NHTSA ID Number: 10200147
Manufacturer Communication Number: 21NA149
TSB/Document Date: 2021-08-09
Summary
This technical bulletin provides repair information to correct a customer concern of Engine Wire Harness Chafing.
Subject: Engine Wire Harness Chafing
Brand:
Model:
Model
Year:
from
to
VIN:
Engine:
from ot
Silverado 1500 (New Mod2019 2019
el)
Silverado 1500
2020 2021
Sierra 1500 (New Model)
2019 2019
Sierra 1500
2020 2021
Equipped with L82, L84, L87, LV3, L3B, or LM2
Involved
Region United States, Canada, Mexico, Middle East, Chile, Paraguay, Uruguay, Thailand, Australia and New Zealand.
or
Country
Additional
Options
(RPOs)
Some customers may comment on one or more of the following conditions:
• Check Engine light illuminated
• Reduced Engine Power (REP)
Condi• Reduced Power Steering Assist
tion
• Transmission erratically shifting
• No start condition
• Vehicle stalls
5868347
Example of extreme wire chaffing
The cause of the condition may be an engine wire harness clip was removed during production due to ergonomic issues (hand
Cause clearance and branch stiffness). This led to an uncontrolled branch that came into contact with the ECM/TCM bracket, driver side
upper control arm, and/or shock tower and caused chaffing during engine vibration and roll.
Correction
Utilizing Engine Harness sleeves, anti-abrasion tape, and zip-ties to secure the harness away from one or more of the chaffing
points. Follow the Service Procedure steps below.
Service Procedure
1. Lift and support the vehicle. Refer to Lifting and Jacking the Vehicle in SI.
2. Remove driver side tire and wheel and driver wheelhouse liner. Refer to Tire and Wheel Removal and Installation,
and Front Wheelhouse Liner Replacement in SI.
5868341
3. Locate the three contact points where the wire harness is chaffing, the ECM/TCM black bracket (1), the upper control
arm (2), and the shock tower bolt (3).
5868349
4. At the ECM/TCM bracket, locate the wire harness laying against the ledge (1).
5868350
Wrap the wire harness with the shorter Engine Harness Sleeve then utilizing zip ties and two small holes in the
bracket (1).
5868352
Secure the harness snug to the bracket to prevent movement.
5868355
5. At the upper control arm (1), secure the harness away from control arm (example above shows harness in the correct
position, unwrapped).
5868357
Wrap the harness in the shorter Engine Harness Sleeve then wrap with anti-abrasion tape secure it to the harness
clip above the ECM/TCM bracket (1) to keep out of the way of the upper control arm.
5868359
6. At the shock tower point there is a wire harness canal (1).
5868358
5868362
Using the long Engine Harness Sleeve, wrap the harness and secure it snug to the canal using zip-ties.
5868367
7. Verify the wire harness is wrapped and secured at all three points, the ECM/TCM Bracket (1), Upper Control Arm
(2), and the Shock Tower (3). Then reassemble the vehicle.
8. Reinstall the front wheelhouse liner and tire and wheel. Refer to Front Wheelhouse Liner Replacement and Tire and
Wheel Removal and Installation in SI.
9. Remove the support and lower the vehicle.
Parts Information
Causal
Part
Description
Part Number
X
Engine Harness Sleeve
84820678
X
Engine Harness Sleeve
84826758
X
Tie Strap
12337820
Qy
t
Causal
Part
Description
Part Number
X
Black Push Pin Tie
Strap
84396606
Qy
t
Warranty Information
For vehicles repaired under the Bumper-to-Bumper coverage (Canada Base Warranty coverage), use the following labor
operation. Reference the Applicable Warranties section of Investigate Vehicle History (IVH) for coverage information.
Labor Operation
Description
Labor Time
*5486188
Wrap and Secure Engine Wire Harness
1.3 hr
*This is a unique Labor Operation for Bulletin use only.
Version
1
Modified
Released June 29,
2021
- 6X better wear protection on critical engine parts than...
- 1.3X better sludge protection than industry standards*
- 3X Stronger against viscosity breakdown than leading full...
- Protection for 10,000 miles between oil changes
- Meets or exceeds the following specifications: API SP/SN...
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: 21NA149
Replacement Service Bulletin Number:
MFR Communication Date: 2021-06-29
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 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. THINKSCAN 689BT Bidirectional Scan Tool Can Be Used Immediately After It is Turned On, Without Complicated Registration Process, Which is More Convenient & Quick.
- Full Bi-Directional Control & 3000+ Active Tests: Take control and test components like actuators, fuel injectors, relays, and cooling fans in real time. You’ll quickly see if the problem is in the part itself or the control module — saving you hours of guesswork and frustrating trial-and-error.
- Advanced ECU Coding Capabilities: Handle module matching and hidden feature activation with confidence. When you replace an ECU or want to customize settings, this obd2 scanner diagnostic bi directional tool gives you the professional-level capabilities you need without the dealership price tag.
- 34+ Useful Reset and Maintenance Functions: Complete everyday service tasks smoothly with a wide range of helpful reset and maintenance functions. Whether you’re keeping up with regular upkeep or tackling a specific job, this scanner makes maintenance simpler and less stressful for both DIYers and pros.
- Comprehensive Full System Diagnostics: Diagnose every major system — Engine, Transmission, ABS, SRS, TPMS, and more — all in one place. Finally stop wondering if you’re missing something important; get the full picture and clear codes with ease.
- Top Reasons to Choose the D7S OBD2 Scanner: XTOOL D7S car scan tool, an upgrade of XTOOL D7, offers comprehensive features for automotive technicians, workshops, and DIY enthusiasts 1. Upgraded Hardware: 2+64GB memory, rear camera, intuitive interface, foldable bracket 2. Complete Diagnostics: FCA
Autoauth, OE-level all system scan, 39+ maintenance services, 4K+ bidirectional, CANFD/DoIP protocol 3. Advanced Capabilities: ECU c0ding, PMI functions 4. Wide Compatibility: Support 10,000+ models, covering 99% vehicle brands 5. Multi-language: Available in 22+ languages, No IP Restrictions 6. 3-Year Updates: Save 300 bucks on software updates for the latest features and optimizations - 2026 Upgraded D7S Car Scanner Features: The newly 2026 D7S V2.0 scanner for car brings exciting features for advanced vehicle diagnostics and enhanced user experience 1. FCA AutoAuth: Now supports FCA SGW module for Chrysler, for Jeep, for Dodge (2018+), for Fiat (2017+), enabling faster vehicle communication without gateway restrictions 2. PMI (Offline ECU Pr0gramming): Allows for Ford, for Lincoln, and for Mazda ECU pr0gramming for new modules 3. Optimized Diagnostic Report 2.0: Personalized reports with logos and customer info for auto shops. Note: Compatibility varies by cars, please check before order
- 39+ Services/Resets/Adaptations/Relearns/Calibrations: XTOOL D7S full system car scanner diagnostic tool tackles 99% of common car issues through its 36+ special functions, including Oil Reset, EPB, SAS, BMS, Throttle Reset, Injector C0ding, ABS Bleed, TPMS Reset, Power Balance, etc and also covers specific-vehicle functions like Crank Sensor Relearn, ABS Initialization, Cylinder Power Balance, Fuel Trim Reset, Idle Relearn etc. This car diagnostic scanner enhances efficiency, making repairs and maintenance hassle-free. Tip: DO NOT for All vehicles, please check compatibility first
- Cost-effective ECU C0ding Scan Tool for Specific Brands: Enhance your vehicle's performance with XTOOL D7S! This obd2 scanner all systems bidirectional offers advanced capabilities at an affordable price, supports online for BMW, for Benz and offline for BENZ, for MIT, along with PMI functions for Ford, for Mazda, and for Lincoln
. Ideal for technicians and DIY enthusiasts, this automotive scanner diagnostic tool optimizes vehicle performance and enhances the driving experience. Note: Not for all cars and modules, please send car VIN to check the compatibility before purchase - OE All System Diagnostic & 8 Pids Graphing: XTOOL D7S is a comprehensive all system bi directional obd2 scanner that delivers dealer-level diagnostics, completely controlling over your vehicle’s performance and health. This automotive scan tool can read and clear DTCs, view live data and ECU information, retrieve freeze frames, and perform active tests and full obd2 functions. This bi-directional scan tool can can identify your vehicle's make, model, and year information with just one click and show up to 8 PIDs live data with options for CSV viewing, playback, and recording for in-depth analysis. It is easy-to-use for both professionals and beginners, helping pinpoint issues efficiently
- 【✅Compared to BOSSCOMM IF742, IF745 Offers Full-System Diagnostics】The BOSSCOMM IF745 car diagnostic scanner is an upgraded model of IF742. In addition to supporting all OBD2 Code Reader functions and 6 reset options (ABS/EPB/SAS/BMS/Oil/Throttle), it expands diagnostics from 4 systems (Check Engine/ABS/SRS/Transmission) to vehicle All systems, including Steering, Suspension, and Body Electronics. This provides deeper, more comprehensive diagnostic capabilities.
- 【✨10 OBD2 Functions】The BOSSCOMM IF745 scan tool’s DTC Lookup instantly translates fault codes into user-friendly explanations, its I/M Readiness feature streamlines emissions testing with a single tap, and Freeze Frame lets you pinpoint the exact moment of a fault for in-depth root-cause diagnosis. Combined with a live data dashboard and advanced diagnostics (O2S, OBMon, EVAP), it delivers comprehensive insights for confident troubleshooting.
- 【✨Deep Diagnostics for All Vehicle System Modules】Beyond code reading/clearing and ECU information retrieval, our all-in-one data stream feature lets you inspect all current fault codes and their locations across the vehicle’s systems. This vehicle code reader helps you turn off dashboard warning lights and perform a comprehensive self-check of your car at home—no more back-and-forth trips to the repair shop or hefty inspection fees.
- 【✨6 Essential Resets: ABS Bleeding, Oil, EPB, SAS, Throttle, BMS】The BOSSCOMM IF745 obd2 scanner diagnostic tool swiftly purges air from brake lines to restore braking sensitivity, fine-tunes maintenance cycles to eliminate false alerts, resolves parking brake issues with one-click control, recalibrates steering sensors for stability, optimizes engine idling/acceleration for smoother performance, and deeply resets battery systems to extend lifespan and range via precise parameter adjustments.❗NOTE: Does NOT support bidirectional control, coding, or programming.
- 【✨10,000+ Car Models, AutoVIN, 13 Languages】The BOSSCOMM IF745 vehicle scanner diagnostic tool covers 73+ global car brands and offers support in 13 languages, making it perfect for DIYers, auto mechanics, or as a thoughtful gift. With a single-click AutoVIN feature, it instantly retrieves vehicle serial numbers, streamlining diagnostics for users globally. This adaptable tool balances user-friendliness with precision, catering to both personal and professional requirements.✅Unsure about compatibility? Compatibility will vary on vehicles' model and year, pls reach us via 📧 [email protected] 📧 before purchase.
This product presentation was made with AAWP plugin.