Sensor, air quality indicator

Years 2025–27 Models 4 Factory citations 17

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Also documented for Buick

Documented applications

CT5 — Alpha 2 (2020–2026)

2025–2026 Factory-verified

Premium Luxury, Sport: O; 2025: V-Series, V-Series Blackwing: O; 2026: V-Series: O; V-Series Blackwing: S

GM factory document — 2025 cadillac ct5 fleet order guide rpo codes, p.1.
GM factory document — 2025 cadillac ct5 v ct5 v blackwing fleet order guide rpo codes, p.1.
GM factory document — 2026 cadillac ct5 fleet order guide rpo codes, p.1.
GM factory document — 2026 cadillac ct5 v ct5 v blackwing fleet order guide rpo codes, p.1.
GM factory document — 2025 cadillac ct5 fleet order guide, p.19.
GM factory document — 2026 cadillac ct5 fleet order guide, p.20.
GM factory document — 2025 cadillac ct5 v ct5 v blackwing fleet order guide, p.24.
GM factory document — 2026 cadillac ct5 v ct5 v blackwing fleet order guide, p.5.

Escalade IQ — Ultium BEV (2025–2027)

2026–2027 Factory-verified

GM factory document — 2026 cadillac all electric escalade iq fleet order guide rpo codes, p.1.
GM factory document — 2027 cadillac all electric escalade iql fleet order guide rpo codes, p.1.

Optiq — BEV3 (2025–2027)

2025–2027 Factory-verified

2025: Luxury 1SE, Sport 1SH: S; Luxury 1SC, Sport 1SF: not available; 2026–2027: Premium Luxury, Premium Sport, V-Series: S; Luxury, Sport: not available

GM factory document — 2025 cadillac all electric optiq fleet order guide rpo codes, p.1.
GM factory document — 2027 cadillac all electric optiq optiq v fleet order guide rpo codes, p.1.
GM factory document — 2025 cadillac all electric optiq fleet order guide, p.7.
GM factory document — 2026 cadillac all electric optiq optiq v fleet order guide, p.5.
GM factory document — 2027 cadillac all electric optiq optiq v fleet order guide, p.6.

Vistiq — BEV3 (2026–2027)

2026–2027 Factory-verified

all trims: S

GM factory document — 2026 cadillac all electric vistiq fleet order guide, p.57.
GM factory document — 2027 cadillac all electric vistiq fleet order guide, p.57.

This page aggregates every documented appearance of USK in the Cadillac reference. Confidence and citations are shown per application — the same code can be better documented in one year than another.