TSB: BUICK 3500, 4500HD, 4500XD, 5500HD, ACADIA, BLAZER, BOLT EV, CAMARO, CANYON, COLORADO, CORVETTE, CT4, CT5, CT6, ENCLAVE, ENCORE, ENCORE GX, ENVISION, EQUINOX, ESCALADE, ESCALADE ESV, EXPRESS, IMPALA, MALIBU, REGAL, SAVANA, SIERRA 1500, SIERRA 2500, SILVERADO 1500, SILVERADO 2500, SILVERADO 3500, SILVERADO 4500HD, SONIC, SPARK, SUBURBAN, TAHOE, TERRAIN, TRAILBLAZER, TRAVERSE, TRAX, XT4, XT5, XT6, YUKON, YUKON XL (2020–2021)

Bulletin 21NA061 — March 22, 2021

Bulletin Details

Bulletin ID21NA061
ManufacturerBUICK
Models3500, 4500HD, 4500XD, 5500HD, ACADIA, BLAZER, BOLT EV, CAMARO, CANYON, COLORADO, CORVETTE, CT4, CT5, CT6, ENCLAVE, ENCORE, ENCORE GX, ENVISION, EQUINOX, ESCALADE, ESCALADE ESV, EXPRESS, IMPALA, MALIBU, REGAL, SAVANA, SIERRA 1500, SIERRA 2500, SILVERADO 1500, SILVERADO 2500, SILVERADO 3500, SILVERADO 4500HD, SONIC, SPARK, SUBURBAN, TAHOE, TERRAIN, TRAILBLAZER, TRAVERSE, TRAX, XT4, XT5, XT6, YUKON, YUKON XL
Model Years2020–2021
Date IssuedMarch 22, 2021
Date Added to NHTSAMay 10, 2021
ComponentELECTRICAL SYSTEM:IGNITION:ANTI-THEFT:IMMOBILIZER/PROXIMITY:KEY/SENDER
Vehicles Affected80 combinations

What is a TSB?

A Technical Service Bulletin is a document issued by the vehicle manufacturer to inform dealership technicians about a known issue and the recommended repair procedure. TSBs are not mandatory recalls — they serve as repair guidance for common problems.

If your vehicle has this issue, bring this bulletin ID to your dealer. If under warranty, the repair should be covered at no cost.

Summary

This service bulletin provides information for dealers on Using EL-52545 When Diagnosing PEPs Transmitter Key Fobs (North America ONLY).

Affected Vehicles

MakeModelYearComponent
CHEVROLET 4500XD 2021 116340 ELECTRICAL SYSTEM:IGNITION:ANTI-THEFT:IMMOBILIZER/PROXIMITY:KEY/SENDER
GMC ACADIA 2021 116340 ELECTRICAL SYSTEM:IGNITION:ANTI-THEFT:IMMOBILIZER/PROXIMITY:KEY/SENDER
CHEVROLET BLAZER 2021 116340 ELECTRICAL SYSTEM:IGNITION:ANTI-THEFT:IMMOBILIZER/PROXIMITY:KEY/SENDER
CHEVROLET BOLT EV 2021 116340 ELECTRICAL SYSTEM:IGNITION:ANTI-THEFT:IMMOBILIZER/PROXIMITY:KEY/SENDER
CHEVROLET CAMARO 2021 116340 ELECTRICAL SYSTEM:IGNITION:ANTI-THEFT:IMMOBILIZER/PROXIMITY:KEY/SENDER
GMC CANYON 2021 116340 ELECTRICAL SYSTEM:IGNITION:ANTI-THEFT:IMMOBILIZER/PROXIMITY:KEY/SENDER
CHEVROLET COLORADO 2021 116340 ELECTRICAL SYSTEM:IGNITION:ANTI-THEFT:IMMOBILIZER/PROXIMITY:KEY/SENDER
CHEVROLET CORVETTE 2021 116340 ELECTRICAL SYSTEM:IGNITION:ANTI-THEFT:IMMOBILIZER/PROXIMITY:KEY/SENDER
CADILLAC CT4 2021 116340 ELECTRICAL SYSTEM:IGNITION:ANTI-THEFT:IMMOBILIZER/PROXIMITY:KEY/SENDER
CADILLAC CT5 2021 116340 ELECTRICAL SYSTEM:IGNITION:ANTI-THEFT:IMMOBILIZER/PROXIMITY:KEY/SENDER
BUICK ENCLAVE 2021 116340 ELECTRICAL SYSTEM:IGNITION:ANTI-THEFT:IMMOBILIZER/PROXIMITY:KEY/SENDER
BUICK ENCORE 2021 116340 ELECTRICAL SYSTEM:IGNITION:ANTI-THEFT:IMMOBILIZER/PROXIMITY:KEY/SENDER
BUICK ENCORE GX 2021 116340 ELECTRICAL SYSTEM:IGNITION:ANTI-THEFT:IMMOBILIZER/PROXIMITY:KEY/SENDER
BUICK ENVISION 2021 116340 ELECTRICAL SYSTEM:IGNITION:ANTI-THEFT:IMMOBILIZER/PROXIMITY:KEY/SENDER
CHEVROLET EQUINOX 2021 116340 ELECTRICAL SYSTEM:IGNITION:ANTI-THEFT:IMMOBILIZER/PROXIMITY:KEY/SENDER
CADILLAC ESCALADE 2021 116340 ELECTRICAL SYSTEM:IGNITION:ANTI-THEFT:IMMOBILIZER/PROXIMITY:KEY/SENDER
CADILLAC ESCALADE ESV 2021 116340 ELECTRICAL SYSTEM:IGNITION:ANTI-THEFT:IMMOBILIZER/PROXIMITY:KEY/SENDER
CHEVROLET EXPRESS 2021 116340 ELECTRICAL SYSTEM:IGNITION:ANTI-THEFT:IMMOBILIZER/PROXIMITY:KEY/SENDER
CHEVROLET MALIBU 2021 116340 ELECTRICAL SYSTEM:IGNITION:ANTI-THEFT:IMMOBILIZER/PROXIMITY:KEY/SENDER
GMC SAVANA 2021 116340 ELECTRICAL SYSTEM:IGNITION:ANTI-THEFT:IMMOBILIZER/PROXIMITY:KEY/SENDER
GMC SIERRA 1500 2021 116340 ELECTRICAL SYSTEM:IGNITION:ANTI-THEFT:IMMOBILIZER/PROXIMITY:KEY/SENDER
GMC SIERRA 2500 2021 116340 ELECTRICAL SYSTEM:IGNITION:ANTI-THEFT:IMMOBILIZER/PROXIMITY:KEY/SENDER
CHEVROLET SILVERADO 1500 2021 116340 ELECTRICAL SYSTEM:IGNITION:ANTI-THEFT:IMMOBILIZER/PROXIMITY:KEY/SENDER
CHEVROLET SILVERADO 2500 2021 116340 ELECTRICAL SYSTEM:IGNITION:ANTI-THEFT:IMMOBILIZER/PROXIMITY:KEY/SENDER
CHEVROLET SILVERADO 3500 2021 116340 ELECTRICAL SYSTEM:IGNITION:ANTI-THEFT:IMMOBILIZER/PROXIMITY:KEY/SENDER
CHEVROLET SPARK 2021 116340 ELECTRICAL SYSTEM:IGNITION:ANTI-THEFT:IMMOBILIZER/PROXIMITY:KEY/SENDER
CHEVROLET SUBURBAN 2021 116340 ELECTRICAL SYSTEM:IGNITION:ANTI-THEFT:IMMOBILIZER/PROXIMITY:KEY/SENDER
CHEVROLET TAHOE 2021 116340 ELECTRICAL SYSTEM:IGNITION:ANTI-THEFT:IMMOBILIZER/PROXIMITY:KEY/SENDER
GMC TERRAIN 2021 116340 ELECTRICAL SYSTEM:IGNITION:ANTI-THEFT:IMMOBILIZER/PROXIMITY:KEY/SENDER
CHEVROLET TRAILBLAZER 2021 116340 ELECTRICAL SYSTEM:IGNITION:ANTI-THEFT:IMMOBILIZER/PROXIMITY:KEY/SENDER
CHEVROLET TRAVERSE 2021 116340 ELECTRICAL SYSTEM:IGNITION:ANTI-THEFT:IMMOBILIZER/PROXIMITY:KEY/SENDER
CHEVROLET TRAX 2021 116340 ELECTRICAL SYSTEM:IGNITION:ANTI-THEFT:IMMOBILIZER/PROXIMITY:KEY/SENDER
CADILLAC XT4 2021 116340 ELECTRICAL SYSTEM:IGNITION:ANTI-THEFT:IMMOBILIZER/PROXIMITY:KEY/SENDER
CADILLAC XT5 2021 116340 ELECTRICAL SYSTEM:IGNITION:ANTI-THEFT:IMMOBILIZER/PROXIMITY:KEY/SENDER
CADILLAC XT6 2021 116340 ELECTRICAL SYSTEM:IGNITION:ANTI-THEFT:IMMOBILIZER/PROXIMITY:KEY/SENDER
GMC YUKON 2021 116340 ELECTRICAL SYSTEM:IGNITION:ANTI-THEFT:IMMOBILIZER/PROXIMITY:KEY/SENDER
GMC YUKON XL 2021 116340 ELECTRICAL SYSTEM:IGNITION:ANTI-THEFT:IMMOBILIZER/PROXIMITY:KEY/SENDER
CHEVROLET 3500 2020 116340 ELECTRICAL SYSTEM:IGNITION:ANTI-THEFT:IMMOBILIZER/PROXIMITY:KEY/SENDER
CHEVROLET 4500HD 2020 116340 ELECTRICAL SYSTEM:IGNITION:ANTI-THEFT:IMMOBILIZER/PROXIMITY:KEY/SENDER
CHEVROLET 5500HD 2020 116340 ELECTRICAL SYSTEM:IGNITION:ANTI-THEFT:IMMOBILIZER/PROXIMITY:KEY/SENDER
GMC ACADIA 2020 116340 ELECTRICAL SYSTEM:IGNITION:ANTI-THEFT:IMMOBILIZER/PROXIMITY:KEY/SENDER
CHEVROLET BLAZER 2020 116340 ELECTRICAL SYSTEM:IGNITION:ANTI-THEFT:IMMOBILIZER/PROXIMITY:KEY/SENDER
CHEVROLET BOLT EV 2020 116340 ELECTRICAL SYSTEM:IGNITION:ANTI-THEFT:IMMOBILIZER/PROXIMITY:KEY/SENDER
CHEVROLET CAMARO 2020 116340 ELECTRICAL SYSTEM:IGNITION:ANTI-THEFT:IMMOBILIZER/PROXIMITY:KEY/SENDER
GMC CANYON 2020 116340 ELECTRICAL SYSTEM:IGNITION:ANTI-THEFT:IMMOBILIZER/PROXIMITY:KEY/SENDER
CHEVROLET COLORADO 2020 116340 ELECTRICAL SYSTEM:IGNITION:ANTI-THEFT:IMMOBILIZER/PROXIMITY:KEY/SENDER
CHEVROLET CORVETTE 2020 116340 ELECTRICAL SYSTEM:IGNITION:ANTI-THEFT:IMMOBILIZER/PROXIMITY:KEY/SENDER
CADILLAC CT4 2020 116340 ELECTRICAL SYSTEM:IGNITION:ANTI-THEFT:IMMOBILIZER/PROXIMITY:KEY/SENDER
CADILLAC CT5 2020 116340 ELECTRICAL SYSTEM:IGNITION:ANTI-THEFT:IMMOBILIZER/PROXIMITY:KEY/SENDER
CADILLAC CT6 2020 116340 ELECTRICAL SYSTEM:IGNITION:ANTI-THEFT:IMMOBILIZER/PROXIMITY:KEY/SENDER
BUICK ENCLAVE 2020 116340 ELECTRICAL SYSTEM:IGNITION:ANTI-THEFT:IMMOBILIZER/PROXIMITY:KEY/SENDER
BUICK ENCORE 2020 116340 ELECTRICAL SYSTEM:IGNITION:ANTI-THEFT:IMMOBILIZER/PROXIMITY:KEY/SENDER
BUICK ENCORE GX 2020 116340 ELECTRICAL SYSTEM:IGNITION:ANTI-THEFT:IMMOBILIZER/PROXIMITY:KEY/SENDER
BUICK ENVISION 2020 116340 ELECTRICAL SYSTEM:IGNITION:ANTI-THEFT:IMMOBILIZER/PROXIMITY:KEY/SENDER
CHEVROLET EQUINOX 2020 116340 ELECTRICAL SYSTEM:IGNITION:ANTI-THEFT:IMMOBILIZER/PROXIMITY:KEY/SENDER
CADILLAC ESCALADE 2020 116340 ELECTRICAL SYSTEM:IGNITION:ANTI-THEFT:IMMOBILIZER/PROXIMITY:KEY/SENDER
CADILLAC ESCALADE ESV 2020 116340 ELECTRICAL SYSTEM:IGNITION:ANTI-THEFT:IMMOBILIZER/PROXIMITY:KEY/SENDER
CHEVROLET EXPRESS 2020 116340 ELECTRICAL SYSTEM:IGNITION:ANTI-THEFT:IMMOBILIZER/PROXIMITY:KEY/SENDER
CHEVROLET IMPALA 2020 116340 ELECTRICAL SYSTEM:IGNITION:ANTI-THEFT:IMMOBILIZER/PROXIMITY:KEY/SENDER
CHEVROLET MALIBU 2020 116340 ELECTRICAL SYSTEM:IGNITION:ANTI-THEFT:IMMOBILIZER/PROXIMITY:KEY/SENDER
BUICK REGAL 2020 116340 ELECTRICAL SYSTEM:IGNITION:ANTI-THEFT:IMMOBILIZER/PROXIMITY:KEY/SENDER
GMC SAVANA 2020 116340 ELECTRICAL SYSTEM:IGNITION:ANTI-THEFT:IMMOBILIZER/PROXIMITY:KEY/SENDER
GMC SIERRA 1500 2020 116340 ELECTRICAL SYSTEM:IGNITION:ANTI-THEFT:IMMOBILIZER/PROXIMITY:KEY/SENDER
GMC SIERRA 2500 2020 116340 ELECTRICAL SYSTEM:IGNITION:ANTI-THEFT:IMMOBILIZER/PROXIMITY:KEY/SENDER
CHEVROLET SILVERADO 1500 2020 116340 ELECTRICAL SYSTEM:IGNITION:ANTI-THEFT:IMMOBILIZER/PROXIMITY:KEY/SENDER
CHEVROLET SILVERADO 2500 2020 116340 ELECTRICAL SYSTEM:IGNITION:ANTI-THEFT:IMMOBILIZER/PROXIMITY:KEY/SENDER
CHEVROLET SILVERADO 4500HD 2020 116340 ELECTRICAL SYSTEM:IGNITION:ANTI-THEFT:IMMOBILIZER/PROXIMITY:KEY/SENDER
CHEVROLET SONIC 2020 116340 ELECTRICAL SYSTEM:IGNITION:ANTI-THEFT:IMMOBILIZER/PROXIMITY:KEY/SENDER
CHEVROLET SPARK 2020 116340 ELECTRICAL SYSTEM:IGNITION:ANTI-THEFT:IMMOBILIZER/PROXIMITY:KEY/SENDER
CHEVROLET SUBURBAN 2020 116340 ELECTRICAL SYSTEM:IGNITION:ANTI-THEFT:IMMOBILIZER/PROXIMITY:KEY/SENDER
CHEVROLET TAHOE 2020 116340 ELECTRICAL SYSTEM:IGNITION:ANTI-THEFT:IMMOBILIZER/PROXIMITY:KEY/SENDER
GMC TERRAIN 2020 116340 ELECTRICAL SYSTEM:IGNITION:ANTI-THEFT:IMMOBILIZER/PROXIMITY:KEY/SENDER
CHEVROLET TRAILBLAZER 2020 116340 ELECTRICAL SYSTEM:IGNITION:ANTI-THEFT:IMMOBILIZER/PROXIMITY:KEY/SENDER
CHEVROLET TRAVERSE 2020 116340 ELECTRICAL SYSTEM:IGNITION:ANTI-THEFT:IMMOBILIZER/PROXIMITY:KEY/SENDER
CHEVROLET TRAX 2020 116340 ELECTRICAL SYSTEM:IGNITION:ANTI-THEFT:IMMOBILIZER/PROXIMITY:KEY/SENDER
CADILLAC XT4 2020 116340 ELECTRICAL SYSTEM:IGNITION:ANTI-THEFT:IMMOBILIZER/PROXIMITY:KEY/SENDER
CADILLAC XT5 2020 116340 ELECTRICAL SYSTEM:IGNITION:ANTI-THEFT:IMMOBILIZER/PROXIMITY:KEY/SENDER
CADILLAC XT6 2020 116340 ELECTRICAL SYSTEM:IGNITION:ANTI-THEFT:IMMOBILIZER/PROXIMITY:KEY/SENDER
GMC YUKON 2020 116340 ELECTRICAL SYSTEM:IGNITION:ANTI-THEFT:IMMOBILIZER/PROXIMITY:KEY/SENDER
GMC YUKON XL 2020 116340 ELECTRICAL SYSTEM:IGNITION:ANTI-THEFT:IMMOBILIZER/PROXIMITY:KEY/SENDER

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What Should You Do?

If your vehicle is affected by this TSB, contact your authorized BUICK dealer. Bring this bulletin ID (21NA061) when you visit. If under warranty, the repair should be free. If your warranty has expired, ask about goodwill coverage — manufacturers sometimes cover TSB-related repairs beyond the warranty period.

Frequently Asked Questions

A recall is a mandatory safety fix — the manufacturer must repair every affected vehicle for free. A TSB is an advisory document that describes a known issue and the recommended fix, but repairs are not required. However, some TSBs eventually lead to recalls if the issue poses a safety risk. TSBs are generally issued for quality or performance problems, while recalls address safety defects.

If your vehicle is still under the manufacturer's warranty, TSB-related repairs are typically covered at no cost. If your warranty has expired, you can ask the dealer about goodwill or customer assistance programs. Many manufacturers will cover or partially cover repairs for well-known issues, especially if the TSB was issued recently or affects a large number of vehicles.

Check the make, model, and model year listed above against your vehicle. If they match, this bulletin likely applies. However, TSBs may only affect vehicles with specific production dates, VIN ranges, or configurations. Your dealer can confirm by entering your VIN into their service system, which will show all applicable TSBs and recalls.

This data comes from the National Highway Traffic Safety Administration (NHTSA). Manufacturers are required to submit copies of all communications (including TSBs) sent to their dealers to NHTSA. The agency makes this data publicly available as part of its vehicle safety monitoring program.