2003 LEXUS LS430 brake sensor

1.DIAGNOSIS
FL+ (S42-18) - FL-
(S42-4)P -VFront LH wheel speed
signal inputIG switch ON, slowly turn
left front wheelAC generation
RL+ (S42-20) - RL-
(S42-6)BR-W -
BRRear LH wheel speed signal
inputIG switch ON, slowly turn
left rear wheelAC generation
TS (S42-24) -GND
(S42-1, 32)B - BR,
W-BSensor check inputIG switch ON11 to 14 V
STP (S42-27) -
GND (S42-1, 32)G-W - BR,
W-BStop lamp switch inputStop light switch ON
(Brake pedal pushed)8 to 14 V
STP (S42-27) -
GND (S42-1, 32)G-W - BR,
W-BStop lamp switch inputStop light switch OFF
(Brake pedal released)Below 1.5 V
PKB (S42-28) -
GND (S42-1, 32)B-L - BR,
W-BParking brake switch inputIG switch ON, parking
brake switch ONBelow 1.5 V
PKB (S42-28) -
GND (S42-1, 32)B-L - BR,
W-BParking brake switch inputIG switch ON, parking
brake switch OFF11 to 14 V
BZ (S42-30) -GND
(S42-1, 32)W-R - BR,
W-BBuzzer outputIG switch ON, VSC
buzzer soundsBelow 1.0 <-->
11 to 14 V
BZ (S42-30) -GND
(S42-1, 32)W-R - BR,
W-BBuzzer outputIG switch ON, VSC
buzzer does not sound11 to 14 V
+BS (S42-31) -
GND (S42-1, 32)B - BR,
W-BSolenoid relay power supplyAlways11 to 14 V
FRO (S42-37) -
GND (S42-1, 32)Y-R - BR,
W-BFront RH wheel speed
signal outputVehicle drives at approx.
12 mph (20 km/h)Pulse generation
FLO (S42-38) -
GND (S42-1, 32)Y-B - BR,
W-BFront LH wheel speed
signal outputVehicle drives at approx.
12 mph (20 km/h)Pulse generation
INIT (S42-41) -
GND (S42-1, 32)GR-R -
BR, W-BThe pressure warning
standardization switch InputIG switch ON, The
pressure warning switch
ON
Below 1.5 V
INIT (S42-41) -
GND (S42-1, 32)GR-R -
BR, W-BThe pressure warning
standardization switch InputIG switch ON, The
pressure warning switch
OFF
11 to 14 V
WFSE (S42-42) -
GND (S42-1, 32)LG-B -
BR, W-BWFSE inputIG switch ON11 to 14 V
CSW (S42-43) -
GND (S42-1, 32)Y-G - BR,
W-BTRAC cut switch InputIG switch ON, TRAC
OFF switch is off11 to 14 V
CSW (S42-43) -
GND (S42-1, 32)Y-G - BR,
W-BTRAC cut switch InputIG switch ON, TRAC
OFF switch is onBelow 1.5 V
R+ (S42-45) -GND
(S42-1, 32)R-W - BR,
W-BPower supply for motor
relayIG switch ON11 to 14 V
IG1 (S42-46) -GND
(S42-1, 32)B-R - BR,
W-BIG1 power supplyIG switch ON11 to 14 V

xcirc: Light ON
-: Light OFF
The DTCs are simultaneously stored in memory. The DTCs can be read by connecting the hand-
held tester.
This system has a sensor signal check function (Test Mode).
The DTC can be read by connecting the SST between terminals TS and CG of DLC3 and observing the
blinking of the ABS warning light and VSC information, or by connecting the hand-held tester.
1.DTC CHECK (USING HAND-HELD TESTER)
Item / Trouble AreaABSEBDAssist)TRACVSC
ABS Warning Light000--
Brake Warning Light-0---
TRAC OFF Indicator Light00000
VSC Warning (Multi Information
Display)00000

HINT:
If a malfunction code is displayed during the DTC check, check the circuit indicated by the table below.
DIAGNOSTIC TROUBLE CODE CHART
SMF (BA-SOL)Turns TRAC solenoid SMF (BA-SOL)
ON / OFFOperation of solenoid (clicking sound)
can be heard
SMRTurns TRAC solenoid SMR ON / OFFOperation of solenoid (clicking sound)
can be heard
SOL RELAYTurns ABS solenoid relay ON / OFFOperation of solenoid (clicking sound)
can be heard
ABS MOT RELAYTurns ABS motor relay ON / OFFOperation of solenoid (clicking sound)
can be heard
ABS WARN LIGHTTurns ABS warning light ON / OFFObserve combination meter
VSC WARN LIGHTTurns VSC warning light ON / OFFObserve combination meter
VSC / TRC OFF INDTurns VSC / TRC OFF indicator ON /
OFFObserve combination meter
SLIP INDI LIGHTTurns SLIP indicator light ON / OFFObserve combination meter
BRAKE WRN LIGHTTurns BRAKE warning light ON / OFFObserve combination meter
VSC / BR WARN
BUZTurns VSC / BRAKE warning buzzer
ON / OFFBuzzer can be heard
STP LIGHT RELAYTurns stop light ON / OFFStop light come on
DTCDescription
DTC C0200/31, C0205/32RIGHT/LEFT FRONT SPEED SENSOR
DTC C0210/33, C0215/34RIGHT/LEFT REAR SPEED SENSOR
DTC C0226/21, C0236/22, C0246/23,
C0256/24, C1225/25
SFR/SFL/SRR/SRL/SM SOLENOID CIRCUIT
DTC C0273/13, C0274/14, C1361/91OPEN CIRCUIT IN ABS MOTOR RELAY CIRCUIT,
B+ SHORT CIRCUIT IN ABS MOTOR RELAY
CIRCUIT, SHORT CIRCUIT IN ABS MOTOR FAIL
SAFE RELAY CIRCUIT
DTC C0278/11, C0279/12OPEN/SHORT CIRCUIT IN ABS SOLENOID
RELAY CIRCUIT
DTC C1201/51ENGINE CONTROL SYSTEM MALFUNCTION
DTC C1203/53ECM COMMUNICATION CIRCUIT
MALFUNCTION
DTC C1210/36, C1336/39ZERO POINT CALIBRATION OF YAW
RATE/DECELERATION SENSOR UNDONE
DTC C1223/43ABS CONTROL SYSTEM MALFUNCTION
DTC C1231/31MALFUNCTION IN STEERING ANGLE SENSOR
CIRCUIT

DTC chart of ABS:
DTC C1232/32, C1234/34, C1243/43,
C1244/44, C1245/45, C1381/97
MALFUNCTION IN DECELERATION/YAW RATE
SENSOR, OPEN OR SHORT IN DECELERATION
SENSOR CIRCUIT, MALFUNCTION IN POWER
SUPPLY VOLTAGE YAW/DECELERATION
SENSOR
DTC C1235/35, C1236/36, C1238/38,
C1239/39
FOREIGN MATTER IS ATTACHED ON TIP OF
RIGHT/LEFT FRONT/REAR SENSOR
DTC C1241/41LOW BATTERY POSITIVE VOLTAGE
DTC C1246/46MALFUNCTION IN MASTER CYLINDER
PRESSURE SENSOR
DTC C1249/49OPEN CIRCUIT IN STOP LIGHT SWITCH CIRCUIT
DTC C1251/51PUMP MOTOR IS LOCKED/OPEN CIRCUIT IN
PUMP MOTOR GROUND
DTC C1267/67Brake Pedal Load Sensing Switch

NORMAL CODE DESCRIPTION
B: REPAIR ENGINE CONTROL SYSTEM ACCORDING TO DTC OUTPUT
A: REPLACE ECM
CIRCUIT DESCRIPTION
DTC DETECTING CONDITION DESCRIPTION
INSPECTION PROCEDURE
REPLACE ECM
CIRCUIT DESCRIPTION
Brake actuator receives signals from the yaw rate sensor (deceleration sensor) via CAN communication system.
Yaw rate sensor has the built-in deceleration sensor. If there is trouble in the bus lines between yaw rate sensor
(deceleration sensor) and CAN communication system, the DTC codes U0123/62 (yaw rate sensor
communication trouble) and U0124/95 (Deceleration sensor communication trouble) are output. The DTC is
also output when the calibration has not been completed.
Fig. 74: DTC C1210/36 And DTC C1336/39 Detecting Condition And Trouble Area

Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
Normal CodeA
Malfunction CodeB
DTC No.DTC Detecting ConditionTrouble Area
C1203/53Engine, drive source and destination variations that are sent from the
engine control ECU do not match the ones of the skid control ECU.ECM

c. Select the DATA LIST mode on the hand-held tester.
MEASUREMENT ITEM / RANGE (DISPLAY) DESCRIPTION
d. Check that the brake fluid pressure value of the master cylinder pressure sensor observed in the
hand held tester changes when the brake pedal is depressed.
OK: Go to next step
When the pedal is depressed, displayed voltage on the hand-held tester increases.
NG: Go to step 2
OK: REPLACE ABS & TRACTION ACTUATOR ASSY (SEE REPLACEMENT
)
2.INSPECT SKID CONTROL ECU TERMINAL VOLTAGE (STP TERMINAL)
a. Disconnect the skid control ECU connector.
b. Measure the voltage according to the value (s) in the table below.
Standard:
TESTER CONNECTION SPECIFIED CONDITION
NG: CHECK AND REPLACE STOP LIGHT SWITCH CIRCUIT
OK: REPLACE ABS & TRACTION ACTUATOR ASSY (SEE REPLACEMENT
)
ItemMeasurement Item / Range (Display)Normal Condition
MAS CYL PRS
1Master cylinder pressure sensor 1 reading /
min.: 0 V, max.: 5 VWhen brake pedal is released:
0.3 to 0.9V
Tester ConnectionSwitch ConditionSpecified Condition
S42-27 (STP) - Body groundBrake pedal depressed8 to 14V
S42-27 (STP) - Body groundBrake pedal releasedBelow 1 V

Fig. 120: Identifying Suspension Control ECU Connector Terminals
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
NG: REPAIR OR REPLACE HARNESS OR CONNECTOR
OK: REPLACE SUSPENSION CONTROL ECU (SEE REPLACEMENT
)
CIRCUIT DESCRIPTION
The speed sensors monitors the speed of the wheels, and sends an appropriate speed signals to the suspension
control ECU through the brake actuator assy (skid control ECU).
If trouble occurs in either the right rear speed sensor or left rear speed sensor, DTC (C1776) is output.

Replace the RH side by using the same procedures as for the LH side.
The procedures listed below are for the LH side.
1.REMOVE FRONT WHEEL
2.DISCONNECT SKID CONTROL SENSOR WIRE
a. Disconnect the skid control sensor connector.
Fig. 125: Disconnecting Skid Control Sensor Connector

Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
3.SEPARATE FRONT DISC BRAKE CALIPER ASSY LH (SEE OVERHAUL
)
4.REMOVE FRONT DISC (SEE COMPONENTS
)
5.REMOVE FRONT AXLE HUB SUB-ASSY LH (SEE REPLACEMENT
)
6.REMOVE SKID CONTROL SENSOR FRONT
a. Mount the front axle hub sub-assy LH on a soft jaw vise.
b.Using<0003004400030053004c005100030053005800510046004b00030044005100470003004b00440050005000480055000f000300470055004c00590048000300520058005700030057004b00480003001500030053004c005100560003004400510047000300
550048005000520059004800030057004b0048000300150003[attachments from SST.