---
kind: "section"
citation: "40 C.F.R. § 1037.621"
title: "40"
number: "1037.621"
heading: "Delegated assembly."
url: "https://uscodex.org/cfr/40/1037.621"
---

# §1037.621. Delegated assembly.

- (a) This section describes provisions that allow certificate holders to sell or ship vehicles that are missing certain emission-related components if those components will be installed by a secondary vehicle manufacturer. [Paragraph (g)](#g) of this section similarly describes how dealers and distributors may modify new vehicles with your advance approval. (Note: See [§ 1037.622](/cfr/40/1037.622.md) for provisions related to manufacturers introducing into U.S. commerce partially complete vehicles for which a secondary vehicle manufacturer holds the certificate of conformity.)
- (b) You do not need an exemption to ship a vehicle that does not include installation or assembly of certain emission-related components if those components are shipped along with the vehicle. For example, you may generally ship fuel tanks and aerodynamic devices along with vehicles rather than installing them on the vehicle before shipment. We may require you to describe how you plan to use this provision.
- (c) You may ask us at the time of certification for an exemption to allow you to ship your vehicles without emission-related components. If we allow this, you must provide emission-related installation instructions as specified in [§ 1037.130](/cfr/40/1037.130.md). You must follow delegated-assembly requirements in [40 CFR 1068.261](/cfr/40/1068.261.md) if you rely on secondary vehicle manufacturers to install certain technologies or components as specified in [paragraph (d)](#d) of this section. For other technologies or components, we may specify conditions that we determine are needed to ensure that shipping the vehicle without such components will not result in the vehicle being operated outside of its certified configuration; this may include a requirement to comply with the delegated-assembly provisions in [paragraph (d)](#d) of this section. We may consider your past performance when we specify the conditions that apply.
- (d) Delegated-assembly provisions apply as specified in this [paragraph (d)](#d) if the certifying vehicle manufacturer relies on a secondary vehicle manufacturer to procure and install auxiliary power units, aerodynamic devices, hybrid components (for powertrain or power take-off), or natural gas fuel tanks. These provisions do not apply for other systems or components, such as air conditioning lines and fittings, except as specified in [paragraph (c)](#c) of this section. Apply the provisions of [40 CFR 1068.261](/cfr/40/1068.261.md), with the following exceptions and clarifications:
  - (1) **Understand references to “engines” to refer to vehicles.**
  - (2) Understand references to “aftertreatment components” to refer to any relevant emission-related components under this [paragraph (d)](#d).
  - (3) **Understand “equipment manufacturers” to be secondary vehicle manufacturers.**
  - (4) The provisions of 40 CFR [1068.261(b)](/cfr/40/1068.261.md?p=b), [(c)(7)](/cfr/40/1068.261.md?p=c-7), [(d)](/cfr/40/1068.261.md?p=c-d), and [(e)](/cfr/40/1068.261.md?p=c-e) do not apply. Accordingly, the provisions of [40 CFR 1068.261(c)](/cfr/40/1068.261.md?p=c) apply regardless of pricing arrangements.
- (e) Secondary vehicle manufacturers must follow the engine manufacturer's emission-related installation instructions. Not meeting the manufacturer's emission-related installation instructions is a violation of one or more of the prohibitions of [§ 1068.101](/cfr/40/1068.101.md). We may also require secondary vehicle manufacturers to recall defective vehicles under [40 CFR 1068.505](/cfr/40/1068.505.md) if we determine that their manufacturing practices caused vehicles to not conform to the regulations. Secondary vehicle manufacturers may be required to meet additional requirements if the certifying vehicle manufacturer delegates final assembly of emission controls as described in [paragraph (d)](#d) of this section.
- (f) Except as allowed by [§ 1037.622](/cfr/40/1037.622.md), the provisions of this section apply to manufacturers for glider kits they produce. Note that under [§ 1037.620](/cfr/40/1037.620.md), glider kit manufacturers are generally presumed to be responsible (in whole or in part) for compliance with respect to vehicles produced from their glider kits, even if a secondary vehicle manufacturer holds the certificate under [§ 1037.622](/cfr/40/1037.622.md).
- (g) We may allow certifying vehicle manufacturers to authorize dealers or distributors to reconfigure/recalibrate vehicles after the vehicles have been introduced into commerce if they have not yet been delivered to the ultimate purchaser as follows:
  - (1) This allowance is limited to changes from one certified configuration to another, as noted in the following examples:
    - (i) If your vehicle family includes certified configurations with different axle ratios, you may authorize changing from one certified axle ratio to another.
    - (ii) You may authorize adding a certified APU to a tractor.
  - (2) Your final ABT report must accurately describe the vehicle's certified configuration as delivered to the ultimate purchaser. This means that the allowance no longer applies after you submit the final ABT report.
  - (3) The vehicle label must accurately reflect the final vehicle configuration.
  - (4) You must keep records to document modifications under this [paragraph (g)](#g).
  - (5) Dealers and distributors must keep a record of your authorizing instructions. Dealers and distributors that fail to follow your instructions or otherwise make unauthorized changes may be committing a tampering violation as described in [40 CFR 1068.105(b)](/cfr/40/1068.105.md?p=b).

## Notes

### Amendments

[81 FR 74048, Oct. 25, 2016, as amended at 86 FR 34490, June 29, 2021]

### Authority

Authority: 42 U.S.C. 7401—7671q.

### Source

Source: 81 FR 74048, Oct. 25, 2016, unless otherwise noted.

### Amendments

[81 FR 74048, Oct. 25, 2016, as amended at 86 FR 34490, June 29, 2021]
