ignition LEXUS LS430 2003 Factory Owner's Manual

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

NG: Go to step 3
OK: REPLACE ABS & TRACTION ACTUATOR ASSY (SEE REPLACEMENT
)
3.CHECK TERMINAL VOLTAGE (STEERING ANGLE SENSOR CONNECTOR)
a. Remove the steering wheel and the column lower cover.
b. Disconnect the steering angle sensor connector.
c. Turn the ignition switch to the ON position.
d. Measure the voltage according to the value (s) in the table below.
Standard:
TESTER CONNECTION SPECIFIED CONDITION
e. Measure the voltage according to the value (s) in the table below.
Standard:
TESTER CONNECTION SPECIFIED CONDITION
Tester ConnectionSpecified Condition
S16-1 (IG1) - S16-2 (ESS)10 to 14V
Tester ConnectionSpecified Condition
S16-3 (BAT) -S16-2 (ESS)10 to 14V

When U0123/62, U0124/95 or U0126/63 are output together with C1232/32, C1234/34, C1243/43, C1244/44,
C1245/45, and C1381/97 inspect and repair the trouble areas indicated by U0121/94, U0123/62, U0124/95 or
U0126/63 first.
1.CHECK SENSOR INSTALLATION (YAW RATE SENSOR)
a. Check that the yaw rate and deceleration sensor has been installed properly (see
REPLACEMENT
).
OK: Go to next step
The sensor is tightened to the specified torque.
The sensor is not tilted.
NG: INSTALL YAW RATE SENSOR CORRECTLY
OK: Go to next step
2.CHECK HARNESS AND CONNECTOR (IG TERMINAL)
a. Disconnect the yaw rate and deceleration sensor connector.
b. Turn the ignition switch to the ON position.
c. Measure the voltage according to the value (s) in the table below.
Standard:

Fig. 85: Normal Signal Waveform
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
NG: Go to step 4
OK: Go to next step
2.INSPECT SPEED SENSOR AND SENSOR ROTOR SERRATIONS
INSPECTION USING OSCILLOSCOPE
a. Connect the oscilloscope to terminal FR+ - FR- or FL+ - FL- of the skid control ECU.
b. Check if the oscilloscope has any change when the wire harness connector is subject to vibration
while the vehicle is stopped and the ignition switch is on.
(If the connector is poorly connected, vibration of the wire harness connector may cause a temporary stop
in current flow.)
OK: Go to next step
There is no change in a waveform

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

Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
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

OK: Go to next step
5.RECONFIRM DTC
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:
The same DTC is recorded.
NG: PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS
TABLE
OK: REPLACE ABS & TRACTION ACTUATOR ASSY (SEE REPLACEMENT
)
6.INSPECT STOP LAMP SWITCH ASSY
a. Disconnect the stop lamp switch assy connector.
b. Measure the resistance according to the value (s) in the table below.
Standard:
TESTER CONNECTION SPECIFIED CONDITION
Switch ConditionTester ConnectionSpecified Condition
Switch pin free1 - 2Below 1 ohms
Switch pin pushed in1 - 21 Mohms or higher

OK: Go to next step
9.RECONFIRM DTC
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:
The same DTC is recorded.
NG: PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS
TABLE
OK: REPLACE ABS & TRACTION ACTUATOR ASSY (SEE REPLACEMENT
)
CIRCUIT DESCRIPTION
ABS pump motor is located inside the brake actuator. The motor is used for BA, TRAC and VSC operation.
Fig. 104: DTC C1251/51 Detection Condition And Trouble Area Description Chart

Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
WIRING DIAGRAM

d. Read the value of the brake pedal load sensing switch displayed on the hand-held tester when
depressing and releasing the brake pedal.
Standard:
BRAKE PEDAL STANDARD DESCRIPTION
NG: Go to step 3
OK: Go to next step
2.RECONFIRM DTC
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: Go to step 3
OK: REPAIR CIRCUIT INDICATED BY OUTPUT CODE
3.INSPECT BRAKE PEDAL SUB-ASSY
HINT:
When there is a malfunction in the brake pedal load sensing switch replace the brake pedal sub-assy.
a. Disconnect the brake pedal load sensing switch connector B3.
b. Measure the resistance according to the value (s) in the table below.
Standard:
TESTER CONNECTION SPECIFIED CONDITION
ConditionDisplay
Depress the brake pedalON
Release the brake pedalOFF
Tester ConnectionConditionSpecified Condition
B3-2 (FSW+) - B3-1 (GND)Depress brake pedalApprox. 1000 ohms
B3-2 (FSW+) - B3-1 (GND)Release brake pedalApprox. 213 ohms

Fig. 134: TC And CG Terminal Wiring Diagram
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
INSPECTION PROCEDURE
1.INSPECT DLC3 TERMINAL VOLTAGE (DLC3 TERMINAL VOLTAGE)
a. Turn the ignition switch to the ON position.
b. Measure the voltage according to the value (s) in the table below.
Standard:
TESTER CONNECTION SPECIFIED CONDITION
NG: GO TO STEP 3
Tester ConnectionSpecified Condition
D1-13 (TC) - Body ground10 to 14 V

Result:
DTC OUTPUT DESCRIPTION
B: REPAIR CIRCUIT INDICATED BY OUTPUT CODE (SEE DIAGNOSTIC TROUBLE CODE
CHART )
A: REPLACE ABS & TRACTION ACTUATOR ASSY (SEE REPLACEMENT
)
CIRCUIT DESCRIPTION
In the sensor check mode, a malfunction of the speed sensor that cannot be detected when the vehicle is stopped
is detected while driving.
Transition to the sensor check mode can be performed by connecting terminals TS and CG of the DLC3 and
turning the ignition switch from off to the ON position.
WIRING DIAGRAM
DTC is not outputA
DTC is outputB