NHTSA ID Number: 10245447
Manufacturer Communication Number: L-SB-0032-23 Rev
TSB/Document Date: 2023-11-27
Summary
TSB: Some 2016 ? 2022 model year RX 450h and 2018 ? 2022 model year RX 450hL vehicles may exhibit a squawk/knock noise from the engine compartment when depressing and/or releasing the brake pedal. Follow the Repair Procedure in this bulletin to address this condition.
Make sure that the connector is
locked securely.
Make sure that the actuator
connector can be connected
smoothly. Do NOT allow water,
oil, or dirt to enter the connector.
DO NOT re-connect the brake
booster pump connectors.
2
1
Lock the Lock Lever
2
Connect the Electrical Connector
© 2023 Lexus
, a division of Toyota Motor Sales, USA
L-SB-0032-23
Rev1
May 15, 2023
Page 18 of 30
Brake Squawk/Knock Noise
Repair Procedure (continued)
C. Install the reservoir bracket.
(1) Install the reservoir bracket with the bolt and two nuts.
Torque: 19 N*m (194 kgf*cm, 14 ft*lbf)
(2) Engage the clamp to install the wire harness to the reservoir bracket.
D. Install the No. 1 reservoir hose.
(1) Remove the hose plug and quickly connect the No. 1 reservoir hose to the reservoir
tube and slide the clip to secure it.
11. Using GTS+, perform the following modified air bleeding procedure.
CAUTION
GTS+ MUST be used for air bleeding. If GTS+ 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, wash it OFF immediately.
© 2023 Lexus, a division of Toyota Motor Sales, USA
L-SB-0032-23
Rev1
May 15, 2023
Page 19 of 30
Brake Squawk/Knock Noise
Repair Procedure (continued)
A. Connect the battery diagnostic tool and check the battery.
NOTE
If brake battery voltage is less than 12.6 volts, the brake bleed procedure in GTS+ may fail.
B. Turn the ignition ON.
C. Shift to the (P) Park position.
D. Ensure the parking brake is ON.
E. Connect Techstream to the DLC3.
F. Turn GTS+ ON and select the following: Chassis – ABS/VSC/TRAC – Reset Memory.
G. Perform the steps as instructed in GTS+.
CAUTION
Once “Delete the Back-Up Memory” is complete, the zero-point memory for the
yaw-rate 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.
H. Select the following in GTS+:
Chassis – ABS-VSC-TRAC – Utility – Air Bleeding.
© 2023 Lexus, a division of Toyota Motor Sales, USA
L-SB-0032-23
Rev1
May 15, 2023
Page 20 of 30
Brake Squawk/Knock Noise
Repair Procedure (continued)
I.
Select “Actuator has been removed” and bleed the brake system by following the
instructions on GTS+.
CAUTION
Add brake fluid so that the fluid level in the brake master cylinder reservoir assembly
does NOT go below the MIN level.
NOTE
If this procedure fails at ANY point, confirm the battery voltage is above 12.6 volts and perform
the following:
Run a Health Check and clear codes.
Disconnect the negative battery terminal.
Disconnect the skid control ECU connector.
Disconnect the brake booster pump connectors.
Wait 10 minutes.
Perform battery boost charge using the battery diagnostic tool.
Reconnect the skid control ECU connector.
Reconnect the negative battery terminal.
Do NOT reconnect the brake booster pump connectors
(Techstream instructs to do this during the air bleeding procedure).
Run a Health Check and clear codes.
Perform accumulator zero down in GTS+.
Perform reset memory in GTS+.
Restart the bleeding procedure from the beginning and follow the instructions in
GTS+ in step 11.J.
© 2023 Lexus, a division of Toyota Motor Sales, USA
L-SB-0032-23
Rev1
May 15, 2023
Brake Squawk/Knock Noise
Repair Procedure (continued)
J. Perform air bleeding per the GTS+ instructions below.
(1) On the “Welcome to the Air Bleeding
Utility” screen, click Next.
Figure 19.
(2) Confirm the conditions shown in
Figure 20 and click Next.
Figure 20.
© 2023 Lexus, a division of Toyota Motor Sales, USA
Page 21 of 30
L-SB-0032-23
Rev1
May 15, 2023
Brake Squawk/Knock Noise
Repair Procedure (continued)
(3) Select “Actuator has been removed”
and click Next.
Figure 21.
(4) Perform the instructions shown in
Figure 22 and click Next.
Figure 22.
© 2023 Lexus, a division of Toyota Motor Sales, USA
Page 22 of 30
L-SB-0032-23
Rev1
May 15, 2023
Page 23 of 30
Brake Squawk/Knock Noise
Repair Procedure (continued)
(5) Loosen the right front bleeder plug and pump the brake pedal until the brake fluid level
in the reservoir tank is at MIN level.
(6) Fasten the bleeder plug and add the fluid until the fluid level in the reservoir tank
reaches MAX level.
(7) Repeat sub steps (5) and (6) twice.
CAUTION
This MUST be done BEFORE proceeding with the instructions in GTS+.
Sub steps (5) and (6) are ONLY done on the right front wheel.
This may require pressing the brake pedal approximately 100 or more times.
If this is NOT done, air may be trapped in the system.
(8) Perform the two steps shown in
Figure 23 and click Next.
Figure 23.
(9) Have you drained the fluid in the master
cylinder reservoir twice as described in
substeps (5) and (6)?
YES — Continue to substep (10).
NO — Return to substeps
(5) and (6).
(10) Pump the brake pedal (depress the
pedal a few times), loosen the front right
bleeder plug with the brake pedal
depressed, and release the pedal
AFTER the plug is fastened. Repeat this
substep 20 times.
NOTE
GTS+ states, “Disconnect the 2 brake
booster pump connectors.” The brake
booster pump connectors should
already be disconnected. The
connectors were disconnected during
actuator replacement and should NOT
have been re-connected.
© 2023 Lexus, a division of Toyota Motor Sales, USA
L-SB-0032-23
Rev1
May 15, 2023
Page 24 of 30
Brake Squawk/Knock Noise
Repair Procedure (continued)
K. Once bleeding the front right and front left is completed select Next and follow the
steps in the figure below for the right rear caliper bleeder plug.
CAUTION
BEFORE this step, add brake fluid so that the fluid level in the brake master cylinder
reservoir assembly does NOT go below the MIN level.
Figure 24.
NOTE
If this procedure fails at ANY point, confirm the battery voltage is above 12.6 volts and perform
the following:
Run Health Check and clear codes.
Disconnect the negative battery terminal.
Disconnect the skid control ECU connector.
Disconnect the brake booster pump connectors.
Wait 10 minutes.
Perform battery boost charge using the battery diagnostic tool.
Reconnect the skid control ECU connector.
Reconnect the negative battery terminal.
Do NOT reconnect the brake booster pump connectors (GTS+ instructs the tech
to do so during the air bleeding procedure).
Perform a Health Check and clear codes.
Perform accumulator zero down in GTS+.
Perform reset memory in GTS+.
Restart the bleeding procedure from the beginning and follow the instructions in
GTS+ in step 11.J.
© 2023 Lexus, a division of Toyota Motor Sales, USA
L-SB-0032-23
Rev1
May 15, 2023
Brake Squawk/Knock Noise
Repair Procedure (continued)
L. AFTER the solenoid is moved for
40 seconds to discharge brake fluid,
fasten the right rear bleeder plug, release
the brake pedal, and select Next.
Figure 25.
M. Add brake fluid so that the fluid level in the
brake master cylinder reservoir assembly
does NOT go below the MIN level.
N. Follow the steps in Figure 26 for the rear
left bleeder plug.
Figure 26.
NOTE
The bleeder should be left open for
30 seconds.
O. When complete, select Next.
© 2023 Lexus, a division of Toyota Motor Sales, USA
Page 25 of 30
L-SB-0032-23
Rev1
May 15, 2023
Page 26 of 30
Brake Squawk/Knock Noise
Repair Procedure (continued)
P. Add brake fluid so that the fluid level in the brake master cylinder reservoir assembly does
NOT go below the MIN level.
Q. Follow the steps in Figure 27 for the rear
right bleeder plug.
Figure 27.
NOTE
The bleeder should be left open for
30 seconds.
R. When complete, select Next.
© 2023 Lexus, a division of Toyota Motor Sales, USA
L-SB-0032-23
Rev1
May 15, 2023
Brake Squawk/Knock Noise
Repair Procedure (continued)
S. Depressurize the accumulator by repeating five times the steps in Figure 28.
Figure 28.
T. Select Exit to complete the air bleeding.
Figure 29.
© 2023 Lexus, a division of Toyota Motor Sales, USA
Page 27 of 30
L-SB-0032-23
Rev1
May 15, 2023
Page 28 of 30
Brake Squawk/Knock Noise
Repair Procedure (continued)
12. Perform the GTS+ Active Test “Actuator Air Bleeding Pattern” to forcefully move the valve in
the actuator to complete air bleeding by selecting the following in GTS+:
Chassis – ABS-VSC-TRC – Active Test – Actuator Air Bleeding Pattern
Figure 30. GTS+ Screen Image (Actuator Air Bleeding Pattern)
Refer to TIS, applicable model and model year Repair Manual:
2016 – 2018 RX 450h and 2018 RX 450hL:
Brake – Brake Control/Dynamic Control System – “Brake Control / Dynamic Control
Systems: Brake Actuator: On-Vehicle Inspection”
2019 – 2022 RX 450h and RX 450hL:
Brake – Brake Control/Dynamic Control System – “Brake Control / Dynamic Control
Systems: Brake Actuator: On-Vehicle Inspection”
© 2023 Lexus, a division of Toyota Motor Sales, USA
L-SB-0032-23
Rev1
May 15, 2023
Page 29 of 30
Brake Squawk/Knock Noise
Repair Procedure (continued)
13. Turn ON the Actuator Air Bleeding Pattern by
selecting the arrow in the Actuator Air Bleeding
Pattern popup window.
Figure 31.
NOTE
Perform the above operation five times.
This operation takes approximately
one minute to complete each time it
is performed.
14. In GTS+ select the following: Chassis – ABS/VSC/TRAC – Reset Memory and perform the
steps as instructed in GTS+.
15. Ensure the parking brake is OFF.
NOTICE
If the parking brake is NOT OFF, the initialization and calibration of the linear solenoid valve
will fail.
16. Perform initialization and calibration of the linear solenoid valve and the yaw rate sensor.
NOTE
BEFORE air bleeding, the linear valve offset learning and brake pedal stroke sensor zero-point
value memories were deleted. ONLY the linear valve offset learning and brake pedal stroke sensor
zero-point learning should be performed.
Refer to TIS, applicable model and model year Repair Manual:
2016 – 2018 RX 450h and 2018 RX 450hL:
Brake – Brake Control/Dynamic Control System – “Brake Control / Dynamic Control
Systems: Electronically Controlled Brake System: Initialization”
2019 RX 450h and RX 450hL:
Brake – Brake Control/Dynamic Control System – “Brake Control / Dynamic Control
Systems: Electronically Controlled Brake System: Initialization”
2020 – 2022 RX 450h and RX 450hL:
Brake – Brake Control/Dynamic Control System – “Brake Control / Dynamic Control
Systems: Electronically Controlled Brake System: Initialization”
© 2023 Lexus, a division of Toyota Motor Sales, USA
L-SB-0032-23
Rev1
May 15, 2023
Page 30 of 30
Brake Squawk/Knock Noise
Repair Procedure (continued)
17. Check and clear ANY DTCs.
Refer to TIS, applicable model and model year Repair Manual:
2016 – 2018 RX 450h and 2018 RX 450hL:
Brake – Brake Control/Dynamic Control System – “Brake Control / Dynamic Control
Systems: Electronically Controlled Brake System: DTC Check / Clear”
2019 RX 450h and RX 450hL:
Brake – Brake Control/Dynamic Control System – “Brake Control / Dynamic Control
Systems: Electronically Controlled Brake System: DTC Check / Clear”
2020 – 2022 RX 450h and RX 450hL:
Brake – Brake Control/Dynamic Control System – “Brake Control / Dynamic Control
Systems: Electronically Controlled Brake System: DTC Check / Clear”
18. Turn the ignition OFF.
19. Disconnect the Techstream from the DLC3.
20. Inspect for brake fluid leakage.
21. Inspect and adjust the amount of the brake fluid.
Refer to TIS, applicable model and model year Repair Manual:
2016 – 2022 RX 450h and 2018 – 2022 RX 450hL:
Brake – Brake Control/Dynamic Control System – “Brake System (Other): Brake Fluid:
On-Vehicle Inspection”
22. Install the brake master cylinder reservoir filler cap assembly.
23. Test-drive the vehicle to confirm the squawk/knock noise is no longer present.
- 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...
Last update on 2026-06-21 / Affiliate links / Images from Amazon Product Advertising API
If the PDF is very large, it may not load in the preview below.
Some older TSBs had multiple PDFs — visit the NHTSA Website to view all PDFs.
If the TSB PDF does not show, download or view it on the NHTSA Website.
Click on the (+) Plus Sign
Then Click on Associated Document(s)
Search NHTSA Database for Recalls
Search NHTSA Database for Vehicle Investigations
View Latest Vehicle Investigations
Search NHTSA Database for Vehicle Complaints
View Latest Vehicle Complaints
TSB/Document ID: L-SB-0032-23 Rev
Replacement Service Bulletin Number:
MFR Communication Date: 2023-10-02
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 |
- 🏆【2026 TOP OBD2 Scanner Diagnostic Tool】OTOFIX D1 Lite wireless obd2 scanner has upgraded hardware configuration and car coverage. The newly upgraded D1 Lite with 🔥OS Android 9.0🔥1.5Ghz 4 core high efficiency processor🔥2GB RAM
+64GB ROM large storage🔥5800mAh large battery, more stable and longer lasting diagnostics🔥 38+ Reset🔥action tests🔥full system diagnostic🔥Supports MV105 endoscope🔥21+ Language Supports🔥100000+ vehicle coverage to meet all your daily maintenance needs. - 👍【Bi-Directional Control / Active Test】D1 Lite obd2 scanner has bidirectional control(worth $300+), which is the most beloved feature among mechanic. If your headlights or car windows are broken, going to a repair shop will cost a lot of money. You can use D1 Lite to send execution commands to the ECU module and identify the repair status. Such as ABS, car windows, doors, valves, wipers, headlights, etc., effectively shorten diagnostic time and reduce diagnostic costs.
- 🔥【All Systems Diagnostics, In-depth Checking】This advanced OBD2 Scanner D1 Lite can perform OE-level diagnosis of all systems including engine, transmission, airbag, ABS, ESP, TPMS, gateway, steering, radio, and air conditioning for more than 100 brands. This diagnostic scanner supports essential functions, such as reading ECU version info, reading and clearing fault codes, and reading data streams.With just a simple click, it provides you with accurate and in-depth diagnostics.
- 🏆【38+ Reset Hot Functions】For repair workshops, holding an OTOFIX D1 Lite Auto scanner is a strong advantage over others. Its 38+ maintenance functions provide various solutions for all module repairs, including Oil Reset, TPMS Reset, Injector Coding, Suspension, Throttle Matching, etc., which will usher your repair business to a new pinnacle. Continuously updating will never make the functionality & compatibility out-of-date.
- 🏆【150+ Models, 10000+ Car Coverage & 16 Languages】D1 Lite is a comprehensive car diagnostic scan tool, help you to troubleshoot car issues fast for 95% US, European, Asian auto makes. ✅ With frequent updates and optimizations allow D1 Lite to cover more vehicles to meet your needs. ✅ Multilingual menu allows auto mechanics around the world to use it without language barriers. 🚩Note: Kindly send us the S/N of the device to authorize new language updates before changing the menu language.
- 🎉[OTOFIX D1 Lite, Perfect Cost-effective Diagnostic Tool]: OTOFIX D1 Lite, a newest bidirectional scan tool from OTOFIX company, is a great choice for DIYers and repair shops. 👉This obd2 scanner diagnostic tool packs all practical functions: OE level all systems diagnoses, Bi-Directional Control, 38+ reset services fixing 99% of common problems, support DoIP & CANDF protocols and FCA AutoAuth, high-end hardware configuration. Worldwide vehicles and 🔥2 Years Free Updating🔥 covered.
- 🎉[Bi-Directional Scan Tool, Active Test]: OTOFIX D1 Lite bluetooth obd2 scanner can also command ECUs and monitor the operation of the actuators to track down the problems of certain parts, like windows, sunroof, wipers, fuel pumps, etc., saving repair time & trouble. This makes OTOFIX D1 Lite the most cost-effective bidirectional scan tool.
- 🎉[2026 Newest, 38+ Hot Reset Functions]: Equipped with 38+ reset functions in one, the OTOFIX D1 lite automotive scanner diagnostic tool allows you to troubleshoot 99% of common vehicle problems. You can use this car diagnostic scanner holding enough functions to easily repair common vehicle models in your repair shops. Including Oil Reset, Injector Coding, Throttle, DPF Reset, SCR Reset, Gear Learning, Clutch Learning, Suspension, etc. Note* Reset functions vary by model.
- 🎉[OE Level Full Systems Diagnostics]: Unlike the 2-system and 4-system diagnostic tools, the OTOFIX auto scan tool can complete comprehensive system diagnostics within 5 minutes. It accesses and scans all available onboard systems like for Engine /AT /ABS /EPB /BMS /TPMS /SRS /SAS /Audio System /BCM /Air Conditioning / etc., to read & clear codes, view live data, and check ECU information. Note: Active test is not involved.
- 🎉[Powerful Hardware Configuration]: Designed with a fashion appearance & a 7” touchscreen and a weight of 463g, this OTOFIX D1 Lite OBD2 diagnostic scanner scan tool is convenient for everywhere and easy to use & store. Android9.0 OS and 2+64GB memory enhance multi-task smoothness and diagnostic operation, no more wasting too much time. 5800mAh battery allows hours-lasting use. WiFi & VCI1 also bring faster communication for your diagnostics.
- 2026 Newest Wireless Bluetooth Scan Tool D1: OTOFIX D1 Diagnostic scanner is upgraded version with Enhanced Hardwares & Newest Functions, FASTER and SMARTER! ✅Alternative Bluetooth 5.0 +USB connect✅2G+64GB✅Android 9.0 OS✅5G & 2.4 GHz Dual WiFi✅5800mAh battery👍VAG Guided Function👍ECU Online Coding👍CANFD&DOIP👍40+ Services👍Bi-Directional Control👍Full Systems Diagnose👍2 Years Free Update👍150+ Vehicle Coverage🎁Contact to get gift: otofixaftersales-amz@ outlook.com
- ECU Coding to Unlock the Hidden Features: OTOFIX D1 obd2 scanner diagnostic tool newly adds ECU Coding which can Online Coding(ONLY for VW/Au.di/Sk0da), Variant Coding/Offline Programming, Flash Hidden Functions, Reset Adaptive Data, Match Replaced Components, Customize OE-Settings. Such as: halogen fog lamps retrofitted with xenon fog lamps, different capacity battery retrofit, disbale auto start-stop, sunroof initialization, injector calibration, etc. PS: Coding functions vary by model&year.
- Full Bidirectional Control for Active Car Tests: The D1 OTOFIX scanner also offers bi-directional control, allowing you to perform powerful active tests on car subsystems. This means that you can check the working status and functionality of open & close solenoids, energize injectors, turn cooling fan on & off, and more, all from the device itself.🚩The D1 bi-directional obd2 scanner can quickly help you to check if a system or component goes well,Improving 200% Efficiency.**Note that Active Tests available depend on the make/model/year of your car.
- 40+ Popular Maintenance Functions: OTOFIX D1 obd scanner for car performs 40+ hot services, including Oil Reset, EPB, TPMS, BMS, E.GR, G.PF, D.PF, SAS Calibration, ABS Bleeding, Injector Coding, Gearbox Match, Suspension, Crankshaft Relearn, Power Balance, etc., still growing. Great choice for DIYers, technician, repair shop. 🚩Get MORE special functions from "Car Brand>System>Service". Check compatibility before purchase via 📧 otofixaftersales-amz@ outlook.com.
- OE-Level All Systems Diagnostic + One-Click AutoVIN & AutoSCAN: OTOFIX D1 scanner automotriz gives you the ability to troubleshoot entire car systems including engion system,transmission system,body system,chassis,etc. 🚩One of the standout features of the D1 obd2 scanner diagnostic tool is the one-click AutoVIN & AutoScan function. This feature allows you to quickly and easily scan all diagnosable ECUs with just one click, and identify any problems hidden in your vehicle's systems.
Last update on 2026-06-21 / Affiliate links / Images from Amazon Product Advertising API
This product presentation was made with AAWP plugin.