brake fluid LEXUS LS430 2003 Factory Repair Manual

If a collision (front collision) is determined to be unavoidable, the pre-collision brake assist system
receives the brake assist standby signal from the distance control ECU and enters brake assist standby
mode.
If the STP signal is input, the pre-collision brake assist system improves deceleration performance by
increasing pressure according to the amount of brake pedal effort.
The hand-held tester can be used at step 5, 8, 11, 14
1.Vehicle Brought to Workshop
2.(SEE CUSTOMER PROBLEM ANALYSIS CHECK
)
3.Check MULTIPLEX COMMUNICATION SYSTEM (SEE HOW TO PROCEED WITH
TROUBLESHOOTING )
DTC is output: Check MULTIPLEX COMMUNICATION circuit (SEE HOW TO PROCEED
WITH TROUBLESHOOTING )
There is no output: Go to step 4
4.(SEE CHECK CAN BUS LINE
)
DTC is output: Check CAN COMMUNICATION circuit (SEE SKID CONTROL ECU
COMMUNICATION STOP MODE )
There is no output: Go to step 5
5.Check and Clear DTCs (SEE DTC CHECK/CLEAR
)
6.Problem Symptom Confirmation
Symptom does not occur: Go to step 7
Symptom occurs: Go to step 8
7.Symptom Simulation (SEE ELECTRONIC CIRCUIT INSPECTION PROCEDURE
)
8.(SEE DTC CHECK/CLEAR
)
There is no output: Go to step 9
There is output: Go to step 10
9.(SEE PROBLEM SYMPTOMS TABLE
)
Check for fluid leakage and Go to step 10

SKID CONTROL ECU
Fig. 29: Installing SKID Control ECU Connector Terminals

Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
HINT:
Inspect the ECU from the wire harness side while the connector is connected.
TERMINALS NUMBER AND SPECIFIED CONDITION
Symbols
(Terminals No.)Wiring
ColorTerminal DescriptionConditionSpecified
Condition
BM (S42-2) - GND
(S42-1, 32)R - BR,
W-BMotor relay test inputIG switch ON, pump
motor running11 to 14 V
FR+ (S42-3) - FR-
(S42-17)LG -LFront RH wheel speed
signal inputIG switch ON, slowly turn
right front wheelAC generation
RR+ (S42-5) - RR-
(S42-19)R - GRear RH wheel speed signal
inputIG switch ON, slowly turn
right rear wheelAC generation
FSW+ (S42-7) -
GND (S42-1, 32)GR - BR,
W-BFSW switch inputIG switch ON, brake
pedal released2 to 4 V
LBL (S42-10) -
GND (S42-1, 32)G-O - BR,
W-BBrake fluid level warning
switch InputIG switch ON, Brake fluid
level warning switch OFF11 to 14 V
LBL (S42-10) -
GND (S42-1, 32)G-O - BR,
W-BBrake fluid level warning
switch InputIG switch ON, Brake fluid
level warning switch ONBelow 1.5 V
CANH (S42-11) -
CANL (S42-25)BR- YCAN communication lineIG switch OFF54 to 67 ohms
SP1 (S42-12) -GND
(S42-1, 32)R-Y - BR,
W-BSpeed signal outputVehicle drives at approx.
12 mph (20 km/h)Pulse generation
D/G (S42-13) -
GND (S42-1, 32)W-G - BR,
W-BDiagnosis tester
communication lineIG switch ON11 to 14 V
MRF (S42-14) - R+
(S42-45)G-B - R-
WFail safe motor relay outputIG switch ON11 to 14 V
MR (S42-15) - R+
(S42-45)L-R - R-WMotor relay outputIG switch ON, pump
motor running11 to 14 V

c. Select the DATA LIST mode on the hand-held tester.
MEASUREMENT ITEM / RANGE (DISPLAY) DESCRIPTION
d. Check that the brake fluid pressure value of the master cylinder pressure sensor observed in the
hand held tester changes when the brake pedal is depressed.
OK: Go to next step
When the pedal is depressed, displayed voltage on the hand-held tester increases.
NG: Go to step 2
OK: REPLACE ABS & TRACTION ACTUATOR ASSY (SEE REPLACEMENT
)
2.INSPECT SKID CONTROL ECU TERMINAL VOLTAGE (STP TERMINAL)
a. Disconnect the skid control ECU connector.
b. Measure the voltage according to the value (s) in the table below.
Standard:
TESTER CONNECTION SPECIFIED CONDITION
NG: CHECK AND REPLACE STOP LIGHT SWITCH CIRCUIT
OK: REPLACE ABS & TRACTION ACTUATOR ASSY (SEE REPLACEMENT
)
ItemMeasurement Item / Range (Display)Normal Condition
MAS CYL PRS
1Master cylinder pressure sensor 1 reading /
min.: 0 V, max.: 5 VWhen brake pedal is released:
0.3 to 0.9V
Tester ConnectionSwitch ConditionSpecified Condition
S42-27 (STP) - Body groundBrake pedal depressed8 to 14V
S42-27 (STP) - Body groundBrake pedal releasedBelow 1 V

CIRCUIT DESCRIPTION
The BRAKE warning light comes on when the brake fluid is insufficient, the parking brake is applied or the
EBD is defective.
The skid control ECU is connected to the combination meter via CAN and Multiplex communications.
The pad wear indicator is installed to the brake pad (right side).
If the wear indicator wire is open, "Brake Wear" appears on the multi-information display, which indicates that
the pad must be replaced.
WIRING DIAGRAM

INSPECTION PROCEDURE
HINT:
When releasing the parking brake, set the chocks to hold the vehicle for safety.
Check that "Brake Wear" does not appear on the multi-information display.
If it appears, check that brake pad thickness and replace the pad as necessary.
1.CHECK BRAKE FLUID LEVEL IN RESERVOIR
a. Check that the brake fluid level is proper.
OK: Go to next step
Brake fluid level is proper.
NG: ADD BRAKE FLUID
OK: Go to next step
2.CHECK DTC
a. Are the DTC recorded for ABS, VSC, CAN and/or Multiplex communication system?
OK: Go to next step
DTC OUTPUT DESCRIPTION
B: REPAIR CIRCUIT INDICATED BY OUTPUT CODE
A: Go to next step
3.INSPECT BRAKE WARNING LIGHT
a. Connect the hand-held tester to the DLC3.
b. Start the engine.
c. Select the item "BRAKE WARN LIGHT" in the ACTIVE TEST and operate the BRAKE warning
light on the hand-held tester.
VEHICLE CONDITION / TEST DETAILS
d. Check that "ON" and "OFF" of the BRAKE warning light are indicated on the combination meter
when usin
g the hand-held tester.
DTC is not outputA
DTC is outputB
ItemVehicle Condition / Test DetailsDiagnostic Note
BRAKE WRN LIGHTTurns BRAKE warning light ON / OFFObserve combination meter

NG: REPAIR OR REPLACE HARNESS OR CONNECTOR
Fig. 123: Identifying Skid Control ECU Terminals

Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
OK: Go to next step
6.INSPECT BRAKE FLUID LEVEL WARNING SWITCH
a. Remove the reservoir tank cap and strainer.
S42-28 (PKB) - Body ground1M ohms or higher

b. Disconnect the brake fluid level warning switch connector.
c. Measure the resistance according to the value (s) in the table below.
Standard:
TESTER CONNECTION SPECIFIED CONDITION
NG: REPLACE BRAKE FLUID LEVEL WARNING SWITCH
Fig. 124: Identifying Brake Fluid Level Warning Switch Terminals

Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
OK: Go to next step
7.CHECK HARNESS OR CONNECTOR (BRAKE FLUID LEVEL WARNING SWITCH SKID
CONTROL ECU)
Tester ConnectionSwitch ConditionSpecified Condition
(B1-1) - (B1-2)Float UP1M ohms or higher
(B1-1) - (B1-2)Float DOWNBelow 1 ohms

a. Disconnect the skid control ECU connector and the brake fluid level warning switch connector.
b. Measure the resistance according to the value (s) in the table below.
Standard:
TESTER CONNECTION SPECIFIED CONDITION
c. Measure the resistance according to the value (s) in the table below.
Standard:
TESTER CONNECTION SPECIFIED CONDITION
NG: REPAIR OR REPLACE HARNESS OR CONNECTOR
Tester ConnectionSpecified Condition
S42-10 (LBL) - (B1-1)Below 1 ohms
Tester ConnectionSpecified Condition
S42-10 (LBL) - Body ground1 Mohms or higher

PRECAUTION
1. The automatic transmission is composed of highly precision-finished parts which need careful inspection
before reassembly because even a small nick could cause fluid leakage or affect performance. The
instructions here are organized so that you work on only one component group at a time. This will help
avoid confusion from similar-looking parts of different sub-assemblies being on your workbench at the
same time. The component groups should be inspected and repaired from the converter housing side.
Inspect, repair and reassemble as much as possible before proceeding to the next component group. If a
defect is found in a certain component group during reassembly, inspect and repair this group
immediately. If a component group cannot be assembled because parts are being ordered, be sure to keep
all parts of the group in a separate container while proceeding with disassembly, inspection, repair and
reassembly of other component groups. Recommended ATF: ATF WS
2. All disassembled parts should be washed clean and any fluid passages and holes should be blown through
with compressed air.
3. Dry all parts with compressed air. Never use shop rags.
4. When using compressed air, be careful not to not aim at yourself to prevent accidentally spraying ATF or
kerosene on your face.
5. Only recommended automatic transaxle fluid or kerosene should be used for cleaning.
6. After cleaning, the parts should be arranged in the correct order for efficient inspection, repairs, and
reassembly.
7. When disassembling a valve body, be sure to match each valve together with the corresponding spring.
8. New discs for the brakes and clutches that are to be used for replacement must be soaked in ATF for at
least 15 minutes before reassembly.
9. All oil seal rings, clutch discs, clutch plates, rotating parts, and sliding surfaces should be coated with
ATF prior to reassembly.
10. All gaskets and rubber O-rings should be replaced.
11. Do not apply adhesive cements to gaskets or similar parts.
12. Make sure that the ends of a snap ring are not aligned with one of the cutouts and are installed in the
groove correctly.
13. When replacing a worn bushing, the sub-assembly containing the bushing must also be replaced.
14. Check thrust bearings and races for wear or damage. Replace them as necessary.
15. Use petroleum jelly to keep parts in place.
16. When working with FIPG material, perform the following: Using a razor blade and a gasket scraper,
remove all the old packing (FIPG) material from the gasket surface.
Thoroughly clean all components to remove any loose material.

Fig. 98: Staking Nut
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
24.INSTALL PROPELLER W/CENTER BEARING SHAFT ASSY (SEE OVERHAUL
)
25.FULLY TIGHTEN CENTER SUPPORT BEARING ASSY NO.1 (SEE OVERHAUL
)
26.INSTALL EXHAUST PIPE ASSY (SEE REPLACEMENT
)
27.ADD AUTOMATIC TRANSMISSION FLUID (SEE ADJUSTMENT
)
Fluid type: ATF WS
Capacity: 1.7 liters (1.8 US qts, 1.5 Imp.qts)
ON-VEHICLE INSPECTION
1.CHECK SHIFT LOCK OPERATION
a. Move the shift lever to the P position.
b. Turn the ignition switch to the LOCK position.
c. Check that the shift lever cannot be moved to any position other than P.
d. Turn the ignition switch to the ON position, depress the brake pedal and check that the shift lever
can be moved to another position.