air condition LEXUS LS430 2003 Factory User Guide

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

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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

HINT:
This DTC is output when the VSC system detects a malfunction in the ABS system.
When DTC C1223/43 is memorized, there is no malfunction in the skid control ECU.
CIRCUIT DESCRIPTION
DTC DETECTING CONDITION DESCRIPTION
INSPECTION PROCEDURE
1.CHECK DTC (FOR ABS SYSTEM)
a. Clear the DTC (see DTC CHECK/CLEAR
).
b. Turn the ignition switch to the ON position.
c. Check that the same DTC is recorded (see DTC CHECK/CLEAR
).
OK: Go to next step
The same DTC is recorded.
NG: PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS
TABLE
HINT:
It is suspect that the DTCs output was caused by the poor connection of the connector terminal.
OK REPAIR CIRCUIT INDICATED BY OUTPUT DTC
CIRCUIT DESCRIPTION
The steering angle sensor signal is sent to the skid control ECU through the CAN communication system. When
there is a malfunction in the communication, it will be detected by the diagnosis function.
DTC No.DTC Detecting ConditionTrouble Area
C1223/43Malfunction in ABS control systemABS control system

When U0121/94, U0123/62, U0124/95 or U0126/63 are output together with C1231/31, inspect and
repair the trouble areas indicated by U0121/94, U0123/62, U0124/95 or U0126/63 first.
When the speed sensor or the yaw rate sensor has trouble, DTCs for the steering angle sensor may be
output even when the steering angle sensor is normal. When DTCs for the speed sensor or yaw rate
sensor are output together with other DTCs for the steering angle sensor, inspect and repair the speed
sensor and yaw rate sensor first, and then inspect and repair the steering angle sensor.
1.CHECK HARNESS AND CONNECTOR (MOMENTARY INTERRUPTION)
a. Using the hand-held tester, check for any momentary interruption in the wire harness and
connectors between the skid control ECU and steering angle sensor (see CHECK FOR
INTERMITTENT PROBLEMS ).
MEASUREMENT ITEM / RANGE (DISPLAY) DESCRIPTION
OK: Go to next step
There are no momentary interruptions.
NG: REPAIR OR REPLACE HARNESS OR CONNECTOR (SKID CONTROL ECU -
STEERING ANGLE SENSOR)
OK: Go to next step
2.READ VALUE OF HAND-HELD TESTER (STEERING ANGLE SENSOR VALUE)
a. Connect the hand-held tester to the DLC3.
b. Start the engine.
c. Select the DATA LIST mode on the hand-held tester.
Fig. 77: DATA LIST Mode Description

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d. Check that the steering angle sensor value of the steering angle sensor observed in the hand-held
tester changes when the steering wheel is moved.
OK: Go to next step
Steering angle value changes.
ItemMeasurement Item / Range (Display)Normal Condition
STEERING SENSteering sensor open detectionOPEN: Momentary interruption

Fig. 81: Identifying Yaw Rate And Deceleration Sensor Connector Terminals (1 Of 2)
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TESTER CONNECTION SPECIFIED CONDITION
NG: REPAIR OR REPLACE HARNESS OR CONNECTOR
OK: Go to next step
3.CHECK HARNESS AND CONNECTOR (GND TERMINAL)
a. Disconnect the yaw rate and deceleration sensor connector.
b. Measure the resistance according to the value (s) in the table below.
Standard:
Tester ConnectionSpecified Condition
Y1-5 (IG) - Body ground10 to 14V

TESTER CONNECTION SPECIFIED CONDITION
NG: REPAIR OR REPLACE HARNESS OR CONNECTOR
Fig. 82: Identifying Yaw Rate And Deceleration Sensor Connector Terminals (2 Of 2)

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OK: REPLACE ABS & TRACTION ACTUATOR ASSY (SEE REPLACEMENT
)
Tester ConnectionSpecified Condition
Y1-1 (GND) - Body groundBelow 1 ohms

CONDITION DESCRIPTION
B: REPAIR OR REPLACE HARNESS OR CONNECTOR
Fig. 86: Oscilloscope Waveform Signal Description

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A: Go to next step
3.RECONFIRM DTC
a. Clear the DTC.
b. Turn the ignition switch to the ON position.
c. Check that the same DTC is recorded (see DTC CHECK/CLEAR
).
OK: Go to next step
The same DTC is recorded.
NG: REPLACE ABS & TRACTION ACTUATOR ASSY
OKNo ChangeA
NGChangeB

TESTER CONNECTION SPECIFIED CONDITION
NG: REPAIR OR REPLACE HARNESS OR CONNECTOR (GND TERMINAL - BODY
GROUND)
Fig. 92: Identifying Skid Control ECU Connector Terminals

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OK: CHECK AND REPAIR HARNESS AND CONNECTOR (IG1 TERMINAL - BATTERY)
CIRCUIT DESCRIPTION
Master c
ylinder pressure sensor is connected to the skid control ECU in the actuator.
Tester ConnectionSpecified Condition
S42-32 (GND) - Body groundBelow 1ohms

Fig. 98: Pedal Condition Reference Table
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NG: Go to step 6
HINT:
Check the stop lamp bulb as it may have burnt out.
OK:
2.INSPECT MULTIPLEX COMMUNICATION SYSTEM (SEE HOW TO PROCEED WITH
TROUBLESHOOTING )
a. Is DTC output Multiplex communication system?
Result:
DTC OUTPUT DESCRIPTION
B: REPAIR MULTIPLEX COMMUNICATION SYSTEM
A: Go to next step
3.CHECK HARNESS AND CONNECTOR (STP1 TERMINAL VOLTAGE OF DRIVER SIDE J/B
ECU)
a. Disconnect the driver side J/B ECU connector.
b. Measure the voltage according to the value (s) in the table below.
Standard:
TESTER CONNECTION SPECIFIED CONDITION
DTC is not outputA
TDC is outputB
Tester ConnectionSwitch ConditionSpecified Condition
D3-13 (STP1) - Body ground Brakepedal depressed8 to 14 V
D3-13 (STP1) - Body groundBrake pedal releasedBelow 1 V

Fig. 102: Identifying Stop Lamp Switch Connector And Driver Side J/B Connector Terminals
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NG: REPAIR OR REPLACE HARNESS OR CONNECTOR
OK: Go to next step
8.CHECK HARNESS AND CONNECTOR (STPA OF DRIVER SIDE J/B ECU - STP OF SKID
CONTROL ECU)
a. Disconnect the driver side J/B connector and skid control ECU connector.
b. Measure the resistance according to the value (s) in the table below.
Standard:
TESTER CONNECTION SPECIFIED CONDITION
Standard:
TESTER CONNECTION SPECIFIED CONDITION
Tester ConnectionSpecified Condition
D5-3 (STPA) - S42-27 (STP)Below 1 ohms
Tester ConnectionSpecified Condition
S42-27 (STP) - Body ground1 Mohms or higher

VEHICLE CONDITION / TEST DETAILS
OK: Go to next step
The operation sound of the ABS motor is heard.
OK: Go to step 2
NG: REPLACE ABS & TRACTION ACTUATOR ASSY (SEE REPLACEMENT
)
2.INSPECT HARNESS AND CONNECTOR (GND2 OF SKID CONTROL ECU AND BODY
GROUND)
a. Disconnect the skid control ECU connector.
b. Measure the resistance according to the value (s) in the table below.
Standard:
TESTER CONNECTION SPECIFIED CONDITION
NG: REPAIR OR REPLACE HARNESS OR CONNECTOR
ItemVehicle Condition / Test DetailsVehicle Condition / Test Details
Turns ABS MOT RELAYABS motor relay / ON or OFFON: Motor relay ON
Tester ConnectionSpecified Condition
S42-1 (GND2) - Body groundBelow 1 ohms