NHTSA ID Number: 10239076
Manufacturer Communication Number: 20-NA-182
TSB/Document Date: 2023-07-11
Summary
This service bulletin provides a procedure to replace the brake line pressure switch to correct a customer concern of a brake booster pump motor that runs at all times even after the ignition is turned off.
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)
- Nickel-copper alloy is very flexible making for super easy...
- Corrosion and Rust Resistant: Copper-nickel alloy resists...
- SAE and ISO Certified: This tubing is tested and verified to...
- Complete Kit with 16 Inverted Flare Fittings: Includes 25 ft...
- Ideal Replacement for Steel Brake Lines: Copper-nickel brake...
- PACKAGE INCLUDE - MuHize Brake Line Kit Replacement with...
- SUPER EASY BENDING & FLARING - MuHize brake lines are easy...
- HIGHER QUALITY - MuHize brake lines are made with unique...
- WIDELY APPLICATION - MuHize 3/16 brake line tubing kit...
- PROFESSIONAL - MuHize focus on outstanding features and...
This product presentation was made with AAWP plugin.
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: 20-NA-182
Replacement Service Bulletin Number:
MFR Communication Date: 2023-06-22
MFR Internal Campaign ID/Software Version:
Communication Type: Service Bulletin/Repair Instructions
NHTSA Components: SERVICE BRAKES
MFR Component System:
MFR Component Subsystem:
Previous TSB | Next TSB |
Service Bulletin
Bulletin No.:
20-NA-182
Date:
June, 2023
TECHNICAL
Subject:
Brake Booster Pump Motor Runs at All Times Even After Ignition Turned Off - DTC
C0021 Set
This bulletin replaces PIT5719. Please discard PIT5719.
Brand:
Model:
Silverado 4500HD,
5500HD, 6500HD
Model Year:
VIN:
from
to
from
to
2019
2022
-
-
Engine:
-
-
Involved Region or Country
North America
Condition
Some customers may comment that the brake booster pump motor runs at all times even
after the ignition is turned off.
The technician may find DTC C0021 (Brake Booster Performance) set in EBCM.
Cause
The brake pressure switch may stick open.
Copyright 2023 General Motors
LLC. All Rights Reserved.
Page 2
June, 2023
Bulletin No.: 20-NA-182
Correction
4961493
Replace the Brake Master Cylinder Pressure Sensor (3) with new updated part number.
Service Procedure
Refer to Brake Master Cylinder Pressure Sensor
Replacement in the Service Manual.
Parts Information
Causal
Part
Description
Part
Number
Qty
X
Switch Asm.
Press
1
Bulletin No.: 20-NA-182
June, 2023
Page 3
Warranty Information
For vehicles repaired under warranty, use:
Labor Operation
Description
Labor Time
2441460
Brake Master Cylinder Pressure Sensor Replacement
Use the Published Labor
Operations Time
Version
2
Modified
Released September 16, 2020
Revised June 22, 2023 - Add 2021 and 2022 to Model Year and Update Part Number
GM bulletins are intended for use by professional technicians, NOT a "do-it-yourselfer". They are written to inform these
technicians of conditions that may occur on some vehicles, or to provide information that could assist in the proper
service of a vehicle. Properly trained technicians have the equipment, tools, safety instructions, and know-how to do a
job properly and safely. If a condition is described, DO NOT assume that the bulletin applies to your vehicle, or that your
vehicle will have that condition. See your GM dealer for information on whether your vehicle may benefit from the
information.
WE SUPPORT VOLUNTARY
TECHNICIAN
CERTIFICATION
- 💝【Questions? We’re Here Anytime】MK808S is a high-end flagship model that connects via wired OBD2 for faster, more stable, and reliable diagnosis compared to B,.T tools. If you have any questions about setup, activation, features, additional accessories, or update subscriptions, please reach us and we will respond promptly to assist you. It includes 1-Year F.ree Updates (124.5 bucks/year after), and most functions still work after expiration except a few online features. Please note some functions like full TPMS are not supported, reach us for model recommendations.
- 🔥🔥🔥【2026 NEWLY RELEASED BI-DIRECTIONAL CONTROL】As the 2026 upgraded version of MaxiChek MX808 MaxiDiag MD909 Pro MD906 Pro, our Newest MK808S auto diagnostic scanner for all cars inherits the powerful Bi-directional Control which makes it the most cost-effective scanner (without breaking the bank, same as MK900BT MS906 PRO MS906MAX). Active test is widely used on car subsystems to help you check if the car actuators are all in good condition. Such as windows, rear mirrors, sunroof, wipers...
- 【28+ MOST POPULAR RESET SERVICE FOR 150 MAKES】Autel versatile OBDII scanenr MK808S, full level-up of MX808, work as MX900, MK900, MK900-BT, supports 150+ car brands worldwide. Like the OBD2 code reader MaxiCOM MK808BT Pro, MK808S is equipped with 28+ hot services including 0il Reset, SAS Calibration, ABS Bleeding, Battery Registration, etc. MK808S ranks top in professional automotive tablets and keeps updating to support more newer modes from 2025 to 2026.
- 【ALL SYSTEM DIAGNOSTICS, FACTORY-LEVEL SCANNER】The MK808S dealer-level scanner, like Snap-on tools, effectively works all cars for all system diagnostics. It reads/clears codes, displays 5-in-1 Live Data, performs active tests, and special functions for all available modules. With a few clicks, you can easily understand the vehicle's condition. The convenient Wi-Fi printing feature allows you to generate a detailed report, highlighting the exact nature of the problem.
- 【AUT0 SCAN & AUT0V1N, 10X FASTER】How much have you spent on car maintenance? Even a minor issue can take up a significant amount of time. The MK808S is designed to improve your work efficiency. With its Aut0V1N technology, you can check your car's make, model, and year information with just one click. The Aut0Scan feature automatically scans all of the vehicle's modules and detects any fault codes. Check Aut0V1N compatibility by reaching us at 📞1-833-436-5880. Available Mon-Fri, 9 AM-6 PM EST.
- 💯【Conta.ct us for Support Directly】If you met any issues about: Received a registered device/ Language Changing/ Function not Support/ Blueto-oth connector malfunction/ Subscription Renewal, please conta.ct us via 📞autelsupply @outlook. com🛣️, we will provide perfect solution for you. ⚠️Note: Autel MK900BT comes with 1-Year Free Software Update, most features will remain active after update subscription expires. For questions regarding updates or need more useful accessories, please conta.ct us via 📞autelsupply @outlook.com🛣️. 2. If you encounter Blueto-oth adapter VCI150 malfunction, please tell us 📞autelsupply @outlook. com🛣️, we will handle it promptly.
- 🔥🔥🔥【2026 AUTEL FLAGSHIP MK900BT MK900-BT, NEW MODEL OF MK808S MK900 MX900 MK808BT MX808S】2026 newest Autel MK900BT retains all features of MK808S MX900 MX808S MK808Z MK808Z-BT MK808K-BT, while EXTRA added powerful functions (value 2000+ bucks). The Pro-level Autel MK900BT makes a big leaps: 28+➡40+, 50+➡3000+ Active Tests, 2026 NEW✅CAN FD & DOIP protocols ✅Pre&Post diagnostic report ✅WIFI Print ✅Auto VIN&Auto Scan 2.0 ✅Scan VIN/ License ✅Battery Test (Need purcha.se BT506). If found defect or us.ed, please conta-ct 📞autelsupply @outlook. com📞 get perf-ect solut.ion.
- 🚗【3000+ ACTIVE TESTS (50➡3000+), SAME AS MS906 PRO】Differ from MS906BT MS906 MP808 MK808 MX808 MK808BT only 50 tests, Autel scanner MK900BT escaner automotriz professional offers 3000+ active tests, it can send command to ECUs & monitor actuators operation, quickly locating faulty components. Bidirectional scanning takes your diagnostics to the next level with menu lists 3000+ active tests, such as windows, rear mirrors, sunroof, wipers, fuel injector, coolant fans, radiator fan, AC clutch, coolant pump and more. Note: Functions are not available for all vehicles, please send vehicle VIN to us check compatibility.
- 🚗【40+ HOT SERVICES FOR 150 MAKES (28+➡40+)】Full level-up of OBD2 code reader MaxiCOM MK808S MK808 MK808Z MX808 MK808Z-BT with 28 service, Autel scan tool MK900BT/ MK900-BT offers 40+ maintenance service on 150+ brands 10,000 vehicles from 1996-2025-2026. Hottest Services like: Oil Reset, ABS Bleed, SAS Calibration, Injector Coding, SRS, Throttle Reset, Gearbox Reset, Battery Registration etc. Added 12+ advanced resets: rain slash light sensor reset, HVA.C/ SUS calibration etc. Welcome to send Vehicle Make>Model>Year>VIN>Functions you required to 📞autelsupply @ outlook . com📞 check compatibility.
- 🚗【OE ALL SYSTEM DIAGNOSE, AUTO SCAN 2.0: SCAN LICENSE/ AUTO VIN】2026 new release Autel MaxiCOM MK900-BT scan tool embodies all system diagnostic with its 8in display for all vehicles. Like Sna.p-on tools, it can perform ✔Read/Clear Codes✔Displays 5-in-1 Live Data✔Record & Playback Data✔Retrieve Info on all available systems like ABS ECM BCM SRS TCM etc. In addition to Auto VIN technology, Autel MK900BT adds Scan License/ Auto Scan 2.0 to identify vehicle’s VIN/ license, make, year, model, no need manual input; One-click WiFi Printing of Pre&Post comparison diagnostic reports, highlight root causes of problems.
- 【TURN OFF CEL】 This AL319 car scanner diagnostic tool supports Reading and Clearing DTCs, DTC Look Up, displaying Live Data, Freeze Frame & I/M Readiness, view vehicle information, etc., to figure out the root cause of the Check Engine Light (CEL) and turn it off, helping you catch any potential issues early and avoid excessive costs from unnecessary repairs.
- 【EXTENSIVE APPLICATION】 Autel AL319 Compatible with 7 languages (English, French, Spanish, etc.) and various post-1996 OBD II protocol vehicles (Toyota
, Nissan, Honda, Ford, etc.), this OBD II scanner provides accurate and fast diagnosis for worldwide car owners. - 【FOR END USER & DIYERS】 This error code reader AL319 is “plug and play” and comes with an easy interface. Even if you’re not familiar with vehicle repair, you can quickly take control of this obd2 scanner, and get the information you want.
- 【USER-FRIENDLY DESIGN】 This OBD2 scanner and check engine code reader features a patented One-Click I/M Readiness, TFT color display, built-in speaker, LED Indicator etc. The cable is long enough without being too long and getting in the way. No batteries are needed.
- 【HIGH-QUALITY SERVICES】 12 months war.ranty from the date of purchase and lifetime free update are offered by this Automobile OBDII scan tool. Welcome to contact us via Q&A, email, or hotline, and our after-sale-service team for technical support.
This product presentation was made with AAWP plugin.
Last update on 2026-05-13 / Affiliate links / Images from Amazon Product Advertising API