NHTSA ID Number: 11006647
Manufacturer Communication Number: 21-NA-271
TSB/Document Date: 2024-08-28
Summary
This bulletin advises the technician of a possible kinked coolant hose that might be causing the customers concern of a Malfunction Indicator Lamp (MIL) Illuminated - DTC P026A Set.
Bulletin No.: 21-NA-271
Service Bulletin
Date: August, 2024
INFORMATION
Subject:
Information on Malfunction Indicator Lamp (MIL) Illuminated - DTC P026A
Set
This bulletin replaces PIP5745A. Please discard PIP5745A.
Brand:
Model:
from
to
Escalade Models
2021
2024
Silverado 1500
2020
2021
2022
2022
Silverado 1500 LTD
(RPO J21, VIN Digit 5
= W/Y)
Chevrolet
Silverado 1500 New
(RPO J22, VIN Digit 5
= A/D)
Silverado 1500
2023
Suburban
2021
Tahoe
2021
Sierra 1500
2020
2021
2022
2022
Sierra 1500 Limited
(RPO J21, VIN Digit 5
= 8/9)
GMC
Model Year:
Sierra 1500 New
(RPO J22, VIN Digit 5
= H/U)
Sierra 1500
2023
Yukon Models
2021
2025
VIN:
from
Engine:
to
3.0L (LM2, LZ0)
2025
Important: This technical service bulletin (TSB) can
only be completed by certified repair facilities who have
met all specific training, tool and equipment requirements pertaining to the vehicle Brand and Model
serviced. Repairs must be performed by a technician
who has successfully completed the required training.
Important: Service agents must comply with all
International, Federal, State, Provincial, and/or
Local laws applicable to the activities it performs
under this bulletin, including but not limited to
handling, deploying, preparing, classifying,
packaging, marking, labeling, and shipping
dangerous goods. In the event of a conflict
between the procedures set forth in this bulletin
and the laws that apply to your dealership, you
must follow those applicable laws.
Involved Region or Country
North America, Uzbekistan, Russia, Middle East, Chile, Columbia, Ecuador, Paraguay,
Peru, Uruguay, Japan, S. Korea, Thailand, Australia, New Zealand, Europe.
Condition
Some customers may comment that the MIL is illuminated.
Some technicians may find DTC P026A set in the Engine Control Module (ECM).
Cause
This may be due to a kinked hose at or near the low temperature auxiliary coolant pump.
Copyright 2024 General Motors. All Rights Reserved.
Page 2
August, 2024
Bulletin No.: 21-NA-271
5635568
Correction
If this condition is encountered, loosen the hose clamp and rotate the hose to allow for
proper coolant flow.
5635679
Version
4
Modified
Released November 19, 2021
Revised November 09, 2022 - Added 2023 Model Year and Important statements.
Revised August 01, 2023 - Added the 2024 Model Year and Europe to the involved
regions.
Revised August 02, 2024 - Added 2025 Model Year.
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
- Unsurpassed freeze protection and anti-boil performance...
- Organic acid technology resists rust, scale & corrosion...
- High-quality additives protect against leaks and won’t...
- Pre-mixed orange formula is ready-to-use in a 50/50 ratio...
- 5 year/150,000 mile guarantee protects against engine...
- Formulated to replace the OEM fluid in Asian make vehicles...
- 5 year/150, 000 mile . Silicate-free, long-life, phosphate...
- The long life formula provides protection for all cooling...
- Meets the following OEM and industry specifications: JIS K...
- Note: Please check the vehicle specification before...
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: 21-NA-271
Replacement Service Bulletin Number:
MFR Communication Date: 2024-08-02
MFR Internal Campaign ID/Software Version:
Communication Type: Service Bulletin/Repair Instructions
NHTSA Components: ENGINE
MFR Component System:
MFR Component Subsystem:
Previous TSB | Next TSB |
- [Notice] When you receive a used escaner automotriz device, it may be a customer return resold by Amazon without inspection. You can exchange it for a new one through Amazon. As this situation is unavoidable, we sincerely apologize. For any issues, contacting us via Amazon's "Messages" is the best way, and we’ll provide a solution within 24 hours. THINKSCAN 689BT Can Be Used Immediately After It is Turned On, Without Complicated Registration Process, Which is More Convenient & Quick.
- [Good News] THINKSCAN 689BT is the most competitive automotive scan tool to date, offering wireless updates with no subscription fees(valued 500Buc.ks) . With all the features of THINKTOOL PD8,PRO, built on Android 10 platform with 4-core CPU, 4GB RAM
and 64GB ROM, serving up to 5X faster than older MAX/MINI/PLUS vehicle scanners escaner automotriz, no more slow and delayed feedbacks, it's time to update your garage tool. - [Big Money Saver] Premium THINKSCAN 689BT Wireless Diagnostic Scanner Escaner Automotriz, save up to 400USD per year, includes all useful features: Full bi-directional controls, ECU coding, 34+ services, OEM all system diagnostics, Worldwide vehicles coverage, CAN FD & DoIP, FCA AutoAuth（The 689BT only provides a login and purchase portal, and users are required to register for an FCA account and pay a membership fee in order to perform the relevant automotive diagnostics)
- [3000+ Active Tests]Active testing is one of the most useful features in automotive maintenance and greatly improves mechanic efficiency. THINKCAR 689BT bidirectional scanner can send action commends to vehicle sub-systems or components for active test without using vehicle controls. It can perform various tests such as: EVAP Test, Fuel Trim Reset, Injector Buzz Test, Window/ Mirror/ Door Lock Test, Pump and Value Tests, etc. Get functions from "Diagnose>Car Model>System>Active Test".
- [Hot Advanced Features] 689BT bidirectional tool scanner for car newly adds ECU Coding, Power Balance, Flash Hidden Functions, Reset Adaptive Data, Match Replaced Components, Customize OE-Settings. Such as: 1. changing the color of interior lights 2. switching on/off the auto hold, 3. customizing dash kits 4. activating the auto side mirror folding function 5. disables auto start-stop. Note: Coding functions vary by model&year.
- 【Cost-effective OBD2 scanner】 Thinkcar Thinkdiag2 is the most powerful wireless diagnostic tool for it's price! Equipped with multi-functions of Newly added CAN-FD protocol, BiDirectional control(Active Test), 15 Maintenance resets, All Systems diagnosis, Auto VIN, FCA AutoAuth, Unlock the protected FCA vehicle SGW module on Chrysler, Dodge, Jeep, Alfa Romeo, and Fiat vehicles manufactured after 2019.120+ Car brands coverage, No IP limited, etc. Good for workshops & DIYers. Kindly send us VIN to check compatibility before purchase
- 【OE-Level Full Systems Car Scanner with Added CAN FD Protocol】 Upgrade of Thinkdiag, Thinkdiag2 is a bluetooth diagnostic tool can diagnose Full System such as ECM, ABS, SRS, TCM, EPB, TPMS, SAS, A/C, BMS, etc. Thinkdiag2 can read/clear fault codes, read real-time data, read control module information,etc. As the only diagnostic scanner in this price range that supports the CAN-FD protocol, it suits for the latest GM(2019-) , saving $100 to buy a CAN FD adapter, reducing the risk of undetected errors to enhancing the user experience
- 【Bidirectional Test】This bidirectional scan tool Thinkdiag2 allows you to send commands from your smartphone directly to the vehicle's ECU for active testing, quickly locate problem areas, such as A/C clutch, windows, doors, sunroof, etc., reducing the diagnostic time and money. (Note: kindly send us VIN to check compatibility before order.)
- 【15+ Maintenance Functions】Thinkdiag2 OBDII code scanner is designed for individual car owners, DIYers, and small repair shops, which has a separate menu of 15 common special functions, such as Oil reset, EPB reset, SAS calibration, ABS bleeding, injector code, TPMS reset, etc. Enter from the all-system diagnostic menu to unlock more system special functions, and effectively handle the reset and relearn of most cars. Note: The Maintenance functions that each car can do may be different
- 【120+ car brands & FCA Autoauth+10 languages】Thinkcar thinkdiag2 helps you to troubleshoot the problems fast for 100 + US, European, Asian vehicle brands after 1996 that use the OBDII protocol. Only support 12V cars, including gasoline cars and diesel cars. Supporting Autoauth allows you to unlock the protected FCA vehicle SGW module on Chrysler, Dodge, Jeep, Alfa Romeo, Fiat vehicles, etc. (Note: Only provide AutoAuth login portal, and need purchase the registration number on the AutoAuth website by yourself.) Multilingual function allows workshop mechanics to avoid language barriers and use it around the world Without restriction
- 【15+ Advanced Reset & Calibration Functions】The Thinkdiag scanner provides 15+ professional maintenance functions, including:✔ Oil Reset | ✔ ABS Bleeding | ✔ Injector Coding | ✔ SAS Reset✔ TPMS Reset | ✔ BMS Reset | ✔ Transmission Adaptation | ✔ AFS Reset | ✔ Sunroof Calibration | ✔ Brake Reset | ✔ Suspension Relearn | ✔ Electronic Throttle Relearn | ✔ Seat Calibration | + More reset/relearn/calibrate/adaptive functions under automotive full systems diagnostic menu. Ideal professional OBDII scanner for mechanics and DIY enthusiasts, Thinkdiag delivers professional OE-level diagnostics with adaptive relearn capabilities for precise vehicle servicing.
- 【Full-System Diagnostics OBD2 Scanner Bluetooth】 Thinkdiag OBD2 Scanner supports all Systems diagnostic function, it can read/clear DTCs, read live data, read control module information, actuation tests and maintenance functions for ECM, BCM, SRS, TCM, BMS, TPMS, SAS, A/C system etc... It works with most car models after 1996, cover more than 120+ car brands. All car make and reset software come with 1 year update without any charge, much valuable and powerful than 1000 dollars level scanners in the market.
- 【Potential Feature Activation】 Thinkdiag diagnose obd2 scanner Bluetooth allows you to match the replaced components with ECU, activate potential functions for BMW, for GM, for Benz etc. Adjust some annoying features, adapt vehicle's settings to improve performance. No matter you are private owner or professional technician, Thinkdiag is a powerful and handy scanner in your repair tool list. Potential features are not suitable for every car models, please check with us before purchase. This superior function required newest Android OS device, it performs better on Android cell phone.
- 【Bidirectional Test/Active Test】 Thinkdiag car code reader actuates solenoids and actuators for active testing, send commands to systems/components to test their real-time working status, without using manual vehicle controls which saves much diagnostic time and effort to identify malfunction causes. You can check windows, doors, mirrors, sunroof, fans, fuel pump and other parts working status by actuation test function, thinkdiag supports 10000+ active tests. When you process Automotive full system diagnostic, you can do active test on every supported module.
- 【Intelligent Diagnostic Tool with Auto-VIN】Thinkdiag Bluetooth OBD2 scanner makes your smart phone device become a professional vehicle diagnostic tool, it compatible with Android and iOS system. Auto-VIN function supports the Thinkdiag identifies the most car models automatically, if autovin failed, you can choose car info manually. Full system Vehicle health report will be automatically created after diagnosis, report can be shared. Live Data Stream combined 4-in-1 Graphing+Data Record better for monitoring vehicle performance and analyze the abnormal parameter.
Last update on 2026-06-21 / Affiliate links / Images from Amazon Product Advertising API
This product presentation was made with AAWP plugin.