Strattec Smart Key Fob (FCC ID HYQ2AB) – Cadillac Key Guide

Used across several Cadillac platforms including the ATS, CTS, Escalade, SRX, and XTS, the Strattec Smart Key Fob (FCC ID HYQ4AA) – HU100, PCF7952E, 31 (FCC ID HYQ2AB) serves as the primary proximity-based entry and ignition device for these vehicles. Each Strattec Smart Key Fob (FCC ID HYQ2AB) integrates an NXP PCF7937E transponder chip for encrypted immobilizer communication, operating at a 315 MHz RF frequency for remote keyless entry functions. For automotive locksmiths, this unit presents specific programming requirements tied to General Motors security protocols. Owners who need to replace the fob will typically work through a dealership or qualified locksmith equipped with the necessary diagnostic hardware. A properly enrolled Strattec Smart Key Fob (FCC ID HYQ2AB) enables push-button start, passive keyless entry, and remote lock/unlock — all core smart key features expected on this generation of Cadillac vehicles.

Technical Specifications of the Strattec Smart Key Fob (FCC ID HYQ2AB)

The device is manufactured by Strattec Security Corporation, a major OEM supplier of lock and key components to the North American automotive industry. Strattec has long served as a Tier 1 supplier for General Motors, and this particular smart key is part of that manufacturing relationship.

At the heart of the fob sits an NXP PCF7937E transponder chip. The PCF7937E belongs to NXP’s family of automotive crypto transponders and handles the challenge-response authentication sequence between the key and the vehicle’s immobilizer module. Without successful transponder authentication, the engine control module will not authorize ignition — even if the fob’s RF signal successfully unlocks the doors.

The remote keyless entry portion of this smart key operates at 315 MHz, which is the standard frequency band allocated for automotive RKE systems in the North American market. The FCC registration under ID HYQ2AB confirms compliance with Part 15 regulations for this frequency.

Cadillac Vehicle Compatibility

Based on validated fitment data, this fob covers the following Cadillac models and year ranges:

• Cadillac ATS — 2012 through 2019
• Cadillac CTS — 2014 through 2019
• Cadillac Escalade — 2015 through 2020
• Cadillac SRX — 2010 through 2016
• Cadillac XTS — 2013 through 2019

These models span a significant portion of Cadillac’s recent lineup, from the compact ATS sedan to the full-size Escalade SUV. Across all five platforms, the vehicle’s Body Control Module (BCM) and Engine Control Module (ECM) expect the PCF7937E transponder signature during start authorization, making chip compatibility a non-negotiable factor when sourcing a replacement.

Programming Considerations for Locksmiths

Enrolling the Strattec Smart Key Fob (FCC ID HYQ2AB) to a Cadillac equipped with push-button start requires a professional-grade diagnostic tool capable of communicating with the GM security system. The programming procedure typically involves two distinct phases: transponder registration with the immobilizer (handled through the ECM or BCM depending on architecture), and RF remote pairing for the keyless entry functions.

Technicians should be aware that GM vehicles from this era use varying security generations. Depending on model year and trim, the target vehicle may run an older PK3+ system or a newer generation that requires online authentication through GM’s SPS (Service Programming System). The latter scenario requires internet connectivity during the programming session and valid access credentials — a consideration that directly affects job time and quoting.

When performing a key add procedure (programming an additional fob while at least one working key is available), the process is generally more straightforward than an all keys lost situation. With a working key present, most professional tools can complete the enrollment locally without online authorization, though this varies by specific platform and year.

For all keys lost scenarios on these Cadillac models, the locksmith will need to perform an IMMO reset or seed/pin extraction depending on tool capabilities. Some platforms in this fitment range store security data in the ECM, while others distribute it across modules. Confirming the exact security architecture before beginning work prevents wasted time and potential module lockouts.

OEM vs. Aftermarket Considerations

As an OEM-grade product from Strattec Security Corporation, this smart key meets the original equipment specification for the listed Cadillac models. Aftermarket alternatives with the same FCC ID may be available at lower price points, but build quality and transponder reliability can vary. Locksmiths who stock this item frequently report that genuine Strattec units program more reliably and tend to exhibit fewer post-installation warranty claims compared to off-brand equivalents.

Vehicle owners comparing options should understand that regardless of whether the fob shell is OEM or aftermarket, the PCF7937E transponder chip inside must be a genuine NXP component for the immobilizer to accept it. Some low-cost aftermarket fobs use cloned or incompatible chips that may pair initially but fail intermittently under real-world conditions — an especially frustrating outcome given the cost of professional programming.

When to Contact a Locksmith

Replacement of this smart key is not a DIY-friendly task. Unlike older transponder keys that could sometimes be self-programmed through an on-board procedure, Cadillac smart keys from this generation require diagnostic tool access to complete enrollment. A qualified automotive locksmith with GM programming capability can typically complete the job on-site, saving the vehicle owner the cost and inconvenience of a dealership visit and tow.

Common scenarios that call for a replacement include a damaged or water-logged fob, a key that has stopped communicating with the vehicle after a battery change (indicating possible chip failure), or simply needing a spare. Regardless of the reason, ensuring the replacement unit carries the correct FCC ID — HYQ2AB — and houses a compatible PCF7937E transponder is essential before any programming attempt begins.