Document ID: chunk:federal_register_of_legislation:F2023L00129:reg:10:p58
Version: federal_register_of_legislation:F2023L00129
Segment Type: reg
Provision Reference: reg 10 (pt 58/150)
Character Range: 875011–878280

degrees Celsius) in the case where the coolant temperature has not reached a minimum temperature of at least 333 K (60 degrees Celsius); or
                  (b) At ambient temperatures below 266K (-7 degrees Celsius) in the case of frozen reagent; or
 (c) At ambient temperatures above 308 K (35 degrees Celsius); or
 (d) At elevations above 2,500 meters above sea level; or
(e) Below 400 meters under sea level; or
                  (f) With the exception of electrical circuit failures, at ambient temperatures below 251 K (-22 degrees Celsius).
 A manufacturer may further request approval that an OBD system monitor be temporarily disabled at other ambient temperatures and altitude conditions upon determining that the manufacturer has demonstrated with data and/or an engineering evaluation that misdiagnosis would occur at those ambient conditions because of its effect on the component itself (e.g. component freezing, effect on the compatibility with sensor tolerances).
 Note:  Ambient conditions may be estimated by indirect methods. For example ambient temperature conditions may be determined based on intake air temperature.
5.2.3. Low fuel level
 Manufacturers may request approval to disable monitoring systems that are affected by low fuel level / pressure or running out of fuel (e.g. diagnosis of a malfunction of the fuelling system or misfiring) as follows:
                                                                                                                                                                       Diesel  Gas
                                                                                                                                                                       NG      LPG
    (a) The low fuel level considered for such a disablement shall not exceed 100 litres or 20 per cent of the nominal capacity of the fuel tank, whichever is lower.  X            X
    (b) The low fuel pressure in the tank considered for such a disablement shall not exceed 20 per cent of the usable range of fuel tank pressure.                            X

5.2.4. Vehicle battery or system voltage levels
 Manufacturers may request approval to disable monitoring systems that can be affected by vehicle battery or system voltage levels.
5.2.4.1. Low voltage
 For monitoring systems affected by low vehicle battery or system voltages, manufacturers may request approval to disable monitoring systems when the battery or system voltage is below 90 per cent of the nominal voltage (or 11.0 volts for a 12 volt battery, 22.0 volts for a 24 volt battery). Manufacturers may request approval to utilize a voltage threshold higher than this value to disable system monitoring.
 The manufacturer shall demonstrate that monitoring at the voltages would be unreliable and that either operation of a vehicle below the disablement criteria for extended periods of time is unlikely or the OBD system monitors the battery or system voltage and will detect a malfunction at the voltage used to disable other monitors.
5.2.4.2. High voltage
 For emission related monitoring systems affected by high vehicle battery or system voltages, manufacturers may request approval to disable monitoring systems when the battery or system voltage exceeds