FMVSS 401: Interior Trunk Release explained.

What FMVSS 401 says it is for

The eCFR heads this section "Standard No. 401; Interior trunk release." Under 49 CFR part 571, the Federal Motor Vehicle Safety Standards are the numbered standards that set safety performance requirements for motor vehicles and equipment. The text below is quoted from 571.401 as current through October 29, 2026.

This standard establishes the requirement for providing a trunk release mechanism that makes it possible for a person trapped inside the trunk compartment of a passenger car to escape from the compartment.

What it applies to

The application section of the standard says:

This standard applies to passenger cars that have a trunk compartment. This standard does not apply to passenger cars with a back door.

Applicability is decided by the text of the standard as written, including any exclusions it lists, and by the date-specific rules in it. This page does not decide whether a particular vehicle or item is covered.

How the standard is organized

The eCFR text of 571.401 has these top-level sections:

• S1: Purpose and scope
• S2: Application
• S3: Definitions
• S4: Requirements

In all, the text has 4 numbered headings. Use the finder above to search them; for example, a search for "test" lists the headings that mention tests.

Key requirements, quoted from the text

These are excerpts from the requirements sections of 571.401, in the order the standard presents them. Long paragraphs are shortened where marked with [...]; the eCFR has the complete text, tables and figures, which this page omits.

S4 Requirements. S4.1 Each passenger car with a trunk compartment must have an automatic or manual release mechanism inside the trunk compartment that unlatches the trunk lid. Each trunk release shall conform, at the manufacturer's option, to either S4.2(a) and S4.3, or S4.2(b) and S4.3. The manufacturer shall select the option by the time it certifies the vehicle and may not thereafter select a different option for the vehicle. S4.2(a) Each manual release mechanism installed pursuant to S4.1 of this standard must include a feature, like lighting or phosphorescence, that allows the release mechanism to be easily seen inside the closed trunk compartment. (b) Each automatic release mechanism installed pursuant to S4.1 of this section must unlatch the trunk lid within 5 minutes of when the trunk lid is closed with a person inside the trunk compartment. S4.3(a) Except as provided in paragraph S4.3(b), actuation of the release mechanism required by S4.1 of this standard must completely release the trunk lid from all latching positions of the trunk lid latch. [...]

Defined terms

The standard defines 2 terms in its definitions section; the first 2 are quoted here from the eCFR.

• Back door means a door or door system on the back end of a passenger car through which cargo can be loaded or unloaded. The term includes the hinged back door on a hatchback or a station wagon.
• Trunk lid means a moveable body panel that is not designed or intended as a passenger car entry point for passengers and that provides access from outside a passenger car to a trunk compartment. The term does not include a back door or the lid of a storage compartment located inside the passenger compartment of a passenger car.

Limits of this page

This page quotes the text of 49 CFR 571.401 as published in the eCFR, current through October 29, 2026. It omits tables, figures, cross-referenced test procedures in other parts, and the preambles and rulemaking history that explain the rule. It does not tell you whether a given vehicle, part or product complies, how to run a test, or what a manufacturer must certify. Compliance questions go to the manufacturer's engineers, qualified counsel or NHTSA. The eCFR is an editorial compilation, not the official legal edition of the Federal Register.

Sources

Sources opened and read November 2, 2026.

• eCFR: 49 CFR 571.401, Standard No. 401; Interior trunk release. (current through October 29, 2026) (read November 2, 2026)
• eCFR: 49 CFR part 571, Federal Motor Vehicle Safety Standards (current through October 29, 2026) (read November 2, 2026)