LEXUS LS430 2003 Factory Repair Manual

Dynamic
Radar/Laser
Cruise
(Maintains
vehicle-to-
vehicle
distance)
Tx
RxTx Rx Tx Rx
Vehicl
Vehi
dista
n
control
not op
e
Back
Monitor
(Exterior
view from
rear of
vehicle is
displayed
while
reversing)
Tx Rx Back m
onl
Air
Suspension
Control
(Controls
suspension
properly
based on
vehicle
conditions)
TxTx Rx Control
Meter
Display
(Displays
operation
condition
and DTCs)
TxTx RxTx
Lamp
not co
m
or remai
Pre -
collision
Safety (Skid
control ECU
brings BA in
standby
mode and
seat belt is
fastened by
seat belt
control ECU
when
distance
control ECU
determines
that collision
Rx Tx RxPre-col
l
safety sy
does
oper
a

HINT:
Rx: Reception from each ECU (sensor).
Tx: Transmission to each ECU (sensor).
1.DTC TABLE BY ECU
HINT:
If CAN communication system DTCs are output, trouble cannot be determined only by the DTCs.
Perform troubleshooting according to "HOW TO PROCEED WITH TROUBLESHOOTING" (see
HOW TO PROCEED WITH TROUBLESHOOTING
).
a. ECM
HINT:
DTC communication uses the CAN communication system.
Distance control ECU data is also output.
ECM DIAGNOSTIC TROUBLE CODE CHART
*1: The engine control computer is malfunctioning if U0001 is output. Replace the ECM.
*2: Dynamic radar/laser cruise DTC.
b. SKID CONTROL ECU
HINT:
DTC communication uses the SIL line.
SKID CONTROL ECU DIAGNOSTIC TROUBLE CODE CHART
is
unavoidable)
DTC No.Detection Item
U0001High Speed CAN Communication Bus (*1)
U0100Lost Communication With ECM/PCM "A" (*2)
U0122Lost Communication With Vehicle Dynamics Control Module (*2)
U0123Lost Communication With Yaw Rate Sensor Module (*2)
U0126Lost Communication With Steering Angle Sensor Module (*2)
U1101Lost Communication With Distance Control ECU (*2)
DTC No.Detection Item
U0073Control Module Communication Bus Off

c. SUSPENSION CONTROL ECU
HINT:
DTC communication uses the SIL line.
SUSPENSION CONTROL ECU DIAGNOSTIC TROUBLE CODE CHART
d. TELEVISION CAMERA ECU
HINT:
The television camera ECU is connected to the CAN communication system but CAN
communication system DTCs are not output.
e. GATEWAY ECU
HINT:
The gateway ECU is connected to the CAN communication system but CAN communication
system DTCs are not output.
f. SEAT BELT CONTROL ECU
HINT:
DTC communication uses the SIL line.
SEAT BELT CONTROL ECU DIAGNOSTIC TROUBLE CODE CHART
U0100Lost Communication With ECM/PCM "A"
U0123Lost Communication With Yaw Rate Sensor Module
U0124Lost Communication With Lateral Acceleration Sensor Module
U0126Lost Communication With Steering Angle Sensor Module
DTC No.Detection Item
U0100Lost Communication With ECM/PCM "A"
U0101Lost Communication With TCM
U0122Lost Communication With Vehicle Dynamics Control Module
U0124Lost Communication With Lateral Acceleration Sensor Module
U0126Lost Communication With Steering Angle Sensor Module
U0132Lost Communication With Ride Level Control Module
DTC No.Detection Item
U0100Lost Communication With ECM/PCM "A"
U0122Lost Communication With Vehicle Dynamics Control Module

CIRCUIT DESCRIPTION
When any DTC for the CAN communication system is output, first measure the resistance between the
terminals of the DLC3 to specify the trouble area, and check that there is no short in the CAN main bus line,
between the CAN bus lines, to +B, or to GND.
WIRING DIAGRAM
U0145Lost Communication With Body Control Module "E"
U1101Lost Communication With Distance Control ECU

Fig. 31: Wiring Diagram - Can Bus Line (1 Of 2)
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.

Fig. 32: Wiring Diagram - Can Bus Line (2 Of 2)
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
INSPECTION PROCEDURE
1.CHECK CAN BUS LINE (MAIN BUS LINE FOR DISCONNECTION, BUS LINES FOR SHORT
CIRCUIT)

Fig. 33: Identifying DLC3 Connector terminals
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
a. Turn the ignition switch to the LOCK position.
b. Measure the resistance according to the value (s) in the table below.
Standard:
ECM CONNECTOR TERMINALS RESISTANCE
Tester connectionConditionSpecified valueResult
D1-6 (CANH) - D1-14
(CANL)Ignition Switch
OFF54 to 69 ohmsOK
D1-6 (CANH) - D1-14
(CANL)Ignition Switch
OFF69 ohms or more (w/o LEXUS Navigation
system)NG-A
D1-6 (CANH) - D1-14
(CANL)Ignition Switch
OFF69 ohms or more (w/ LEXUS Navigation
System)NG-B
D1-6 (CANH) - D1-14
(CANL)Ignition Switch
OFF54 ohms or less (w/o LEXUS Navigation
System)NG-C

NG-A: CHECK CAN MAIN BUS LINE FOR DISCONNECTION (W/O LEXUS NAVIGATION
SYSTEM)
NG-B: CHECK CAN MAIN BUS LINE FOR DISCONNECTION (W/ LEXUS NAVIGATION
SYSTEM)
NG-C: CHECK CAN BUS LINES FOR SHORT CIRCUIT (W/O LEXUS NAVIGATION
SYSTEM)
NG-D: CHECK CAN BUS LINES FOR SHORT CIRCUIT (W/ LEXUS NAVIGATION SYSTEM)
OK: GO TO NEXT STEP
2.CHECK CAN BUS LINE FOR SHORT TO +B
Fig. 34: Identifying DLC3 Connector terminals

Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
D1-6 (CANH) - D1-14
(CANL)Ignition Switch
OFF54 ohms or less (w/ LEXUS Navigation
System)NG-D

a. Measure the resistance according to the value (s) in the table below.
Standard:
ECM CONNECTOR TERMINALS RESISTANCE
HINT:
NG-A: w/o LEXUS Navigation System.
NG-B: w/ LEXUS Navigation System.
NG-A: CHECK CAN BUS LINE FOR SHORT TO +B (W/O LEXUS NAVIGATION SYSTEM)

NG-B: CHECK CAN BUS LINE FOR SHORT TO +B (W/ LEXUS NAVIGATION SYSTEM)

OK: GO TO NEXT STEP
3.CHECK CAN BUS LINE FOR SHORT TO GND
Tester ConnectionConditionSpecified value
D1-6 (CANH) - D1-16 (BAT)Ignition Switch OFF1 Mohms or more
D1-14 (CANL) - D1-16 (BAT)Ignition Switch OFF1 Mohms or more

Fig. 35: Identifying DLC3 Connector terminals
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
a. Measure the resistance according to the value (s) in the table below.
Standard:
ECM CONNECTOR TERMINALS RESISTANCE
HINT:
NG-A: w/o LEXUS Navigation System.
NG-B: w/ LEXUS Navigation System.
NG-A: CHECK CAN BUS LINE FOR SHORT TO GND (W/O LEXUS NAVIGATION SYSTEM)
Tester ConnectionConditionSpecified value
D1-4 (CG) - D1-6 (CANH)Ignition Switch OFF1 kohms or more
D1-4 (CG) - D1-14 (CANL)Ignition Switch OFF1 kohms or more