This section describes how you may implement design changes for an emergency vehicle that has already been placed into service to ensure that the vehicle will perform properly in emergency situations. This applies for any light-duty vehicle, light-duty truck, or heavy-duty vehicle meeting the definition of emergency vehicle in 40 CFR 86.004-2 or 86.1803. In this section, “you” refers to the certifying manufacturer and “we” refers to the EPA Administrator and any authorized representatives.

(a) You must notify us in writing of your intent to install or distribute an emergency vehicle field modification (EVFM). In some cases you may install or distribute an EVFM only with our advance approval, as specified in this section.

(b) Include in your notification a full description of the EVFM and any documentation to support your determination that the EVFM is necessary to prevent the vehicle from losing speed, torque, or power due to abnormal conditions of its emission control system, or to prevent such abnormal conditions from occurring during operation related to emergency response. Examples of such abnormal conditions may include excessive exhaust backpressure from an overloaded particulate trap, or running out of diesel exhaust fluid for engines that rely on urea-based selective catalytic reduction. Your determination must be based on an engineering evaluation or testing or both.

(c) You may need our advance approval for your EVFM, as follows:

(1) Where the proposed EVFM is identical to an AECD we approved under this part for an engine family currently in production, no approval of the proposed EVFM is necessary.

(2) Where the proposed EVFM is for an engine family currently in production but the applicable demonstration is based on an AECD we approved under this part for an engine family no longer in production, you must describe to us how your proposed EVFM differs from the approved AECD. Unless we say otherwise, your proposed EVFM is deemed approved 30 days after you notify us.

(3) If we have not approved an EVFM comparable to the one you are proposing, you must get our approval before installing or distributing it. In this case, we may request additional information to support your determination under paragraph (b) of this section, as follows:

(i) If we request additional information and you do not provide it within 30 days after we ask, we may deem that you have retracted your request for our approval; however, we may extend this deadline for submitting the additional information.

(ii) We will deny your request if we determine that the EVFM is not necessary to prevent the vehicle from losing speed, torque, or power due abnormal conditions of the emission control system, or to prevent such abnormal conditions from occurring, during operation related to emergency response.

(iii) Unless we say otherwise, your proposed EVFM is deemed approved 30 days after we acknowledge that you have provided us with all the additional information we have specified.

(4) If your proposed EVFM is deemed to be approved under paragraph (c)(2) or (3) of this section and we find later that your EVFM in fact does not meet the requirements of this section, we may require you to no longer install or distribute it.

[77 FR 34145, June 8, 2012]