NHTSA ID Number: 10203537
Manufacturer Communication Number: L-SB-0035-21
TSB/Document Date: 2021-11-15
Summary
TSB: Some 2016 ? 2021 model year RX 450h vehicles may exhibit a squawk/knock noise from the engine compartment when depressing and/or releasing the brake pedal. This may be due to small amounts of air within the brake actuator assembly. Follow the Repair Procedure in this bulletin to address this condition.
L-SB-0035-21
October 4, 2021
Brake Squawk/Knock Noise
Service
Category
Brake
Section
Brake Control/Dynamic Control System
Market USA
Applicability
YEAR(S)
MODEL(S)
2016 - 2021
RX450H
ADDITIONAL INFORMATION
SUPERSESSION NOTICE
The information contained in this bulletin supersedes Service Bulletins L-SB-0004-19 and
L-SB-0005-21.
Service Bulletins L-SB-0004-19 and L-SB-0005-21 are obsolete, and any printed versions should
be discarded.
Introduction
Some 2016 – 2021 model year RX 450h vehicles may exhibit a squawk/knock noise from the
engine compartment when depressing and/or releasing the brake pedal. This may be due to small
amounts of air within the brake actuator assembly. Follow the Repair Procedure in this bulletin to
address this condition.
Warranty Information
OP CODE
Model Year
DESCRIPTION
TIME
BR1919
2016 – 2021
Brake Actuator Replacement &
Brake Bleed
3.8
Combo A
2016 – 2017
Reprogram ECU
0.3
Combo B
2016 – 2018
R & R Master Cylinder Reservoir
1.2
OFP
T1
T2
44050-48320
91
99
APPLICABLE WARRANTY
This repair is covered under the Lexus
Basic Warranty. This warranty is in effect for 48 months
or 50,000 miles, whichever occurs first, from the vehicle’s in-service date.
Warranty application is limited to occurrence of the specified condition described in
this bulletin.
© 2021 Lexus, a division of Toyota Motor Sales, USA
Page 1 of 19
L-SB-0035-21
October 4, 2021
Page 2 of 19
Brake Squawk/Knock Noise
Parts Information
PART NUMBER
PART NAME
QTY
Reservoir Assembly, Master Cylinder
1
44050-48320
Actuator Assy, Brake
1
895B0-48030
895B0-48031
Computer Assy, Skid Control ECU
–
00475-1BF03
5 – 10
00451-00001-LBL
Authorized Modifications Label
1
PREVIOUS
NEW
47220-48270
47220-48271
NOTE
The ECU should NOT be replaced as part of the Repair Procedure.
Authorized Modifications Labels may be ordered in packages of 25 from the Materials
Distribution Center (MDC) through Dealer Daily – Parts – Dealer Support Materials Orders.
Required Tools & Equipment
REQUIRED EQUIPMENT
SUPPLIER
PART NUMBER
Techstream ADVI*
QTY
TSADVUNIT
Techstream 2.0
TS2UNIT
ADE
1
Techstream Lite
TSLITEPDLR01
Techstream Lite (Green Cable)
TSLP2DLR01
*Essential SST.
NOTE
Only ONE of the Techstream units listed above is required.
Software version 16.20.027 or later is required.
Additional Techstream units may be ordered by calling Approved Dealer Equipment (ADE)
at 1-800-368-6787.
Use Techstream or an approved J2534 interface to perform flash reprogramming updates.
Visit techinfo.toyota.com for more information regarding J2534 reprogramming.
SPECIAL SERVICE TOOLS (SST)
PART NUMBER
QTY
Battery Diagnostic Tool*
DCA-8000P T
1
*Essential SST.
NOTE
Additional SSTs may be ordered by calling 1-800-933-8335.
© 2021 Lexus, a division of Toyota Motor Sales, USA
L-SB-0035-21
October 4, 2021
Page 3 of 19
Brake Squawk/Knock Noise
Calibration Information
CALIBRATION ID
MODEL
ECU
PREVIOUS
NEW
F152648501
Main
F152648740
F152648502
RX 450h
F152648511
Sub
F152648750
F152648512
Repair Procedure
1. Confirm the condition exists.
Is there a squawk/knock noise from the engine compartment when depressing and/or
releasing the brake pedal?
YES — Continue to step 2.
NO — This bulletin does NOT apply. Continue diagnosis using the applicable
Repair Manual.
2. Are ANY DTCs stored related to a noise present during brake application?
YES — This bulletin does NOT apply. Continue diagnosis using the applicable
Repair Manual.
NO — Continue to step 3.
3. Replace the brake actuator.
Refer to TIS, applicable model and model year Repair Manual:
2016 RX 450h:
Brake – Brake Control/Dynamic Control System – “Brake Control / Dynamic Control
Systems: Brake Actuator: Removal / Installation”
2017 – 2018 RX 450h:
Brake – Brake Control/Dynamic Control System – “Brake Control / Dynamic Control
Systems: Brake Actuator: Removal / Installation”
2019 RX 450h:
Brake – Brake Control/Dynamic Control System – “Brake Control / Dynamic Control
Systems: Brake Actuator: Removal / Installation”
2020 – 2021 RX 450h:
Brake – Brake Control/Dynamic Control System – “Brake Control / Dynamic Control
Systems: Brake Actuator: Removal / Installation”
© 2021 Lexus, a division of Toyota Motor Sales, USA
L-SB-0035-21
October 4, 2021
Page 4 of 19
Brake Squawk/Knock Noise
Repair Procedure (continued)
4. Is the vehicle a 2016 – 2018 model year RX 450h?
YES — Continue to step 5.
NO — Go to step 10.
5. Replace the master cylinder reservoir assembly.
Refer to TIS, applicable model and model year Repair Manual:
2016 RX 450h:
Brake – Brake Control/Dynamic Control System – “Brake Control / Dynamic Control
Systems: Brake Actuator: Removal / Installation”
2017 – 2018 RX 450h:
Brake – Brake Control/Dynamic Control System – “Brake Control / Dynamic Control
Systems: Brake Actuator: Removal / Installation”
6. Is the vehicle a 2016 – 2017 model year RX 450h?
YES — Continue to step 7.
NO — Go to step 10.
© 2021 Lexus, a division of Toyota Motor Sales, USA
L-SB-0035-21
October 4, 2021
Page 5 of 19
Brake Squawk/Knock Noise
Repair Procedure (continued)
7. Use Techstream to confirm if the skid control ECU calibration has been updated and check
for the Authorized Modifications Label affixed to the vehicle in the location shown below.
Is the calibration ID listed in Techstream and on the label the latest skid control
ECU calibration?
YES — Go to step 10.
NO — Continue to step 8.
Figure 1. Location of Authorized Modifications Label on 2016 – 2017 RX 450h
TOYOTA MOTOR CORPORATION
AUTHORIZED MODIFICATIONS
THE FOLLOWING MODIFICATIONS HAVE BEEN MADE:
1
2
THESE MODIFICATIONS HAVE BEEN APPROVED
AS APPROPRIATE BY EPA AND CARB
3
DEALER CODE:
CHANGE AUTHORITY:
4
DATE:
5
1
Replacement Skid Control Part Number
(e.g., 895B0-48030 or 895B0-48031)
4
Date Completed
2
New Calibration ID (e.g., F152648740)
5
This SB Number
3
Dealer Code
© 2021 Lexus, a division of Toyota Motor Sales, USA
L-SB-0035-21
October 4, 2021
Page 6 of 19
Brake Squawk/Knock Noise
Repair Procedure (continued)
8. Flash reprogram the skid control ECU.
NOTE
The battery diagnostic tool MUST be used in Power Supply Mode to maintain battery voltage at
13.5V while flash reprogramming the vehicle.
For details on how to use the battery diagnostic station, refer to the DCA-8000 Instruction Manual
located at TIS – Diagnostics – Tools & Equipment – Battery Diagnostics.
Follow the procedures outlined in L-SB-0001-18, Techstream ECU Flash Reprogramming
Procedure, and flash the skid control ECU with the NEW calibration file update.
9. Prepare and install the Authorized Modifications Label.
A. Using a permanent marker, enter the following information on the label:
Skid control ECU part number [Refer to the Parts Information section for the NEW
PART NUMBER]
Calibration ID(s) [Refer to the Calibration Information section for the
NEW CALIBRATION ID]
Dealer Code
Repair Date
Change Authority [This bulletin number]
B. Install the Authorized Modifications Label onto the vehicle at the location shown in
Figure 1. The Authorized Modifications Label is available through the MDC,
P/N 00451-00001-LBL.
© 2021 Lexus, a division of Toyota Motor Sales, USA
L-SB-0035-21
October 4, 2021
Page 7 of 19
Brake Squawk/Knock Noise
Repair Procedure (continued)
10. Using Techstream, perform the following modified air bleeding procedure.
CAUTION
The Techstream MUST be used for air bleeding. If the Techstream is NOT used, the bleeding
procedure will be incomplete, which is hazardous and may lead to an accident.
NOTICE
Adjust the brake fluid level so that the brake fluid level is at the MAX line with the
ignition ON.
Perform air bleeding with the shift lever in (P) Park and the parking brake applied.
As brake fluid may overflow when bleeding, do NOT place the brake fluid can on the brake
master cylinder reservoir assembly filler opening.
Perform air bleeding while maintaining the brake fluid level between the MAX and MIN
lines on the brake master cylinder reservoir assembly.
Air bleeding will be difficult if the following occurs:
The No. 2 brake actuator hose (the hose between the brake booster pump assembly and
brake master cylinder reservoir assembly) is higher than the brake fluid level and air
enters the No. 2 brake actuator hose.
During the bleeding procedure, air enters the brake booster pump assembly while it
is operating.
With the auxiliary battery connected, the brake control system operates when a door
courtesy switch or brake pedal is operated even with the power switch off. Therefore, if
performing any work where it is possible for air to become trapped inside the brake
actuator hose, disconnect the two brake booster pump connectors before work.
While performing air bleeding, the accumulator pressure drop may cause a buzzer to
sound. As there is no problem, continue with air bleeding.
During air bleeding, DTCs for pressure sensor malfunctions, etc., may be stored. AFTER
air bleeding and if instructed in the procedures, clear the DTCs.
Do NOT allow brake fluid on any painted vehicle body surface. If brake fluid leaks onto any
painted surface, immediately wash it off.
© 2021 Lexus, a division of Toyota Motor Sales, USA
L-SB-0035-21
October 4, 2021
Page 8 of 19
Brake Squawk/Knock Noise
Repair Procedure (continued)
A. Turn the ignition ON.
B. Shift to the (P) Park position.
C. Turn the parking brake ON.
D. Turn the ignition OFF.
E. Connect Techstream to the DLC3 and turn the ignition ON.
F. From the Techstream screen, select Chassis.
G. Select ABS-VSC-TRC.
H. Select Reset Memory.
I.
Select Delete the Back-Up Memory.
CAUTION
Once “Delete the Back-Up Memory” is complete, the zero-point memory for the yawrate sensor and G sensor will also be deleted. Make sure to perform a zero-point
acquisition for the yaw-rate sensor and G sensor.
After the zero-point memory for the yaw-rate sensor and G sensor have been deleted,
and if 15 seconds pass while the shift position is at “P” and the ignition is ON, only
the yaw-rate sensor zero-point will be stored. If a vehicle is operated under this
condition, Non-Corrected G Sensor zero-point Malfunction will be stored, and its DTC
will be output. Ensure the ignition is turned OFF AFTER the zero-point memory for the
yaw-rate sensor and G sensor have been deleted to prevent this from occurring.
J. While the ignition is OFF, disconnect the
two brake booster pump connectors.
Figure 2.
1
c
1
c
1
Brake Booster Pump Connectors
- Mixes well with conventional fluids
- Low-moisture formula provides excellent vapor lock...
- Ideal for hydraulic and disc brakes
- Provides an extra margin of safety in extreme braking...
- Mix of polyglycol ethers ensures hot brake-system operation...
- Excellent for ABS, disc and drum brake systems
- Delivers braking power when needed by avoiding a spongy...
- Both wet and dry boiling points exceed the minimum...
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TSB/Document ID: L-SB-0035-21
Replacement Service Bulletin Number:
MFR Communication Date: 2021-10-04
MFR Internal Campaign ID/Software Version:
Communication Type: Service Bulletin/Repair Instructions
NHTSA Components: ENGINE AND ENGINE COOLING
MFR Component System:
MFR Component Subsystem:
Previous TSB | Next TSB |
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