This section specifies requirements that apply for certified automatic engine shutdown (AES) systems modeled under Sec. 1037.520. It does not apply for AES systems you do not model under Sec. 1037.520.
(a) Minimum requirements. Your AES system must meet all of the requirements of this paragraph (a) to be modeled under Sec. 1037.520. The system must shut down the engine within 300 seconds when all the following conditions are met:
(1) The transmission is set in neutral with the parking brake engaged (or the transmission is set to park if so equipped).
(2) The operator has not reset the system timer within the 300 seconds by changing the position of the accelerator, brake, or clutch pedal; or by some other mechanism we approve.
(3) None of the override conditions of paragraph (b) of this section are met.
(b) Override conditions. The system may delay shutting the engine down while any of the conditions of this paragraph (b) apply. Engines equipped with auto restart may restart during override conditions. Note that these conditions allow the system to delay shutdown or restart, but do not allow it to reset the timer. The system may delay shutdown--
(1) While an exhaust emission control device is regenerating. The period considered to be regeneration for purposes of this allowance must be consistent with good engineering judgment and may differ in length from the period considered to be regeneration for other purposes. For example, in some cases it may be appropriate to include a cool down period for this purpose but not for infrequent regeneration adjustment factors.
(2) If necessary while servicing the vehicle, provided the deactivation of the AES system is accomplished using a diagnostic scan tool. The system must be automatically reactivated when the engine is shutdown for more than 60 minutes.
(3) If the vehicle's main battery state-of-charge is not sufficient to allow the main engine to be restarted.
(4) If the external ambient temperature reaches a level below which or above which the cabin temperature cannot be maintained within reasonable heat or cold exposure threshold limit values for the health and safety of the operator (not merely comfort).
(5) If the vehicle's engine coolant temperature is too low according to the manufacturer's engine protection guidance. This may also apply for fuel or oil temperatures. This allows the engine to continue operating until it reaches a predefined temperature at which the shutdown sequence of paragraph (a) of this section would resume.
(6) The system may delay shutdown while the vehicle's main engine is operating in power take-off (PTO) mode. For purposes of this paragraph (b)(6), an engine is considered to be in PTO mode when a switch or setting designating PTO mode is enabled.
(c) Adjustments to AES systems. (1) The AES system may include an expiration point (in miles) after which the AES system may be disabled. If your vehicle is equipped with an AES system that expires before 1,259,000 miles, adjust the model input as follows, rounded to the nearest 0.1 g/ton-mile: AES Input = 5 g CO2/ton-mile x (miles at expiration/1,259,000 miles)
(1) The AES system may include an expiration point (in miles) after which the AES system may be disabled. If your vehicle is equipped with an AES system that expires before 1,259,000 miles, adjust the model input as follows, rounded to the nearest 0.1 g/ton-mile: AES Input = 5 g CO2/ton-mile x (miles at expiration/1,259,000 miles)
(2) For AES systems designed to limit idling to a specific number of hours less than 1,800 hours over any 12-month period, calculate an adjusted AES input using the following equation, rounded to the nearest 0.1 g/ton- mile: AES Input = 5 g CO2/ton-mile x (1-(maximum allowable number of idling hours per year/1,800 hours)). This is an annual allowance that starts when the vehicle is new and resets every 12 months after that. Manufacturers may propose an alternative method based on operating hours or miles instead of years.
(d) Adjustable parameters. Provisions that apply generally with respect to adjustable parameters also apply to the AES system operating parameters, except the following are not considered to be adjustable parameters:
(1) Accelerator, brake, and clutch pedals, with respect to resetting the idle timer. Parameters associated with other timer reset mechanisms we approve are also not adjustable parameters.
(2) Bypass parameters allowed for vehicle service under paragraph (b)(2) of this section.
(3) Parameters that are adjustable only after the expiration point. [76 FR 57398, Sept. 15, 2011, as amended at 78 FR 36394, June 17, 2013]