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NHTSA ID Number: 10205586
Manufacturer Communication Number: 21NA267
Summary
This bulletin advises the technician of a possible location that a leak may occur from the SCT pipe.
Condition
Customer concern of smoke or exhaust fumes/odor in the cabin or exhaust fumes/odor outside the cabin.
Cause
This condition may be caused by an improper weld on the Exhaust Back Pressure Valve.
Correction
Test for a leaking exhaust backpressure valve weld joint using the Power Smoke diagnostic leak detector (GE-52250 – refer to the latest version of PIP5684).
- Please note, smoke from the tester may not get through the DPF, so test downstream by administering the smoke at the fitting on the tailpipe bladder seal.
Important: Be certain to remove the duct tape from the exhaust cooler after testing.
- Also, the tailpipe bladder seal doesn’t reach the exhaust cooler so use duct tape around the pipe to seal the cooler holes.
Repair this or any other leaks as necessary.
Refer to the pictures below and inspect the weld joint on the Exhaust Back Pressure Valve:
Note: If the weld joint is leaking, replace the Exhaust Back Pressure Valve.
- The exhaust backpressure valve is located between the downpipe from the SCR w/ filter and the under floor SCR.
A leak may be caused by an ineffective weld, allowing for a leak at the flange joint.
- Soapy water can be used to identify the leak, though smoke from the GE-52250 is also effective.
10 Affected Products
Vehicles
| MAKE | MODEL | YEAR |
CADILLAC | ESCALADE | 2021 |
| CADILLAC | ESCALADE ESV | 2021 |
| CHEVROLET | SILVERADO 1500 | 2020-2021 |
| CHEVROLET | SUBURBAN | 2021 |
| CHEVROLET | TAHOE | 2021 |
| GMC | SIERRA 1500 | 2020-2021 |
| GMC | YUKON | 2021 |
| GMC | YUKON XL | 2021 |
1 Associated Document
Manufacturer Communications
Bulletin No.: 21-NA-267
Date: November, 2021
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SaleBestseller No. 1
Solary Automotive Smoke Machine Leak Detector - 12V DC EVAP Vacuum Diagnostic Tester for Pipe System
- Built-in Air Pump: smoke machine features a built-in air pump, eliminating the need for an external air source, allowing you to perform tests anytime, anywhere. Simply add about 20ml of baby oil or Glycerin (oil not included) to start your testing effortlessly
- Multi-Function: Suitable for a wide range of tests, including EVAP systems, vacuum leaks, low-pressure turbo leaks, intake manifolds, cooling/EGR/exhaust systems, and more. It can be used on cars, motorcycles, and various other vehicles
- Quick Detection: The machine generates thick smoke within just 10 seconds of startup, providing enough output to detect even the smallest leaks, ensuring fast and accurate problem identification
- Lightweight and Portable: Weighing only 2.5 kg, the Solary Automotive Car smoke machine is compact, easy to store, and transport, making it an essential tool for every car owner
- User-Friendly: With a simple and intuitive interface, the device has a low entry barrier, making it easy for even first-time users to quickly get started
SaleBestseller No. 2
AutoLine Pro EVAP High Volume Smoke Machine Leak Tester with Built-in Air Pump - Shop Series Plus - Automotive Smoke Tester for Vacuum Leak Detection - Ceramic Smoke Coil and Best Ranked Smoke Fluid
- 【NEW BUILT-IN AIR MOTOR】No need for a separate air supply!
- 【HIGH PERFORMANCE, PREMIUM BUILD】Made in the USA. Solid Thick Metal Construction for durability. Equipped with our brand new AutoLine Pro Ceramic Smoke Coil and Top Rated Smoke Fluid that outputs LOTS OF SMOKE and last a Lifetime.
- 【PRECISE AND SAFE】Engineered 100% safe for all vehicles. Thick Smoke output detects even the smallest leaks.
- 【SIMPLE TO USE】(1) Fill with the included OEM Approved or Any Smoke Fluid. (2) Turn on the Built-In Air Motor. (3) Start smoke diagnostics!
- 【OEM APPROVED SMOKE FLUID INCLUDED!】 Safe for all systems and sensors. 800 Min Premium High-Smoke output formula. We’ve included plenty of fluid so you can focus on what’s important. ( Other brand's smoke machine just comes with EMPTY bottle)
Bestseller No. 3
AutoLine Pro HyperSmoke™ Automotive Smoke Machine EVAP Vacuum Leak Tester – Adjustable Pressure – OEM Approved Smoke Fluid – Built-in Air Compressor Motor – Includes Cone for Vacuum and Exhaust Leaks.
- HyperSmoke Technology – Creates Thick Visible Smoke for Easy Leak Testing. Adjustable Pressure. Infinite Smoke. Instant Warmup. Built-In Air Compressor Motor. OEM Approved Smoke Fluid. Designed and Engineered by AutoLine Pro USA, an American Team of Individuals bringing the latest innovation to you.
- HyperSmoke Versus the Competition – Competitors overheat quickly causing downtime. Competitors do not have EVAP mode and will cause permanent damage to EVAP systems. Competitors don’t have built-in air and want you to use your own air pump/compressor. Competitors want you to buy baby oil that’s not made for automotive leak testing. Competitors are all overseas with copy-paste parts – To check, click on “Sold By”, scroll down, and check their address. Don’t Let Anyone Catch You Lacking With The Competition!
- Includes Everything You Need – Made for ALL Leak Testing Scenarios - EVAP, Vacuum, Intake, Exhaust, Turbo, Superchargers, EGR, Cooling Systems, Engine Blocks, Oil Leaks, Body Work, Wind & Water Leaks, worn rubber, gaskets, seals, connectors, Cars, Trucks, Tractors, Semis, Motorcycles, Scientific Apparatus, and more!
- OEM Approved Smoke Fluid Included – Safe for all systems and sensors. Premium High-Smoke output formula. We’ve included plenty of fluid so you can focus on what’s important – 240 minutes of runtime!
- Adjustable Pressure – Adjustable Pressure gives you the flexibility to leak test a significantly wider array of systems ranging from EVAP all the way to Turbocharged systems. Why is this feature important? EVAP must be tested at under 1 PSI otherwise DAMAGE WILL OCCUR. This is a feature MISSING from other overseas copy-paste smoke machines.
Bestseller No. 4
Smoke Machine Automotive with Built-in Air Compressor, Professional Smoke Leak Detector for Car, Diagnostic Leak Tester Tools for EVAP, Vacuum, Fuel and More Leak Testing
- 【Comprehensively Detecting Various Types of Leaks】This smoke machine leak detector can produce columnar smoke at the point of leakage, so as to locate the leakage point in the compartment, repairing it in time and improving driving safety. Great for detecting leaks from throttle shafts, engine blocks, turbo test systems, crankcase systems, air intake systems, exhaust systems, fuel tank systems, EVAP systems, EGR systems, cooling systems, and various piping in a wide range of vehicles (including older models).
- 【Safe Car Smoke Tester】This vacuum leak smoke tester automotive is made of thick metal, compact and durable. It has a smart protection device that automatically cuts off the power if the working temperature exceeds the limit value to ensure the safety of the operator and the smoke machine. The device uses baby oil to produce harmless smoke and is perfect for leak detection in the ductwork of all DC12V vehicle types such as cars, motorcycles, snowmobiles, ATVs, light trucks and speedboats.
- 【Complete Leak Detection Adapters & Extra Duct Caps】Our multi-functional vehicle smoke machine includes cone adapters, smoke delivery hoses, air intake bladders that work seamlessly with a wide variety of lines and hoses, making it ideal for checking vacuum, fuel, engine, air intake systems, and more. The additional 7 different sized pipe caps feature a tapered design for a tight seal at the appropriate pipe and are made of high quality automotive grade plastic for durability.
- 【Built-in Air Pump & Fast Smoke Out】This automotive smoke machine has a built-in air pump, no need for additional air connection and external air pump maintenance cost, high efficiency, convenient and money-saving. The built-in air pump's compressor generates 19 to 23 psi of air pressure to easily introduce smoke into the automotive system under test, which can produce a large amount of smoke within 10 seconds, allowing you to quickly and accurately locate leaks.
- 【Accurate Leak Detection and Pressure Decay Test】Built-in adjustable flow meter and pressure gauge allows you to quickly and accurately detect even the smallest leaks, ensuring an accurate diagnosis every time. It also supports pressure decay testing, which identifies tiny leaks by applying a specific pressure and monitoring the pressure gauge, especially for hard-to-find vacuum leaks.
Bestseller No. 5
Aoteda Smoke Machine Automotive Built in Air Pump, EVAP Smoke Machine Leak Tester with Pressure Gauge Flow Meter, SFuel and More Leak Testing，Fuel Pipe Diagnostic Tester for All 12V Cars
- 【Safe Car Smoke Tester】This vacuum leak smoke tester automotive is made of thick metal, compact and durable. It has a smart protection device that automatically cuts off the power if the working temperature exceeds the limit value to ensure the safety of the operator and the smoke machine. The device uses baby oil to produce harmless smoke and is perfect for leak detection in the ductwork of all DC12V vehicle types such as cars, motorcycles, snowmobiles, ATVs, light trucks and speedboats.
- 【Comprehensively Detecting Various Types of Leaks】 Aoteda automotive smoke machine is designed for testing leaks in all DC12V vehicles' pipe systems. It can easily check car sealing, throttle shafts, engine block, turbo test system, crankcase system, intake system, exhaust system, fuel tank system, EVAP system, EGR system, cooling system, various pipe fittings leakage problems.ensuring your vehicle stay in the safe and peak performance.
- 【Adjustable Air Flow Meter & Pressure Gauge】: The leak detector features a built-in pressure gauge and dynamic flow meter, through which the extent of the leak can be seen in real time, ensuring that even the smallest leaks can be detected clearly and accurately.
- 【Smart Protection】The smoke tester has overheat and freeze protection it will be in self-protection state after a long working time to avoid the smoke maker overheated, the indicator light will be off. the maximum temperature limit is 75°C, ture on antifreeze protection at a low temperature of -20°C. If it exceeds the working limit, such as over 75 ℃, it will automatically turn off the power to secure the safety of both the operator and device. Do not fill oil while working.
- 【Air Mode & Smoke Mode】 Automotive smoke detectors have two quick fixes for leaks. The smoke leak detector is designed with independent switch control, and the air mode switch independently controls the built-in air pump, which can help you determine if there is a leak. The smoke mode switch independently controls the smoke generator and can help you locate the leak. The built-in intelligent protection device will automatically turn off the power if the working limit is exceeded, ensuring the safety of the operator and the equipment.
SaleBestseller No. 6
Smoke Machine Automotive Leak Detector,Evap Vacuum Smoke Diagnostic Tester,Pipeline Fuel Leakage Detector Compatible with 12V Vehicles
- 【Why Need It】For example: 1. The rupture of the vacuum hose will cause the mixture to be too thick, the idle speed will increase, the hot car will not start well, the engine will surge during acceleration, the fuel consumption will increase significantly, and the exhaust pipe will emit black smoke. 2. Blocking will cause the idle speed to drift, and the idle speed is easy to stall. 3. Air leakage in the vacuum tube will cause the engine to run weakly
- 【No Air Pump】1. The AUTOOL SDT103 smoke leak detector doesn't come with an internal air pump, so you'll need to connect it to an external workshop air source and a 12V vehicle power supply to bring in the workshop air.2. Turn the flow control dial of the AUTOOL SDT103 smoke leak detector counterclockwise to open the airflow, and then switch on the power at the back of the device. This will start the AUTOOL SDT103 machine, generating smoke. (When adding smoke oil to the AUTOOL SDT103 smoke leak detector, make sure not to exceed 20 ml, and please use baby oil or paraffin oila).
- 【External Flow Meter】You can easily control the air pressure, because the air pressure of each pipe in the car is different. If the air pressure is too high, the pipe will be damaged, and if the air pressure is too low, the leak will not be detected. Therefore, the flow meter is very important to protect your detection system more effectively. Make testing safer
- 【EVAP Detection】American cars that began production in 1996 are equipped with EVAP service ports; in most American cars, the EVAP service port is usually located in the engine compartment, but the EVAP service port of some special models may be located in other locations. Open the plastic cover of the EVAP service port, then use the spool wrench to remove the check valve clockwise, then install the EVAP service port adapter, and introduce smoke from the port into the EVAP leak detection system.
- 【Wide Testing Range】The smoke leak detector can do smoke testing of multiple systems, such as EVAP systems, Intake Systems, Cooling / EGR /Exhaust Systems, Crankcase Systems, Engine Airtightness, Vacuum Leaks, Low Pressure Turbo leaks.Applicable cars, motorcycles, snowmobiles, off-road vehicles, ATVs, light trucks and speedboats boats.
SaleBestseller No. 7
Solary Smoke Machine for Car - DC 12V EVAP Automotive Smoke Tester for Vacuum Leaks
- [Automotive Smoke Machine SD302] Solary SD302 auto smoke machine is a professional machine for automotive pipe system leak detection, will help you find leaks and fix most general smoke leak problems. Supports various systems smoke testing, such as EVAP system, exhaust system, intake system, fuel tank system, engine airtightness, various pipe fittings and so on. Suitable for cars, motorcycles, trucks, off-road vehicles and speedboats boat, ect.
- [Dual Mode] The smoke leak detector has air mode and smoke mode, two modes can be controlled independently. Air mode help you test whether there is a leak in the pipe by injecting air into the pipe, smoke mode help you lacate the leak accuarately. It can output thick smoke within 20s after turning on, thick smoke output detects even the smallest leaks.
- [with Pressure Gauge] The smoke tester automotive has a pressure gauge, by observing the pressure gauge, you can determine whether the pipeline is leaking more quickly and accurately. Usually the pressure gauge value continues to rise, indicating that there is no problem with the pipeline. If the pressure gauge value continues to decrease, Explain that the pipeline leak needs to be repaired.
- [Built-in Air Pump] Solary SD302 smoke machine leak detector has its own air pump and smoke generator, no need to buy additional air machines. We use high-quality materials, after many tests, the smoke created from the machine is non-toxic, don't worry about damage to your body and vehicle, please rest assured to use.
- [ Overheating Protection] The car smoke machine has a smart protector to make it safe to use, if the system detects that the amount of e-liquid in the instrument is insufficient or the continuous working time is too long, the system is overheated, the overheat protection indicator ALARM light will light up, and the smoke will stop outputting until the temperature drops to the normal range, and the instrument will resume work, ensure operator and machine safety.
SaleBestseller No. 8
Evap Smoke Machine Leak Tester - 12V DC Vacuum Smoke Diagnostic with Built-in Air Pump
- [Dual-mode design] This automotive smoke machine leak detector features a dual-mode design, comprising a pressure gauge and a pressure adjustment gauge. The pressure gauge provides real-time monitoring of internal air pressure, while the pressure adjustment gauge allows users to adjust pressure levels as needed.
- [Built-in air pump] The smoke leak detector is equipped with a built-in air pump, eliminating the need for an external air source. This design enhances the machine's convenience and ease of use.
- [Easy operation] Simply add baby oil to start the vacuum leak smoke machine. For initial use, only 10-20ml of baby oil is required. Follow simple steps to generate a large amount of smoke.
- [Safety] The smoke tester automotive comes with overheating protection (+75°C) and cold protection (-20°C), ensuring safety during operatio.
- [Multifunction] Our automotive smoke machine can perform various tests such as: EVAP system test, car sealing test, fuel tank system test, exhaust system test, intake system test and various pipe fittings test, ect. It Could be used on all cars, motorcycles, snowmobiles, ATV, light trucks, boats, etc.
SaleBestseller No. 9
Smoke Machine Automotive Diagnostic Tester - 12V DC EVAP Vacuum Leak Detector for Pipe System
- Built-in Air Pump: EVAP smoke machine leak tester features an integrated air pressure pump, eliminating the need for external air sources. This allows for instant deployment wherever needed, greatly enhancing flexibility and efficiency during on-site work
- Easy Operation: The vacuum leak tester is straightforward to use. Simply add 15-20ml of baby oil, connect to a DC12V battery to power the device, and start. It quickly generates large quantities of smoke with an operating pressure range of 19 to 23 PSI
- Detects EVAP Air Leaks: Suitable for detecting leaks in vehicle pipeline systems such as seals, fuel tank systems, exhausts, and intake systems
- Safety Features: The car smoke machine leak detector is designed with safety in mind, incorporating overheat and anti-freeze protections (-20°C cryo protection, 75°C high-temperature protection), ensuring peace of mind with every use
- Worry-Free After-Sales Service: We provide a 1-year warranty and lifelong technical support. If you encounter any issues during use, please feel free to contact us, and we will respond promptly within 24 hours
SaleBestseller No. 10
ANCEL S3000 PRO Automotive Smoke Machine with Built-in Air Pump and Pressure Gauge. Professional Vehicle Leak Diagnostic Detector Tools Kit for Leaks Test in Vacuum,Fuel,EVAP and Other Cars System
- GENERAL TIPS: ALWAYS CHECK THE OIL LEVEL BEFORE USE. Low oil may cause dry burning, overheating, and trigger thermal protection, temporarily stopping the device. Refill if needed and let the device cool down for best performance
- DETECT EVERY TYPE OF LEAK: Our versatile smoke machine for cars includes multiple vehicle cone adapters, a smoke delivery hose, intake bladder, and full-size automotive cap plugs. It seamlessly fits various lines and hoses, ideal for hassle-free checks on vacuum, fuel, engine, intake system and more
- USER-FRIENDLY AUTOMOTIVE SMOKE MACHINE: Begin your detection with just 4 simple steps using our automotive smoke tester. It's lightweight, portable, and even includes a built-in air pump for on-the-go jobs. Detect leaks effortlessly and elevate your automotive expertise. Don't miss out - revolutionize your auto experience and order this automotive tool today
- VEHICLE-SAFE AUTOMOTIVE SMOKE TESTER: This smoke tester for vacuum leaks is made of thick solid metal, compact, and durable. It features an intelligent protector; if the operating temperature surpasses the limit, it will automatically power off to ensure the safety of both the operator and the smoke machine. This device uses baby oil to produce harmless smoke, perfect for all vehicle leak detection
- SAVE TIME AND MONEY WITH BUILT-IN AIR PUMP: Experience effortless leak detection with our car smoke machine's integrated air pump. No need for external air connections– making it easier to move around and test anywhere. Say goodbye to external air pump maintenance costs. Its all-in-one design ensures high effectiveness across various auto systems. Choose this convenient, cost savings, and versatile auto smoke machine leak detector
Last update on 2025-05-08 / Affiliate links / Images from Amazon Product Advertising API
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Copyright 2021 General Motors LLC. All Rights Reserved.
Service in
Bulletin No.: 21-NA-267 INFORMATION
Date: November, 2021
Subject: Exhaust Fumes Or Odor In Cabin Or In the Engine Compartment
This bulletin replaces PIP5780. Please discard PIP5780. Brand: Model:
Model Year: from to
VIN:
from to
Engine: LM2
Transmission: Chevrolet Silverado Suburban Tahoe 2020
2021
2021 LM2 LM2 LM2 GMC
Sierra Yukon models
2020
2021
LM2 LM2 Involved Region or Country Condition Cause North America, Uzbekistan, Russia, Middle East, Israel, Palestine, Chile, Columbia, Ecuador, Paraguay, Peru, Uruguay, Japan, S. Korea, Thailand, Australia, New Zealand.
Customer concern of smoke or exhaust fumes/odor in the cabin or exhaust fumes/odor outside the cabin.
This condition may be caused by an improper weld on the Exhaust Back Pressure Valve. Page 2 November, 2021 Bulletin No.: 21-NA-267 Test for a leaking exhaust backpressure valve weld joint using the Power Smoke diagnostic leak detector (GE-52250 – refer to the latest version of PIP5684).
• Please note, smoke from the tester may not get through the DPF, so test downstream by administering the smoke at the fitting on the tailpipe bladder seal.
Important: Be certain to remove the duct tape from the exhaust cooler after testing.
• Also, the tailpipe bladder seal doesn’t reach the exhaust cooler so use duct tape around the pipe to seal the cooler holes.
Repair this or any other leaks as necessary.
Refer to the pictures below and inspect the weld joint on the Exhaust Back Pressure Valve:
Note: If the weld joint is leaking, replace the Exhaust Back Pressure Valve. Correction 5735432 • The exhaust backpressure valve is located between the downpipe from the SCR w/ filter and the under floor SCR. 5735765 • A leak may be caused by an ineffective weld, allowing for a leak at the flange joint. Bulletin No.: 21-NA-267 November, 2021 Page 3
5735764
• Soapy water can be used to identify the leak, though smoke from the GE-52250 is also effective. Version Modified 1
Released November 19, 2021
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.
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