Page 793 of 3115

F17754
ABS & BA & TRAC
& VSC ECU
ECM
J/B No.5
NEO A427
W
5D 12
5
5C E9W
NEO17
- DIAGNOSTICSABS & VEHICLE STABILITY CONTROL (VSC) &
BRAKE ASSIST (BA) SYSTEMDI-541
734 Author: Date:
2004 LAND CRUISER (RM1071U)
DTC C1224 / 44 NE Signal Circuit
CIRCUIT DESCRIPTION
The skid control ECU receives engine revolution speed signals (NE signals) from the ECM.
DTC No.DTC Detecting ConditionTrouble Area
C1224 / 44
When either of the following 1. or 2. is detected:
1. At vehicle speed of 19 mph (30 km/h) or more, and
when data received from the ECM is in normal condition,
and open or short circuit for engine revolution signal
circuit continues for 10 sec. or more.
2. While TRAC is operating, the conditions that open or
short circuit in engine revolution signal circuit is de-
tected, main throttle opening degree is 0 and IDL switch
is OFF continue for 0.24 sec. or more.
NEO circuit
ECM
Skid control ECU
WIRING DIAGRAM
INSPECTION PROCEDURE
1 Check for open and short circuit in harness and connector between terminal
NEO of skid control ECU and terminal NEO of ECM (See page
IN-36).
NG Repair or replace harness and connector.
OK
DIC9G-01
Page 794 of 3115
F02807
ON
NEO
(+)
(-)
F03007
(Reference)
10 to 14 V
Below 1 V
DI-542- DIAGNOSTICSABS & VEHICLE STABILITY CONTROL (VSC) &
BRAKE ASSIST (BA) SYSTEM
735 Author: Date:
2004 LAND CRUISER (RM1071U)
2 Check voltage between terminal NEO of skid control ECU and body ground.
PREPARATION:
Remove the skid control ECU with connectors still connected.
CHECK:
(a) Turn the ignition switch ON.
(b) Measure voltage between terminal NEO of the skid con-
trol ECU and body ground for the engine conditions be-
low.
OK:
Engine conditionVoltage
OFF (IG ON)10 to 14 V or below 1 V
ON (Idling)10 to 14 V e below 1 V (Pulse)
NG Check and replace skid control ECU or ECM.
OK
If the same codes are still output after the DTC is deleted, check the contact condition of each
connection.
Page 795 of 3115
- DIAGNOSTICSABS & VEHICLE STABILITY CONTROL (VSC) &
BRAKE ASSIST (BA) SYSTEMDI-543
736 Author: Date:
2004 LAND CRUISER (RM1071U)
DTCC1225 / 25 to C1228 / 28TRAC & VSC Solenoid Circuit
CIRCUIT DESCRIPTION
The TRAC & VSC solenoid operates in accordance with signals from the ECU and raises the fluid pressure
in and releases it from the brake cylinders.
DTC No.DTC Detecting ConditionTrouble Area
C1225 / 25Open or short in SA1 circuit continues for 0.015 sec. or
more.Hydraulic brake booster
SA1 circuit
C1226 / 26Open or short in SA2 circuit continues for 0.015 sec. or
more.Hydraulic brake booster
SA2 circuit
C1227 / 27Open or short in SA3 circuit continues for 0.015 sec. or
more.Hydraulic brake booster
SA3 circuit
C1228 / 28Open or short in STR circuit continues for 0.015 sec. or
more.Hydraulic brake booster
STR circuit
DIC9H-02
Page 796 of 3115
F17708
ABS & BA & TRAC
& VSC ECU ABS & BA & TRAC
& VSC Actuator
Engine Room R/B
Engine Room J/B and
Engine Room R/B
FL Block
BatterySTR
SA3
SA2
SA1
SR A41
A41
A41
A41
A41
R1+
A411192 3 4 5
G-Y
G-W
B
G A396
5
A39
11
A39
12
A39
A374 STR
SA3
SA2
SA1
BSL-B
1 ABS SOL Relay
1
1131
4 6
1
1 1C1 ABS No.1
F15 MAINB-GB-RP G-Y
2
2 B-G DI-544
- DIAGNOSTICSABS & VEHICLE STABILITY CONTROL (VSC) &
BRAKE ASSIST (BA) SYSTEM
737 Author: Date:
2004 LAND CRUISER (RM1071U)
WIRING DIAGRAM
Page 797 of 3115
F02857
LOCK
45
6
11 12
A43
A45
- DIAGNOSTICSABS & VEHICLE STABILITY CONTROL (VSC) &
BRAKE ASSIST (BA) SYSTEMDI-545
738 Author: Date:
2004 LAND CRUISER (RM1071U)
INSPECTION PROCEDURE
1 Check TRAC & VSC solenoid.
PREPARATION:
Disconnect the 2 connectors from the hydraulic brake booster.
CHECK:
Check continuity between terminals A43 - 4 and A45 - 5, 6, 11
and 12 of the hydraulic brake booster.
OK:
Continuity
HINT:
Resistance of each solenoid at 20 °C (68 °F):
SA1, SA2, STR: 4.05 to 4.55 W
SA3: 6.95 to 7.45 W
NG Replace hydraulic brake booster.
OK
2 Check for open and short circuit in harness and connector between skid control
ECU and hydraulic brake booster (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 798 of 3115

DI-546- DIAGNOSTICSABS & VEHICLE STABILITY CONTROL (VSC) &
BRAKE ASSIST (BA) SYSTEM
739 Author: Date:
2004 LAND CRUISER (RM1071U)
DTCC1231 / 31, C1335 / 35Steering Angle Sensor Circuit
CIRCUIT DESCRIPTION
DTC No.DTC Detecting ConditionTrouble Area
C1231 / 31
Detection of any of the conditions 1. through 3.:
1. When the condition that ECU terminal IG1 voltage is 9.5
V or more, and does not receive data from steering
angle sensor continues for 1 sec. or more.
2. When the steering angle sensor value changes by 360°
or more with SSC signal from steering angle sensor
remaining ON or OFF.
3. When the condition that difference between the steering
angle value at edge occurring in SSC signal and the
value at edge occurring in SSC signal after turning the
steering wheel one-turn is out of the range from 355.5°
- 364.5° occurs 10 times or more.
Steering angle sensor
Steering angle sensor circuit
C1335 / 35
When the ECU IG1 terminal voltage is 9.5 V or more, data
transmission from the steering angle sensor is impossible
for 1 sec. or more.Steering angle sensor
Steering angle sensor circuit
DIC9J-02
Page 799 of 3115
F17753
ABS & BA & TRAC
& VSC ECU C17
Combination Meter
B-R B-W14
A43
23
A43
1
F16 SS1+
SS1-
IG1
ESS3
11
1
2W
GWW
G
G
6II3 27
IG1 15
IG1 16
IH2II3
L-B
W-B SB2C1 39
16
37 2E
2E 2Q
3
215B-GSS1+
SS1-
Battery
IFIF
2Q Cowl Side J/B LHIH29 42IG1
AM1
ALTFL Block AM1
ECU-IG1 26
23Cowl Side J/B LH
IG1 No.2 Relay
I18
Ignition SW SB
J/B No.2
- DIAGNOSTICSABS & VEHICLE STABILITY CONTROL (VSC) &
BRAKE ASSIST (BA) SYSTEMDI-547
740 Author: Date:
2004 LAND CRUISER (RM1071U)
WIRING DIAGRAM
Page 800 of 3115

F17609
ESS (-)
IG (+)
BAT (+)
DI-548- DIAGNOSTICSABS & VEHICLE STABILITY CONTROL (VSC) &
BRAKE ASSIST (BA) SYSTEM
741 Author: Date:
2004 LAND CRUISER (RM1071U)
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 output value of the steering angle sensor.
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 DATALIST mode on the hand-held tester.
CHECK:
Check that the steering wheel turning angle value of the steering angle position sensor displayed on the
hand-held tester is changing when turning the steering wheel.
HINT:
After certifying ºZeroº point calibration of the steering angle sensor (Speed: 21 mph (35 km/h), driving straight
ahead for 10 sec. or more), the value will change.
OK:
Steering wheel turning angle value must be changing.
OK Go to step 5.
NG
2 Check input voltage of the steering angle sensor.
PREPARATION:
Remove the column lower cover.
CHECK:
(a) Turn the ignition switch ON.
(b) Measure voltage between terminals 1 and 2, 2 and 9 of
the combination switch wire harness side connector.
OK:
Voltage: 10 to 14 V
NG Check and replace harness and connector.
OK