Strattec Smart Key Fob (FCC ID HYQ1ES) – Specs, Fitments & Programming

By Mohammad H. Abdelhadi, ALOA-Certified Master Locksmith, mobile automotive locksmith. Reviewed by Ray Obar, Master Locksmith. Updated June 1, 2026.

Sourcing decisions for the Strattec Smart Key Fob (FCC ID HYQ1ES) split between OEM and aftermarket paths, and understanding the differences matters for both locksmiths and vehicle owners. An OEM unit from Strattec Security Corporation carries guaranteed compatibility with the onboard receiver module and meets factory radio-frequency specifications, while aftermarket variants of this fob can vary in component quality and antenna tuning. The Strattec Smart Key Fob (FCC ID HYQ1ES) requires key-learning procedures through the vehicle’s body control module regardless of sourcing channel, making proper diagnostic equipment essential. For technicians, every variant of the device must be validated against the target vehicle’s immobilizer protocol before delivery to the customer. When replacing the Strattec Smart Key Fob (FCC ID HYQ1ES), confirm that the transponder chip inside matches the expected specification and that the unit’s operating frequency aligns with the vehicle’s receiver.

Strattec Smart Key Fob (FCC ID HYQ1ES) Technical Specifications

This smart key operates at 315 MHz, a frequency standard across a wide segment of General Motors vehicles produced for the North American market. Inside the fob housing sits an NXP PCF7937E transponder chip, which handles cryptographic challenge-response communication with the vehicle’s immobilizer system. The PCF7937E is a versatile transponder IC from NXP Semiconductors, supporting multiple authentication protocols. In this application, it enables passive keyless entry and push-button start functionality — the vehicle detects the fob’s presence without requiring the driver to physically insert or press anything to unlock doors or start the engine.

The FCC ID HYQ1ES is registered to Strattec Security Corporation, a major supplier of lock and key components to North American automakers. Strattec has a long-standing manufacturing relationship with General Motors, producing ignition lock cylinders, key blanks, and electronic key assemblies. This particular SKU reflects that OEM-tier supply chain positioning, which is why the fob appears as both an original-equipment part and as an aftermarket replacement under the Strattec brand name.

Vehicle Fitments for the HYQ1ES Smart Key

The following vehicles have been validated as compatible with this smart key fob:

• Chevrolet Silverado (2019) — Full-size pickup truck requiring proximity-based keyless entry and push-to-start ignition.
• GMC Acadia (2017–2023) — Mid-size crossover SUV spanning two refresh cycles within the second generation.
• GMC Sierra (2019) — Full-size pickup truck sharing platform architecture with the Silverado.
• GMC Terrain (2018–2024) — Compact crossover SUV with a broad model-year range of compatibility.

The year-range spread across these fitments is notable. The GMC Acadia coverage from 2017 through 2023 and GMC Terrain coverage from 2018 through 2024 indicate that General Motors maintained a consistent immobilizer and keyless-entry architecture across multiple model-year updates for these platforms. Locksmiths servicing these vehicles can stock a single SKU to cover a wide service window, reducing inventory complexity.

Programming and Key Learning Procedures

Adding the Strattec Smart Key Fob (FCC ID HYQ1ES) to a supported vehicle requires a diagnostic scan tool capable of communicating with GM’s body control module (BCM). The procedure typically involves placing the vehicle into a key-learning mode through the scan tool interface, then bringing the fob into proximity range so the BCM can interrogate the PCF7937E transponder and register its unique identifier.

On-board programming — the kind of self-learn procedure where a customer uses two existing working keys to add a third — is generally not available for smart key systems in this generation of GM vehicles. The BCM requires authenticated tool access to modify its key table. This means a qualified automotive locksmith or dealership technician with a compatible diagnostic platform is needed for every programming event, whether adding a new fob to an existing set or performing a full key replacement.

Technicians should verify that the BCM firmware is up to date before attempting key registration. Older firmware revisions on some early model-year vehicles have been known to reject valid transponders until a module update is applied. This is especially relevant for 2017–2018 Acadia and 2018 Terrain units that may have left the factory with earlier software builds.

NXP PCF7937E Transponder Details

The PCF7937E is a multi-application transponder chip manufactured by NXP Semiconductors. It supports several cryptographic protocols and can be configured during manufacturing to operate within different immobilizer ecosystems. In the GM application tied to this fob, the chip communicates with the vehicle’s low-frequency antenna coil embedded in the steering column area and the RF receiver module that handles the 315 MHz remote functions.

For locksmiths, recognizing the PCF7937E is useful when diagnosing no-start conditions or key rejection errors. If a scan tool reads the transponder and returns an unexpected chip identifier, that mismatch can indicate a counterfeit or incorrectly programmed aftermarket unit. Genuine Strattec units and quality aftermarket equivalents will consistently identify as PCF7937E when interrogated.

OEM Versus Aftermarket Considerations

The aftermarket space for GM smart keys with the HYQ1ES designation includes units from multiple third-party manufacturers at various price points. While some aftermarket fobs use the correct NXP PCF7937E chip and function identically to the OEM part, others may substitute alternative transponder ICs that can behave unpredictably during programming or fail prematurely under temperature extremes.

When evaluating an aftermarket unit, locksmiths should check the following before committing to a programming session:

• Confirm the transponder reads as PCF7937E on a diagnostic tool, not a generic or substitute chip ID.
• Verify that the RF output at 315 MHz falls within acceptable power and modulation parameters — weak signal strength causes intermittent lock and unlock failures.
• Inspect the physical housing for proper battery contact alignment and gasket sealing, since water intrusion is a common failure mode for aftermarket fobs with lower build tolerances.

Strattec’s OEM-tier units avoid these concerns but come at a higher wholesale cost. The trade-off between margin and callback risk is a business decision each locksmith shop makes based on their warranty policies and customer expectations.

When Vehicle Owners Should Seek Professional Service

Vehicle owners driving a compatible Chevrolet Silverado, GMC Acadia, GMC Sierra, or GMC Terrain who need a replacement smart key should plan to have the fob programmed by a professional. Purchasing this fob online and expecting it to work without a programming session is a common misconception — the vehicle’s immobilizer will not recognize an unregistered transponder regardless of the unit’s physical compatibility.

An automotive locksmith with GM diagnostic capability can typically complete the programming at a lower cost and with more scheduling flexibility than a dealership service department. Mobile locksmith services are particularly convenient for this type of work, since the programming is performed at the vehicle and does not require a shop lift or any mechanical disassembly.

Related help: Chevrolet auto locksmith, GMC auto locksmith, car key replacement, car key programming.

Compatible and related keys: related key: Strattec Smart Key Fob (FCC ID HYQ1AS).