Page 785 of 3115
F02839
ECU ABS Solenoid
Relay
Brake
Booster
3
4
AST
A43
A44
1
- DIAGNOSTICSABS & VEHICLE STABILITY CONTROL (VSC) &
BRAKE ASSIST (BA) SYSTEMDI-533
726 Author: 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 W 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.
Page 786 of 3115
DI-534- DIAGNOSTICSABS & VEHICLE STABILITY CONTROL (VSC) &
BRAKE ASSIST (BA) SYSTEM
727 Author: 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.
Page 787 of 3115
- DIAGNOSTICSABS & VEHICLE STABILITY CONTROL (VSC) &
BRAKE ASSIST (BA) SYSTEMDI-535
728 Author: 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 ConditionTrouble 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).
*1Repair 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
Page 788 of 3115

F13732
ENG- ENG+
TRC+
TRC-24
22 14
16 A42 ECM
ENG+
ENG-
TRC+
TRC- ABS & BA & TRAC
& VSC ECU
E9
A42
A4224
A42 R
G
Y
L IG4
IG4
IG4
IG412
13
1
2 R
G
Y
L 30
25
31E9
E9
E9 DI-536
- DIAGNOSTICSABS & VEHICLE STABILITY CONTROL (VSC) &
BRAKE ASSIST (BA) SYSTEM
729 Author: 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 ConditionTrouble 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.
TRC+ or TRC- circuit
ENG+ or ENG- circuit
ECM
WIRING DIAGRAM
DIC9A-01
Page 789 of 3115
F17613
Normal Signal Waveform
1 V /
Division
2 m/s / DivisionGND
- DIAGNOSTICSABS & VEHICLE STABILITY CONTROL (VSC) &
BRAKE ASSIST (BA) SYSTEMDI-537
730 Author: Date:
2004 LAND CRUISER (RM1071U)
INSPECTION PROCEDURE
1 Check skid control ECU communication.
(REFERENCE) INSPECTION USING OSCILLOSCOPE
PREPARATION:
(a) Remove the skid control ECU.
(b) Connect the oscilloscope to each of terminal ENG+ or
TRC+ and GND of the skid control ECU.
CHECK:
Start the engine, and check the signal waveform.
NG Check and replace skid control ECU.
OK
2 Check for open and short circuit in harness and connector between each of ter-
minals ENG+, ENG-, TRC+, TRC- of skid control ECU and ECM (See page
IN-36).
NG Repair or replace harness or connector.
OK
Check and replace ECM.
Page 790 of 3115
F17752
ABS & BA & TRAC
& VSC ECU
Yaw Rate Sensor
ShieldedGL1
GL2
YD
VYS
YAW
GYAW
YSS A43
1827 289 191022
G
Y
L
W
R 4
2
6
8
1
5A43
A43
A43
A43
A43
A42 IG4
IG4
IG4
IG4
IG4
IG4
IG416
17
21
19
20
18
22
ShieldedG
Y
L
B
W
R GL1
GL2
YD
VYS
YAW 2
GYAWB DI-538
- DIAGNOSTICSABS & VEHICLE STABILITY CONTROL (VSC) &
BRAKE ASSIST (BA) SYSTEM
731 Author: Date:
2004 LAND CRUISER (RM1071U)
DTC C1210 / 36 Zero Point Calibration of Yaw Rate
Sensor Undone
CIRCUIT DESCRIPTION
DTC No.DTC Detecting ConditionTrouble Area
C1210 / 36
When either of the following 1. or 2. is detected:
1. After battery terminal was connected, when the shift
lever was moved to other than P position within 15 sec.
soon after ECU terminal IG1 becomes ON for the first
time.
2. When the yaw rate sensor zero point recorded in ECU is
deleted.
Yaw rate sensor
Yaw rate sensor circuit
PNP switch circuit (P position)
WIRING DIAGRAM
DIC9C-01
Page 791 of 3115

- DIAGNOSTICSABS & VEHICLE STABILITY CONTROL (VSC) &
BRAKE ASSIST (BA) SYSTEMDI-539
732 Author: Date:
2004 LAND CRUISER (RM1071U)
INSPECTION PROCEDURE
1 Check whether zero point calibration of yaw rate sensor has been done or not.
PREPARATION:
Shift the shift lever in the P position and turn the ignition switch ON. Repeat connecting and releasing Ts
and E
1 terminals of the DLC1 4 times or more for 8 sec. After that do not move the vehicle for 15 sec. or more.
CHECK:
Check that theºVSC TRACº warning light and ºVSC OFFº indicator light light up for 15 sec.
OK No problem.
NG
2 Check for open and short circuit in harness and connector between PNP switch
(P position) and skid control ECU and ECM (See page IN-36).
NG Repair or replace harness or connector.
OK
3 Check for open and short circuit in harness and connector between yaw rate
sensor and skid control ECU (See page IN-36).
NG Repair or replace harness or connector.
OK
4 Check yaw rate sensor (See page DI-553).
NG Replace yaw rate sensor.
OK
Check and replace skid control ECU.
Page 792 of 3115
DI-540- DIAGNOSTICSABS & VEHICLE STABILITY CONTROL (VSC) &
BRAKE ASSIST (BA) SYSTEM
733 Author: Date:
2004 LAND CRUISER (RM1071U)
DTC C1223 / 43 ABS Control System Malfunction
CIRCUIT DESCRIPTION
DTC No.DTC Detecting ConditionTrouble Area
C1223 / 43ABS control system is abnormal.ABS control system
INSPECTION PROCEDURE
1 Check the DTC for the ABS (See page DI-505).
*1Repair ABS control system according to the
code output.
*
2
Check for ECU connected to malfunction in-
dicator light.
*
1: Output NG code
*
2: Malfunction indicator light remains ON
DIC9E-01