2003 LEXUS LS430 Control actuator

Fig. 67: Identifying Absorber Control Actuator Rear LH 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 exhaust solenoid discharges high pressure air from the system by opening the solenoid valve according to
the si
gnal from the suspension control ECU.

Fig. 113: Identifying Suspension Control ECU Connector Terminals
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
NG: CHECK POWER SOURCE CIRCUIT (SEE DTC C1774 POWER SOURCE CIRCUIT
)
OK: REPLACE SUSPENSION CONTROL ECU (SEE REPLACEMENT
)
CIRCUIT DESCRIPTION
When the ignition switch is turned to the ON position, the D-IG1 relay is activated and battery voltage is
applied to terminal B of the suspension control ECU. When the ignition switch is turned off, the D-IG1 relay is
de-energized and the power source is cut off.
This power source energizes the suspension control actuator, height control solenoid valve, D-IG1 relay, each
IC and sensor.

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.

Fig. 8: Wiring Diagram - Can Communication System (W/O LEXUS Navigation System)
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
HINT:
The position of the terminus circuit differs in vehicles with and without the LEXUS navigation system.
The skid control ECU with actuator detects and stores steering sensor and yaw rate sensor DTCs and
performs DTC communication by receiving information from the steering sensor and yaw rate sensor.
The ECM detects and stores distance control ECU DTCs, and performs DTC communication by
receiving information from the distance control ECU.
The ECM uses the CAN communication system to perform DTC communication instead of the

conventional communication line (SIL).
1.BRIEF DESCRIPTION
a. The CAN (Controller Area Network) is a serial data communication system for real time
application. It is a multiplex communication system equipped for a vehicle and has a high
communication speed (500 kbps) and the function to detect malfunctions.
b. By pairing the CANH and CANL bus lines, the CAN performs communication based on
differential voltage.
c. Many ECUs (sensors) installed on the vehicle operate by sharing information and communicating
with each other.
d. The CAN has two resistors of 120 ohms which are necessary to communicate with the main bus
line.
2.DEFINITION OF TERMS
a. Main bus line
1. The main bus line is the wire harness between the two terminus circuits on the bus
(communication line). This is the main bus in the CAN communication system.
b. Sub bus line
1. The sub bus line is the wire harness which diverges from the main bus line to the ECU or
sensor.
c. Terminus circuit
1. The terminus circuit is a circuit which is placed to convert communication current of the
CAN communication into bus voltage. It consists of a resistor and condenser. Two terminus
circuits are necessary on a bus.
d. CAN J/C
1. The CAN J/C is a junction designed for CAN communication, which stores a terminus
circuit.
3.ECUs OR SENSORS WHICH COMMUNICATE THROUGH CAN COMMUNICATION
SYSTEM
a. Skid Control ECU with Actuator
b. Yaw Rate Sensor
c. Steering Sensor
d. Television Camera ECU
e. Seat Belt Control ECU
f. Distance Control ECU
g. Suspension Control ECU
h. ECM
i. Gateway ECU
4.DIAGNOSTIC CODE FOR CAN COMMUNICATION SYSTEM
a. DTCs for the CAN communication system are as follows:

Fig. 39: Identifying Skid Control ECU Connectors
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
a. Measure the resistance according to the value (s) in the table below.
b. Measure the voltage according to the value (s) in the table below.
Standard:
SKID CONTROL ECU CONNECTOR TERMINALS VOLTAGE
NG: REPAIR OR REPLACE WIRE HARNESS OR CONNECTOR
OK: REPLACE SKID CONTROL ECU WITH ACTUATOR (SEE REPLACEMENT
)
Tester ConnectionConditionSpecified value
S42-1 (GND2) - Body groundAlwaysBelow 1
S42-32 (GND1) - Body groundAlwaysBelow 1
S42-46 (IG1) - Body groundIgnition Switch ON10 to 14 V

10.CONNECT CONNECTOR
a. Reconnect the ECM sub bus line connector (J40) to the D-CAN J/C B side (w/o earth terminal).
11.CHECK CAN BUS LINES FOR SHORT CIRCUIT (SKID CONTROL ECU WITH ACTUATOR
SUB BUS LINE)
Fig. 96: Disconnecting Skid Control ECU Sub Bus Line Connector (J41) From D
-CAN J/C (W/O
Earth Terminal)
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
a. Disconnect the skid control ECU sub bus line connector (J41) from the D-CAN J/C (w/o earth
terminal).

Fig. 105: Identifying DLC3 Connector terminals
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
a. Disconnect the skid control ECU connector (S42).
b. Measure the resistance according to the value (s) in the table below.
Standard:
DLC3 CONNECTOR TERMINALS RESISTANCE
OK: REPLACE SKID CONTROL ECU WITH (SEE REPLACEMENT
) ACTUATOR
NG: REPAIR OR REPLACE SKID CONTROL ECU SUB BUS LINE OR CONNECTOR (CAN-
H, CAN-L)
24.CONNECT CONNECTOR
Tester connectionConditionSpecified value
D1-6 (CANH) -D1-14 (CANL)Ignition Switch OFF54 to 69 ohms