Wiring provisions, horn/siren circuit

Years 1999, 2001–09, 2014, 2016–17, 2025–27 Models 12 Factory citations 36

Also described as Wiring, horn and siren circuit (SEO)Wiring, horn and siren circuit, inline for customer-furnished switchWiring provisions, horn and siren circuitWiring, horn and siren circuit

Also documented for Cadillac GMC

Documented applications

Avalanche — GMT900 (2007–2013)

2007–2009 Factory-verified

GM factory document — 2007 chevrolet avalanche 2wd rpo code list, p.1.
GM factory document — 2008 chevrolet avalanche 2wd rpo code list, p.1.
GM factory document — 2009 chevrolet avalanche 2wd rpo code list, p.1.

Blazer EV (2024–2027)

2025–2027 Factory-verified

only in: Police Package

GM factory document — 2025 chevrolet blazer ev police package fleet order guide rpo codes, p.1.
GM factory document — 2026 chevrolet blazer ev police package fleet order guide rpo codes, p.1.
GM factory document — 2027 chevrolet blazer ev police package fleet order guide rpo codes, p.1.

Caprice — Caprice PPV (2011–2017)

2017 Factory-verified

A

GM factory document — 2017 chevrolet caprice ppv order guide copy gm authority, p.5, p.11.

Impala — eighth generation (2000–2005)

2001–2005 Factory-verified

GM factory document — 2001 chevrolet impala rpo code list, p.1.
GM factory document — 2002 chevrolet impala rpo code list, p.1.
GM factory document — 2003 chevrolet impala rpo code list, p.1.
GM factory document — 2004 chevrolet impala rpo code list, p.1.
GM factory document — 2005 chevrolet impala rpo code list, p.1.
GM Heritage factory kit — 2001 Chevrolet Impala, p.35.
GM Heritage factory kit — 2005 Chevrolet Impala, p.26.

Impala — ninth generation (2006–2016)

2006–2009 Factory-verified

GM factory document — 2006 chevrolet impala rpo code list, p.1.
GM factory document — 2007 chevrolet impala rpo code list, p.1.
GM factory document — 2008 chevrolet impala rpo code list, p.1.
GM factory document — 2009 chevrolet impala rpo code list, p.1.

Lumina — second generation (1995–2001)

1999 Factory-verified

Special equipment option.

GM factory document — 1999 chevrolet lumina rpo code list, p.1.

Silverado 1500 — Fifth generation (2027)

2027 Factory-verified

GM factory document — 2027 chevrolet next generation silverado 1500 retail and fleet fleet order guide rpo codes, p.1.

Silverado — T1XX (2019–2026)

2025–2026 Factory-verified

GM factory document — 2025 chevrolet silverado 1500 retail and fleet fleet order guide rpo codes, p.1.
GM factory document — 2026 chevrolet silverado 1500 retail and fleet fleet order guide rpo codes, p.1.

Suburban — GMT900 (2007–2014)

2007–2009 Factory-verified

GM factory document — 2007 chevrolet chevy suburban 2wd rpo code list, p.1.
GM factory document — 2008 chevrolet chevy suburban 2wd rpo code list, p.1.
GM factory document — 2009 chevrolet chevy suburban 2wd rpo code list, p.1.

Tahoe — GMT900 (2007–2014)

2007–2009, 2014 Factory-verified

Trim marks in the 2014 guides: Police: O; Special Service: O.

GM factory document — 2007 chevrolet tahoe 2wd rpo code list, p.1.
GM factory document — 2008 chevrolet tahoe 2wd rpo code list, p.1.
GM factory document — 2009 chevrolet tahoe 2wd rpo code list, p.1.
GM factory document — 2014 chevrolet tahoe police vehicle fleet order guide wayback, p.2.
GM factory document — 2014 chevrolet tahoe special service vehicle fleet order guide wayback, p.2.
GM Heritage factory kit — 2007 Chevrolet Tahoe, p.31, p.181.

Tahoe — K2XX (2015–2020)

2016 Factory-verified

2016: Police Vehicle, Special Service: A

GM factory document — 2016 chevrolet tahoe police vehicle fleet order guide wayback, p.2.
GM factory document — 2016 chevrolet tahoe special service vehicle fleet order guide wayback, p.2.

Tahoe — T1XX (2021–2027)

2025–2027 Factory-verified

2027: police guides: O on both columns; only in: Police Package and Special Service models

GM factory document — 2025 chevrolet new tahoe police package and special service fleet order guide, p.10.
GM factory document — 2026 chevrolet tahoe police package and special service fleet order guide, p.10.
GM factory document — 2027 chevrolet tahoe police package and special service fleet order guide, p.10.

This page aggregates every documented appearance of 6J4 in the Chevrolet reference. Confidence and citations are shown per application — the same code can be better documented in one year than another.