Side J/B RH
Cowl Side J/B LH
I18
Ignition SW
Engine Room J/B
Combination Meter
ABS & BA & TRAC
& VSC ECU
SB
D4
Detection SW
(Center Diff. Lock)
2
W-B
P-B
SB
SB
SB
MET
1
2
47

3E
3Q
56 3
3Q
3B
3Q
3B
J4
J/C
B-R B-R
A
A
P-B
L-R
W-R AM2 IG2
76
41 10
2E 2A
1
9
1C
1B
2
B-G
EC
FL Block
Battery
MAIN
EC
BR

W-R
8
IX1
VSC OFF
17
C13
C12
C15
1
10
3
7
1426
AM2
DI-624
-DIAGNOSTICS ABS & VEHICLE STABILITY CONTROL (VSC) &
BRAKE ASSIST (BA) SYSTEM
817A uthor: Date:
2004 LAND CRUISER (RM1071U)
DTC Always ON Malfunction in ECU
VSC TRAC Warning Light Circuit
CIRCUIT DESCRIPTION
Always ON There is a malfunction in the ECU internal circuit.
L Power source circuit
L Skid control ECU
L VSC TRAC warning light circuit
HINT:
If the fail safe function is activated in the VSC system, ”VSC OFF” indicator light lights up.
WIRING DIAGRAM
DICA4-01

-DIAGNOSTICS ABS & VEHICLE STABILITY CONTROL (VSC) &
BRAKE ASSIST (BA) SYSTEM
DI-625
818A uthor: Date:
2004 LAND CRUISER (RM1071U)
INSPECTION PROCEDURE
1 Check that the ECU connectors are securely connected to the ECU.
NO Connect the connector to the ECU.
YES
2 Is DTC output for VSC?
Check the DTC on page DI-505 .
YES Repair circuit indicated by the output code.
NO
3 Does VSC TRAC warning light go off?
YES Check for open or short circuit in harness and
connector between ECU-IG fuse and ECU (See
page IN-36 ).
NO
4 Check battery positive voltage.
PREPARATION:
Start the engine.
CHECK:
Check the battery positive voltage.
OK:
Voltage: 10 to 16 V
NG Check and repair the charging system.
OK
DI-626
-DIAGNOSTICS ABS & VEHICLE STABILITY CONTROL (VSC) &
BRAKE ASSIST (BA) SYSTEM

819A uthor: Date:
2004 LAND CRUISER (RM1071U)
5 Check operation of the VSC TRAC warning light.
In case of using the hand-held tester:
PREPARATION:
(a) Connect the hand-held tester to the DLC3.
(b) Turn the ignition switch ON and push the hand-held tester main switch ON.
(c) Select the ACTIVE TEST mode on the hand-held tester.
CHECK:
Check that ”ON” and ”OFF” of the VSC TRAC warning light can be shown on the combination meter on the
hand-held tester.
In case of not using the hand-held tester:
PREPARATION:
(a) Turn the ignition switch OFF.
(b) Disconnect the connector from the skid control ECU.
(c) Turn the ignition switch ON.
CHECK:
Check that the VSC TRAC warning light goes off.
NG Check and replace combination meter (See
page BE-2 ).
OK
6 Check for short circuit in harness and connector between combination meter and skid
control ECU, combination meter and DLC1 (See page IN-36 ).
NG Repair or replace harness or connector.
OK
Check and replace skid control ECU.
F17718
F18533
ABS & BA & TRAC
& VSC ECU

Engine Room J/B
Combination Meter
Cowl Side J/B RH
Cowl Side J/B LH
I18
Ignition SW
Cowl Side J/B RH
WA
1
A42
4
3A
5
3Q
12
C12
41
2E
10
2A
1B
91
1C
AM2
W-R
B-R
C12
C15
EC
SB

BR
8
IX1
3Q
SB
7
MET
4
3E
B-R
B-G
FL Block
SB R-L
W-R
76
AM2 IG2
J4
J/C
AA
2
F15
Battery
1
10
MAIN
ABS
-DIAGNOSTICS ABS & VEHICLE STABILITY CONTROL (VSC) &
BRAKE ASSIST (BA) SYSTEM
DI-627
820A uthor: Date:

2004 LAND CRUISER (RM1071U)
ABS Warning Light Circuit
CIRCUIT DESCRIPTION
If the ECU detects trouble, it lights the ABS warning light while at the same time prohibiting ABS control. At
this time, the ECU records a DTC in memory.
Connect terminals Tc and E
1
of the DLC1 or Tc and CG of DLC3 to make the ABS warning light blink and
output the DTC.
WIRING DIAGRAM
DICA5-02
DI-628
-DIAGNOSTICS ABS & VEHICLE STABILITY CONTROL (VSC) &
BRAKE ASSIST (BA) SYSTEM
821A uthor: Date:
2004 LAND CRUISER (RM1071U)
INSPECTION PROCEDURE
HINT:
Troubleshoot in accordance with the table below for each trouble symptom.
ABS warning light does not light up *
1
ABS warning light remains on *
2
*
1
: Start the inspection from step 1 in case of using the hand-held tester and start from step 2 in case of not
using the hand-held tester.
*
2
: After inspection with step 4, start the inspection from step 5 in case of using the hand-held tester and

start from step 6 in case of not using hand-held tester.
1 Check operation of the ABS warning light.
PREPARATION:
(a) Connect the hand-held tester to the DLC3.
(b) Turn the ignition switch ON and push the hand-held tester main switch ON.
(c) Select the ACTIVE TEST mode on the hand-held tester.
CHECK:
Check that ”ON” and ”OFF” of the ABS warning light can be shown on the combination meter on the hand-
held tester.
OK Check and replace skid control ECU.
NG
2 Does the warning lights other than ABS warning light come on?
YES Repair ABS warning light bulb or combination
meter assembly.
NO
F00044
1
2
3
4
(+)
(-)
Continuity
12
34
1
2
3
4
Open

Continuity
-DIAGNOSTICS ABS & VEHICLE STABILITY CONTROL (VSC) &
BRAKE ASSIST (BA) SYSTEM
DI-629
822A uthor: Date:
2004 LAND CRUISER (RM1071U)
3 Check IG1 No. 1 relay.
PREPARATION:
Remove the IG1 No. 1 relay from the engine room J/B.
CHECK:
Check continuity between the IG1 No. 1 relay terminals listed
in the table below.
OK:
Terminals 3 and 4 Continuity
Terminals 1 and 2 Open
CHECK:
(a) Apply battery positive voltage between terminals 3 and 4.
(b) Check continuity between terminals.
OK:
Terminals 1 and 2 Continuity
NG Replace IG1 No. 1 relay.
OK
Check for open circuit in harness and connector between IG1 No. 1 relay and combination meter
(See page IN-36 ).
DI-630
-DIAGNOSTICS ABS & VEHICLE STABILITY CONTROL (VSC) &
BRAKE ASSIST (BA) SYSTEM
823A uthor: Date:
2004 LAND CRUISER (RM1071U)
4 Check that the ECU connectors are securely connected to the ECU.

NO Connect the connector to the ECU.
YES
5 Check operation of the ABS warning light (See step 1).
OK Check and replace skid control ECU.
NG
6 Is DTC output?
Check the DTC on page DI-505 .
YES Repair circuit indicated by the output code.
NO
7 Check for short circuit in harness and connector between ABS warning light and skid
control ECU (See page IN-36 ).
NG Repair or replace harness or connector.
OK
Check and repair skid control ECU.
F17750
F18532
ABS & BA & TRAC
& VSC ECU
Cowl Side J/B RH
Combination Meter
Cowl Side J/B RH
Engine Room J/B
Cowl Side J/B LH
Cowl Side J/B LH
I18
Ignition SW
FL Block
Cowl Side J/B LH
WA
IG2

A42
A44
R-L
3A
4
3Q
5
SB
C12
12
ABS
10
C12
C15
1
SB
IX1
8
BR
EC
IF
IF
EE
W-B
3
2A
2B
13
A41
6

A41
31
A42
8
A42
17
A42
6
GND4
GND3
GND1
GND2
3Q
7
3B
22
MET
IGN
3E
4
B-R
A
A
J4
J/C
B-R
6
4
7
2

AM2 IG2
AM1
IG1
B-W
B-R
L-B
2E
37
2B
18
2E
39
ECU-IG1
2
3
5
1
IG1 No.2 Relay
2C
1
B-G
F16
1
B-G
F15
2
J/B No.2
ALT
MAIN
Battery

W-R
2A
10
2E
41
1C
1
AM2
1B
9
B-R
SB
AM1
1
22
IG1
W-B
W-B
W-B
W-B
W-B
W-R
W-B
W-B
-DIAGNOSTICS ABS & VEHICLE STABILITY CONTROL (VSC) &
BRAKE ASSIST (BA) SYSTEM
DI-621
814A uthor: Date:
2004 LAND CRUISER (RM1071U)
DTC Always ON Malfunction in ECU

CIRCUIT DESCRIPTION
DTC No. DTC Detecting Condition Trouble Area
Always ON
Either of the following 1. or 2. is detected:
1. The ECU connectors are disconnected from the ECU.
2. There is a malfunction in the ECU internal circuit.
L Battery
L IC regulator
L Power source circuit
L Skid control ECU
HINT:
The hand-held tester may not be used when the ECU is abnormal.
WIRING DIAGRAM
DICA3-01
DI-622
-DIAGNOSTICS ABS & VEHICLE STABILITY CONTROL (VSC) &
BRAKE ASSIST (BA) SYSTEM
815A uthor: Date:
2004 LAND CRUISER (RM1071U)
INSPECTION PROCEDURE
1 Check that the ECU connectors are securely connected to the ECU.
NO Connect the connector to the ECU.
YES
2 Is DTC output?
Check the DTC on page DI-505 .
YES Repair circuit indicated by the output code .
NO
3 Does ABS warning light go off?
YES Check for open or short circuit in harness and
connector between ECU-IG fuse and ECU (See

page IN-36 ).
NO
4 Check battery positive voltage.
PREPARATION:
Start the engine.
CHECK:
Check the battery positive voltage.
OK:
Voltage: 10 to 14 V
NG Check and repair the charging system.
OK
-DIAGNOSTICS ABS & VEHICLE STABILITY CONTROL (VSC) &
BRAKE ASSIST (BA) SYSTEM
DI-623
816A uthor: Date:
2004 LAND CRUISER (RM1071U)
5 Check operation of the ABS warning light.
In case of using the hand-held tester:
PREPARATION:
(a) Connect the hand-held tester to the DLC3.
(b) Turn the ignition switch ON and push the hand-held tester main switch ON.
(c) Select the ACTIVE TEST mode on the hand-held tester.
CHECK:
Check that ”ON” and ”OFF” of the ABS warning light can be shown on the combination meter by the hand-
held tester.
In case of not using the hand-held tester:
PREPARATION:
(a) Turn the ignition switch OFF.
(b) Disconnect the connector from the skid control ECU.
(c) Using a service wire, connect terminal WA of the skid control ECU harness side connector and body

ground.
(d) Turn the ignition switch ON.
CHECK:
Check that the ABS warning goes off.
OK Check and replace combination meter (See
page BE-2 ).
NG
6 Check for short circuit in harness and connector between combination meter
and skid control ECU, combination meter and DLC1 (See page
IN-36 ).
NG Repair or replace harness or connector.
OK
Check and replace skid control ECU.
F09989
ABS & BA & TRAC
& VSC ECU
V8
VSC Warmning Buzzer
Cowl Side J/B LH
ECU-IG1
BZA42
2
LB-W
2
1
2B
18
Buzzer
-DIAGNOSTICS ABS & VEHICLE STABILITY CONTROL (VSC) &
BRAKE ASSIST (BA) SYSTEM

DI-649
842A uthor: Date:
2004 LAND CRUISER (RM1071U)
Brake Warning and VSC Buzzer Circuit
CIRCUIT DESCRIPTION
The brake warning and VSC buzzer sounds while the accumulator pressure is abnormally low or an ab-
normality casing low fluid pressure occurs VSC is activated.
WIRING DIAGRAM
INSPECTION PROCEDURE
HINT:
Start the inspection from step 1 in case of using the hand-held tester and start from step 2 in case of not
using the hand-held tester.
1 Check operation of the brake warning and VSC buzzer.
PREPARATION:
(a) Connect the hand-held tester to the DLC3.
(b) Turn the ignition switch ON and push the hand-held tester main switch ON.
(c) Select the ACTIVE TEST mode on the hand-held tester.
CHECK:
Check that brake warning and VSC buzzer sounds ”ON” and ”OFF” with the hand-held tester.
OK Check and replace skid control ECU.
NG
DICAB-01
F02192
1
2(+) (-)
DI-650
-DIAGNOSTICS ABS & VEHICLE STABILITY CONTROL (VSC) &
BRAKE ASSIST (BA) SYSTEM
843A uthor: Date:
2004 LAND CRUISER (RM1071U)

2 Check brake warning and VSC buzzer.
PREPARATION:
Disconnect the brake warning and VSC buzzer connector.
CHECK:
Apply battery positive voltage to terminals 1 and 2 of the brake
warning and VSC buzzer connector. Check that the brake warn-
ing light comes on and the VSC buzzer sounds.
NG Replace brake warning and VSC buzzer.
OK
3 Check for open and short circuit in harness and connector between skid control
ECU and brake warning and VSC buzzer (See page IN-36 ).
NG Repair or replace harness or connector.
OK
Check and replace skid control ECU.
F16083
Cowl Side J/B RH
I18
Ignition SW
ABS & BA
& TRAC
& VSC Actuator
Cowl Side J/B LH
Engine Room J/B
F15
FL Block
AM2
P8
Parking
Brake
SW

Battery
Brake
BRLA43
5
Y-G
3A
11
3Q
6
SB
3E
4
MET
3Q
7
SB
C14
19
C12
10
C15
1
C14
20
2B
20
IX1
AA
A42
13

2Q
36
A40
LBL
2
Y-G
2K
R-W
27
AM2
2A
10
1B
9
EC
2
MAIN
6
IG2
J4
J/C
B-R
Combination Meter
1
W-R
B-G
BR
8
SB
SB

2E
2B
41
4
SB
7
PKB
R-W
1C
1
W-R
B-R
ABS & BA & TRAC
& VSC ECU
-DIAGNOSTICS ABS & VEHICLE STABILITY CONTROL (VSC) &
BRAKE ASSIST (BA) SYSTEM
DI-635
828A uthor: Date:
2004 LAND CRUISER (RM1071U)
BRAKE Warning Light Circuit
CIRCUIT DESCRIPTION
The BRAKE warning light lights up while the brake fluid is insufficient and EBD is abnormal.
WIRING DIAGRAM
DICA7-02
DI-636
-DIAGNOSTICS ABS & VEHICLE STABILITY CONTROL (VSC) &
BRAKE ASSIST (BA) SYSTEM
829A uthor: Date:
2004 LAND CRUISER (RM1071U)
INSPECTION PROCEDURE

1 Check parking brake switch circuit (See page BE-63 ).
NG Repair or replace parking brake switch circuit.
OK
2 Check brake fluid level warning switch circuit (See page BE-63 ).
NG Repair or replace brake fluid level warning
switch circuit.
OK
3 Is DTC output for ABS?
YES Repair circuit indicated by the output code.
NO
4 Do the warning lights other than BRAKE warning light come on?
YES Go to step 6.
NO
F00044
1
2
3
4
(+)
(-)
Continuity
12
34
1
2
3
4
Open
Continuity
-DIAGNOSTICS ABS & VEHICLE STABILITY CONTROL (VSC) &

BRAKE ASSIST (BA) SYSTEM
DI-637
830A uthor: Date:
2004 LAND CRUISER (RM1071U)
5 Check IG1 No. 1 relay.
PREPARATION:
Remove the IG1 No. 1 relay from the engine room J/B.
CHECK:
Check continuity between the IG1 No. 1 relay terminals listed
in the table below.
OK:
Terminals 3 and 4 Continuity
Terminals 1 and 2 Open
CHECK:
(a) Apply battery positive voltage between terminals 3 and 4.
(b) Check continuity between terminals.
OK:
Terminals 1 and 2 Continuity
NG Replace IG1 No. 1 relay.
OK
Check for open circuit in harness and connector between IG1 No. 1 relay and combination meter
(See page IN-36 ).
6 Check that the ECU connectors are securely connected to the ECU.
NO Connect the connector to the ECU.
YES
DI-638
-DIAGNOSTICS ABS & VEHICLE STABILITY CONTROL (VSC) &
BRAKE ASSIST (BA) SYSTEM
831A uthor: Date:
2004 LAND CRUISER (RM1071U)

7 Check BRAKE warning light.
Check if that the open circuit in the combination meter circuit (See page BE-58 ).
NG Repair brake warning light bulb or combination
meter assembly.
OK
8 Check for short circuit in harness and connector between brake warning light and skid
control ECU (See page IN-36 ).
NG Repair or replace harness or connector.
OK
Check and repair skid control ECU.
DI-528
-DIAGNOSTICS ABS & VEHICLE STABILITY CONTROL (VSC) &
BRAKE ASSIST (BA) SYSTEM
721A uthor: Date:
2004 LAND CRUISER (RM1071U)
DTC C0226 / 21 - C0256 / 24 ABS Solenoid Circuit
CIRCUIT DESCRIPTION
This solenoid goes on when signals are received from the ECU and controls the pressure acting on the wheel
cylinders thus controlling the braking force.
DTC No. DTC Detecting Condition Trouble Area
C0226 / 21
Open or short in SFRH or SFRR circuit continues for 0.015
sec. or more.
L Hydraulic brake booster
L SFRH or SFRR circuit
C0236 / 22
Open or short in SFLH or SFLR circuit continues for 0.015
sec. or more.
L Hydraulic brake booster
L SFLH or SFLR circuit

C0246 / 23
Open or short in SRRH or SRRR circuit continues for 0.015
sec. or more.
L Hydraulic brake booster
L SRRH or SRRR circuit
C0256 / 24
Open or short in SRLH or SRLR circuit continues for 0.015
sec. or more.
L Hydraulic brake booster
L SRLH or SRLR circuit
DIC95-01
F17705
SFLH
SFLR
SFRH
SFRR
SRLH
SRLR
SRRH
SRRR
AST
BS
Batter
FL Block
MAIN
ABS No.1
ABS
SOL Relay
Engine Room R/B
ABS & BA & TRAC

& VSC Actuator
ABS & BA & TRAC
& VSC ECU
SFLH
SFLR
SFRH
SFRR
SRLH
SRLR
SRRH
SRRR
AST
A39
8
A41
21
A44
16
A39
A39
A39
A39
A39
A39
A39
A38
A37
A41
A41
A41

A41
A41
7
10
9
4
3
2
1
1
4
7
8
7
1
9
8
6
19
1
A44
A44
A44
A44
Y
B-Y
LG
B-W
R-W
R-Y

G-Y
P
B-R
L-B
B-O
R-G
W
1
1
1
1
1
1
1
1
3
6
4
2
Engine Room J/B and
Engine Room R/B
1C
B-R
F15
2
SR
R1+
-DIAGNOSTICS ABS & VEHICLE STABILITY CONTROL (VSC) &
BRAKE ASSIST (BA) SYSTEM
DI-529

722A uthor: Date:
2004 LAND CRUISER (RM1071U)
WIRING DIAGRAM
F02855
LOCK
A43
A45
4
1
2
3
4
10
9
8
7
DI-530
-DIAGNOSTICS ABS & VEHICLE STABILITY CONTROL (VSC) &
BRAKE ASSIST (BA) SYSTEM
723A uthor: Date:
2004 LAND CRUISER (RM1071U)
INSPECTION PROCEDURE
1 Check hydraulic brake booster solenoid.
PREPARATION:
Disconnect the 2 connectors from the hydraulic brake booster.
CHECK:
Check continuity between terminals A43 - 4 and A45 - 1, 2, 3,
4, 7, 8, 9 and 10 of the hydraulic brake booster connector.
OK:
Continuity

HINT:
Resistance of each solenoid at 20 °C (68 °F):
SFRH, SFLH, SRRH, SRLH: 6.95 to 7.45 Ω
SFRR, SFLR, SRRR, SRLR: 2.00 to 2.40 Ω
NG Replace hydraulic brake booster.
OK
2 Check for open and short circuit in harness and connector between skid control
ECU and actuator (See page IN-36 ).
NG Repair or replace harness or connector.
OK
If the same code is still output after the DTC is deleted, check the contact condition of each con-
nection. If the connections are normal, the ECU may be defective.
-DIAGNOSTICS ABS & VEHICLE STABILITY CONTROL (VSC) &
BRAKE ASSIST (BA) SYSTEM
DI-531
724A uthor: Date:
2004 LAND CRUISER (RM1071U)
DTC C0278 / 11, C0279 / 12 ABS Solenoid Relay Circuit
CIRCUIT DESCRIPTION
This relay supplies power to each ABS solenoid. After the ignition switch is turned ON, if the initial check is
OK, the relay goes on.
DTC No. DTC Detecting Condition Trouble Area
C0278 / 11
Conditions 1. and 2. continue for 0.2 sec. or more:
1. ECU terminal IG1 voltage is 9.5 V to 17.0 V and the
solenoid relay is ON, however, the contact point of the
solenoid relay is OFF.
2. With solenoid relay ON, ECU terminal IG1 voltage be-
comes 9.5 V or less and the contact point of the sole-
noid relay does not become ON.

L ABS solenoid relay
L ABS solenoid relay circuit
C0279 / 12
Immediately after ECU terminal IG1 becomes ON, and
solenoid relay is OFF, however, when the condition that
the solenoid relay due to the contact point is ON continues
for 0.2 sec. or more.
WIRING DIAGRAM
Refer to DTC C0226/21 on page DI-528 .
INSPECTION PROCEDURE
HINT:
Start the inspection from step 1 in case of using the hand-held tester and start from step 2 in case of not
using the hand-held tester.
1 Check ABS solenoid relay operation.
PREPARATION:
(a) Connect the hand-held tester to the DLC3.
(b) Turn the ignition switch ON and push the hand-held tester main switch ON.
(c) Select the ACTIVE TEST mode on the hand-held tester.
CHECK:
Check the operation sound of the ABS solenoid relay when operating it with the hand-held tester.
OK:
The operation sound of the ABS solenoid relay should be heard.
OK Go to step 6.
NG
DIC98-02
F04447
(-)
(+)
1
2

Engine Room J/B
F00042
13
4
6
Open
(+)
(-)
123
4
4
56
1
2
3
2
5
6
5
Continuity
Continuity
Continuity
Open
DI-532
-DIAGNOSTICS ABS & VEHICLE STABILITY CONTROL (VSC) &
BRAKE ASSIST (BA) SYSTEM
725A uthor: Date:
2004 LAND CRUISER (RM1071U)
2 Check voltage between terminals 1 and 2 of engine room J/B (for ABS solenoid
relay).

PREPARATION:
Remove the ABS solenoid relay from the engine room J/B.
CHECK:
Measure the voltage between terminals 1 and 2 of the engine
room J/B (for ABS solenoid relay).
OK:
Voltage: 10 to 14 V
NG Check and repair harness or connector.
OK
3 Check ABS solenoid relay.
CHECK:
Check continuity between each terminal of the ABS solenoid
relay.
OK:
Terminals 4 and 6
Continuity
(Reference value 80 Ω)
Terminals 2 and 3 Continuity
Terminals 1 and 3 Open
CHECK:
(a) Apply battery positive voltage between terminals 4 and 6.
(b) Check continuity between each terminal of the ABS sole-
noid relay.
OK:
Terminals 2 and 3 Open
Terminals 1 and 3 Continuity
NG Replace ABS solenoid relay.
OK
F02839
ECU

ABS Solenoid
Relay
Brake
Booster
3
4
AST
A43
A44
1
-DIAGNOSTICS ABS & VEHICLE STABILITY CONTROL (VSC) &
BRAKE ASSIST (BA) SYSTEM
DI-533
726A uthor: Date:
2004 LAND CRUISER (RM1071U)
4 Check continuity between terminals 3 of ABS solenoid relay and terminal AST of
skid control ECU.
CHECK:
Check continuity between terminal 3 of the ABS solenoid relay
and terminal AST of the skid control ECU.
OK:
Continuity
HINT:
There is resistance of 33 ± 3 Ω between terminals 4 of connec-
tor A43 and terminal 1 of connector A44.
NG Repair or replace harness, connector or hy-
draulic brake booster.
OK
5 Check for open and short circuit in harness and connector between ABS sole-
noid relay and skid control ECU (See page IN-36 ).

NG Repair or replace harness or connector.
OK
If the same code is still output after the DTC is deleted, check the contact condition of each con-
nection. If the connections are normal, the ECU may be defective.
DI-534
-DIAGNOSTICS ABS & VEHICLE STABILITY CONTROL (VSC) &
BRAKE ASSIST (BA) SYSTEM
727A uthor: Date:
2004 LAND CRUISER (RM1071U)
6 Check for open circuit in harness and connector between AST of hydraulic brake
booster and AST of skid control ECU (See page IN-36 ).
NG Repair or replace harness or connector.
OK
Replace hydraulic brake booster or skid con-
trol ECU.
-DIAGNOSTICS ABS & VEHICLE STABILITY CONTROL (VSC) &
BRAKE ASSIST (BA) SYSTEM
DI-535
728A uthor: Date:
2004 LAND CRUISER (RM1071U)
DTC C1201 / 51 Engine Control System Malfunction
CIRCUIT DESCRIPTION
If trouble occurs in the engine control system, the ECU prohibits TRAC and VSC control.
DTC No. DTC Detecting Condition Trouble Area
C1201 / 51
Conditions 1. and 2. continue for 5 sec.:
1. Engine speed: 500 rpm or more.
2. A trouble signal in the engine control system is input.
Engine control system
INSPECTION PROCEDURE

1 Check the DTC for the engine (See page DI-3 ).
*
1
Repair engine control system according to the
output code.
*
2
Check for ECM connected to malfunction in-
dicator light.
*
1
: Output NG code
*
2
: Malfunction indicator light remains ON
DIC99-01
F13732
ENG-
ENG+
TRC+
TRC-
24
22
14
16
A42
ECM
ENG+
ENG-
TRC+

TRC-
ABS & BA & TRAC
& VSC ECU
E9
A42
A42
24
A42
R
G
Y
L
IG4
IG4
IG4
IG4
12
13
1
2
R
G
Y
L
30
25
31
E9
E9
E9

DI-536
-DIAGNOSTICS ABS & VEHICLE STABILITY CONTROL (VSC) &
BRAKE ASSIST (BA) SYSTEM
729A uthor: Date:
2004 LAND CRUISER (RM1071U)
DTC C1203 / 53 ECM Communication Circuit Malfunc-
tion
CIRCUIT DESCRIPTION
The circuit is used to send TRAC & VSC control information from the skid control ECU to the ECM (TRC+,
TRC-), and engine control information from the ECM to the skid control ECU (ENG+, ENG-).
DTC No. DTC Detecting Condition Trouble Area
C1203 / 53
Either of the following 1. or 2. continues for 5 sec.:
1. ECU IG1 terminal voltage is 9.5 V to 17.0 V and data
transmission to the ECM is impossible.
2. ECU IG1 terminal voltage is 9.5 V to 17.0 V, engine
speed is 500 rpm or more or vehicle speed is 60 km/h
(36 mph) or more and data receiving from the ECM is
impossible.
L TRC+ or TRC- circuit
L ENG+ or ENG- circuit
L ECM
WIRING DIAGRAM
DIC9A-01