2003 LEXUS LS430 bypass

When there is a malfunction in the contact point of the terminals or installation problems with parts,
removal and installation of the suspected problem parts may return the system to the normal condition
either completely or temporarily.
In order to determine the malfunctioning area, be sure to check the conditions at the time the malfunction
occurred, such as by DTC output and the freeze frame data output, and record it before disconnecting
each connector or removing and installing parts.
Since the ABS with EBD & BA & TRAC & VSC systems may be influenced by a malfunction in the
other systems, be sure to check for DTCs in the other systems.
Be sure to remove and install the skid control ECU, ABS & TRAC actuator and each sensor with the IG
switch OFF unless specified in the inspection procedure.
When removing and installing the skid control ECU, ABS & TRAC actuator and each sensor, be sure to
check that the normal display is output in test mode inspection and in DTC output inspection after
installing all the parts.
After replacing the yaw rate sensor and/or the brake actuator assembly, make sure to perform yaw rate
sensor and deceleration sensor zero point calibration.
(see CALIBRATION
)
CAN communication system is used for the data communication between the skid control ECU (included
in the actuator), the steering angle sensor, and the yaw rate sensor (the deceleration sensor is included). If
there is trouble in the CAN communication line, the DTC in the communication line is output.
If the DTC in the CAN communication line is output, repair the malfunction in the communication line
and troubleshoot the ABS with EBD & BA & TRAC & VSC systems under the condition that data
communication is normal.
Since the CAN communication line has its own length and route, it can not be repaired temporarily with
the bypass wire, etc.
SYSTEM NAME REFERENCE
System NameSee Procedure
Front Power Seat Control SystemINITIALIZATION

ROOM TEMP
Room temperature sensor / min.: -
6.5°C (20.3°F) max.: 57.25°C
(126.95°F)
Actual room temperature is displayed-
AMBI TEMP
SENSAmbient temperature sensor /
min.: -23.3°C (-9.94°F) max.:
65.95°C (150.71°F)Actual ambient temperature is
displayed-
EVAP TEMP
Evaporator temperature sensor /
min.: -29.7°C (-21.46°F) max.:
59.55°C (139.19°F)Actual evaporator temperature is
displayed-
SOLAR SENS-DSolar sensor (Driver side) / min.:
0 max.: 255Increases as brightness increases-
SOLAR SENS-PSolar sensor (Passenger side) /
min.: 0 max.: 255decreases as brightness increases-
COOLANT
TEMPEngine coolant temperature /
min.: 1.3°C (34.34°F) max.:
90.55°C (194.99°F)Actual engine coolant temperature is
displayed while the engine is warmed
up
-
DUCT TEMP-D
Duct sensor (Driver side) / min.: -
12.7°C (9.14°F) max.: 76.55°C
(169.79°F)Actual duct temperature is displayed
(Driver side)-
DUST TEMP-P
Duct sensor (Passenger side) /
min.: -12.7°C (9.14°F) max.:
76.55°C (169.79°F)Actual duct temperature is displayed
(Passenger side)-
SET TEMP-DSet temperature (Driver side) /
min.: 0 max.: 255Actual set temperature is displayed
(Driver side)-
SET TEMP-PSet temperature (Passenger
side) /min.: 0 max.: 255Actual set temperature is displayed
(Passenger side)-
ESTIMATE
TEMP-DEstimated temperature (Driver
side) / min.: -358.4°C (-613.12°F)
max.: 358.4°C (677.12°F)Actual estimated temperature is
displayed (Driver side)-
ESTIMATE
TEMP-PEstimated temperature (Passenger
side) / min.: -358.4°C (-613.12°F)
max.: 358.4°C (677.12°F)Actual estimated temperature is
displayed (Passenger side)-
A/I DAMP POSAir inlet damper position / min.: -
14% max.: 113.5%RECIRCULATION: Approx. 0%
FRESH: Approx. 100%-
A/B DAMP POS-
DCool air bypass damper position
(Driver side) / min.: -14% max.:
113.5%OPEN: Approx. 0 % SHUT: Approx.
100%-
A/B DAMP POS-
PCool air bypass damper position
(Passenger side) / min.: -14%
max.: 113.5%OPEN: Approx. 0 % SHUT: Approx.
100%-
ItemMeasurement Item / Display
(Range)Normal ConditionDiagnostic
Note
A/I DAMP
TARGAir inlet damper target / min.: -
14% max.: 113.5%RECIRCULATION: Approx. 0%
FRESH: Approx. 100% HALF-
RECIRCULATION: 43 to 99.5 %
-

side)code 9.
AODr1 - GND
(A37-5 - A11-1)L - W-B
Air outlet servomotor
operation signal (Driver
side)During actuator check mode.
Change display code 0 to display
code 9.Pulse
generation
AODr2 - GND
(A37-6 - A11-1)L-B - W-
BAir outlet servomotor
operation signal (Driver
side)During actuator check mode.
Change display code 0 to display
code 9.Pulse
generation
WVS - GND
(A37-7 - A11-1)G-W - W-
BWater valve servomotor
operation signalIgnition switch ON. Set
temperature control to MAX.
COOL
Below 1.0 V
WVS - GND
(A37-7 - A11-1)G-W - W-
BWater valve servomotor
operation signalIgnition switch ON. Set
temperature control to MAX.
HOT
10 to 14 V
ABOPa - GND
(A37-8 - A11-1)G-B - W-
BCool air bypass
servomotor operation
signal (Passenger side)During actuator check mode.
Display code 0.10 to 14 V
ABOPa - GND
(A37-8 - A11-1)G-B - W-
BCool air bypass
servomotor operation
signal (Passenger side)
Display code 9.Below 1.0 V
Symbols
(Terminal No.)Wiring
colorTerminal DescriptionConditionSpecification
ABSPa - GND
(A37-9 - A11-1)G-O - W-
BCool air bypass
servomotor operation
signal (Passenger side)During actuator check mode.
Display code 0.Below 1.0 V
ABSPa - GND
(A37-9 - A11-1)G-O - W-
BCool air bypass
servomotor operation
signal (Passenger side)
Display code 9.10 to 14 V
AMDB - GND
(A37-10 - A11-1)R-B - W-
BAir mix servomotor
operation voltage (Driver
side)
Always10 to 14 V
AODr3 - GND
(A37-12 - A11-1)L-W - W-
BAir outlet servomotor
operation signal (Driver
side)During actuator check mode.
Change display code 0 to display
code 9.Pulse
generation
AODr4 - GND
(A37-13 - A11-1)L-R - W-
BAir outlet servomotor
operation signal (Driver
side)During actuator check mode.
Change display code 0 to display
code 9.Pulse
generation
WVIG - GND
(A37-14 - A11-1)O - W-BWater valve servomotor
operation voltageIgnition switch ON.10 to 14 V
WVIG - GND
(A37-14 - A11-1)O - W-BWater valve servomotor
operation voltageIgnition switch OFF.0 V
WVO - GND
(A37-15 - A11-1)G - W-BWater valve servomotor
operation signalIgnition switch ON. Set
temperature control to MAX.
COOL.
10 to 14 V
WVO - GND
(A37-15 - A11-1)G - W-BWater valve servomotor
operation signalIgnition switch ON. Set
temperature control to MAX. Below 1.0 V

HOT.
ABODr - GND
(A37-16 - A11-1)GR - W-
BCool air bypass
servomotor operation
signal (Driver side)During actuator check mode.
Display code 0.10 to 14 V
ABODr - GND
(A37-16 - A11-1)GR - W-
BCool air bypass
servomotor operation
signal (Driver side)
Display code 9.Below 1.0 V
ABSDr - GND
(A37-17 - A11-1)GR-R -
W-BCool air bypass
servomotor operation
signal (Driver side)During actuator check mode.
Display code 0.Below 1.0 V
ABSDr - GND
(A37-17 - A11-1)GR-R -
W-BCool air bypass
servomotor operation
signal (Driver side)
Display code 9.10 to 14 V
S5-3 - SG (A37-
18 - A37-19)R-W - W-
BAir inlet damper position
sensor signalIgnition switch ON.4.5 to 5.5 V
TPI - SG (A37-20
- A37-19)B-Y - W-
BAir inlet damper position
sensor signalIgnition switch ON. Push REC
switch.4.0 V
TPI - SG (A37-20
- A37-19)B-Y - W-
BAir inlet damper position
sensor signalIgnition switch ON. Push FRESH
switch.1.0 V
TPBPa - SG
(A37-21 - A37-
19)B-L - W-
BCool air bypass
servomotor operation
signal (Passenger side)Change display code 9 to display
code 0.3.5 to 4.5 V
TPBPa - SG
(A37-21 - A37-
19)B-L - W-
BCool air bypass
servomotor operation
signal (Passenger side)Change display code 2 to display
code 3.0.5 to 1.8 V
AODB - GND
(A37-22 - A11-1)R-Y - W-
BAir outlet servomotor
operation voltage (Driver
side)
Always10 to 14 V
AMPa1 - GND
(A36-1 - A11-1)LG - W-B
Air mix servomotor
operation signal
(Passenger side)During actuator check mode.
Change display code 0 to display
code 9.Pulse
generation
AMPa2 - GND
(A36-2 - A11-1)LG-B -
W-BAir mix servomotor
operation signal
(Passenger side)During actuator check mode.
Change display code 0 to display
code 9.Pulse
generation
AMPa3 - GND
(A36-3 - A11-1)LG-W -
W-BAir mix servomotor
operation signal
(Passenger side)During actuator check mode.
Change display code 0 to display
code 9.Pulse
generation
Symbols
(Terminal No.)Wiring
colorTerminal DescriptionConditionSpecification
AMPa4 - GND
(A36-4 - A11-1)LG-R -
W-BAir mix servomotor
operation signal
(Passenger side)During actuator check mode.
Change display code 0 to display
code 9.Pulse
generation
AOPa1 - GND
(A36-5 - A11-1)P - W-B
Air outlet servomotor
operation signal
(Passenger side)During actuator check mode.
Change display code 0 to display
code 9.Pulse
generation

AOPa2 - GND
(A36-6 - A11-1)P-B - W-
BAir outlet servomotor
operation signal
(Passenger side)During actuator check mode.
Change display code 0 to display
code 9.Pulse
generation
AOPa3 - GND
(A36-7 - A11-1)P-G - W-
BAir outlet servomotor
operation signal
(Passenger side)During actuator check mode.
Change display code 0 to display
code 9.Pulse
generation
AOPa4 - GND
(A36-9 - A11-1)P-L - W-
BAir outlet servomotor
operation signal
(Passenger side)During actuator check mode.
Change display code 0 to display
code 9.Pulse
generation
S5-5 - SG-7(1)
(A36-11 - A36-
15)
R - W-L
Cool air bypass damper
position sensor signal
(Driver side)
Ignition switch ON.4.5 to 5.5 V
S5-5 - SG-7(2)
(A36-11 - A36-
15)
R - W-L
Cool air bypass damper
position sensor signal
(Passenger side)
Ignition switch ON.4.5 to 5.5 V
AMPB - GND
(A36-13 - A11-1)Y - W-B
Air mix servomotor
operation voltage
(Passenger side)
Always10 to 14 V
AIF - SG (A36-
16 - A37-19)G-R - W-
BAir inlet damper position
sensor signalIgnition switch ON. Push REC
switch.Below 1.0 V
AIF - SG (A36-
16 - A37-19)G-R - W-
BAir inlet damper position
sensor signalIgnition switch ON. Push FRESH
switch.10 to 14 V
AIR - SG (A36-
17 - A37-19)G-Y - W-
BAir inlet damper position
sensor signalIgnition switch ON. Push FRESH
switch.Below 1.0 V
AIR - SG (A36-
17 - A37-19)G-Y - W-
BAir inlet damper position
sensor signalIgnition switch ON. Push REC
switch.10 to 14 V
TE - SG-7 (A36-
20 - A36-15)L-Y - W-
LEvaporator temperature
sensor signalIgnition switch ON. Evaporator
temperature 0 °C (32 °F).2.0 to 2.4V
TE - SG-7 (A36-
20 - A36-15)L-Y - W-
LEvaporator temperature
sensor signalIgnition switch ON. Evaporator
temperature 15 °C (59 °F).1.4 to 1.8 V
TPBDr - SG-7
(A36-24 - A36-
15)B-R - W-
LCool air bypass
servomotor operation
signal (Driver side)Change display code 9 to display
code 0.3.5 to 4.5 V
TPBDr - SG-7
(A36-24 - A36-
15)B-R - W-
LCool air bypass
servomotor operation
signal (Driver side)Change display code 2 to display
code 3.0.5 to 1.8 V
AOPB - GND
(A36-26 - A11-1)Y-R - W-
BAir outlet servomotor
operation voltage
(Passenger side)
Always10 to 14 V
(1)w/o LEXUS Navigation System
(2)w/ Rear A/C

Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
NG: REPAIR OR REPLACE HARNESS OR CONNECTOR
OK: REPLACE AIR CONDITIONING AMPLIFIER (SEE REPLACEMENT
)
CIRCUIT DESCRIPTION
This sensor detects the position of the cool air bypass servomotor (Max cool damper servomotor) and sends the
appropriate signals to the A/C amplifier. The position sensor is built in the cool air bypass servomotor.

INSPECTION PROCEDURE
1.READ VALUE ON HAND-HELD TESTER
a. Connect the hand-held tester to the DLC3.
b. Turn the ignition switch to the ON position and push the hand-held tester main switch on.
c. Select the item below in the DATA LIST, and read the display on the hand-held tester.
DATA LIST / AIR CONDITIONER:
DATA LIST / AIR CONDITIONER
OK:
The display is as specified in the normal condition.
Result:
AIR CONDITIONER TEST RESULT
B: PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE
C: REPLACE AIR CONDITIONING AMPLIFIER (SEE REPLACEMENT )
A: Go to next step
2.INSPECT AIR CONDITIONING AMPLIFIER (TPBDr - SG-7)
a. Remove the A/C amplifier with connectors still connected.
b. Turn the ignition switch to the ON position.
c. Change the set temperature to activate the cool air bypass servomotor.
d. Measure the voltage according to the value (s) in the table below.
Standard:
AIR CONDITIONING AMPLIFIER (TPBDr - SG-7) VOLTAGE
ItemMeasure Item/Display (Range)Normal ConditionDiagnostic
Note
A/B DAMP
POS-DCool air bypass damper position (Driver
side) / min.: -14% max.: 113.5%OPEN: Approx. 0 % SHUT:
Approx. 100%-
NGA
OK (Checking from the PROBLEM SYMPTOM TABLE)B
OK (Checking from the DTC)C
Tester connectionConditionSpecified condition
A36-24 (TPBDr) - A36-15 (SG-7)MAX. Hot0.5 to 1.8 V
A36-24 (TPBDr) - A36-15 (SG-7)MAX. Cool3.5 to 4.5 V

HINT:
As the set temperature increases, the voltage decreases gradually without interruption.
Result:
AIR CONDITIONING AMPLIFIER (TPBDR - SG-7) TEST RESULT
Fig. 102: Inspecting Air Conditioning Amplifier (TPBDR
- SG-7)
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
B: PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE
C: REPLACE AIR CONDITIONING AMPLIFIER (SEE REPLACEMENT )
A: Go to next step
3.INSPECT COOL AIR BYPASS SERVOMOTOR
NGA
OK (Checking from the PROBLEM SYMPTOMS TABLE)B
OK (Checking from the DTC)C