[Code of Federal Regulations]
[Title 40, Volume 17]
[Revised as of July 1, 2004]
From the U.S. Government Printing Office via GPO Access
[CITE: 40CFR86.230-94]

[Page 583-585]
 
                   TITLE 40--PROTECTION OF ENVIRONMENT
 
         CHAPTER I--ENVIRONMENTAL PROTECTION AGENCY (CONTINUED)
 
PART 86_CONTROL OF EMISSIONS FROM NEW AND IN-USE HIGHWAY VEHICLES AND 
ENGINES--Table of Contents
 
 Subpart C_Emission Regulations for 1994 and Later Model Year Gasoline-
 
Sec. 86.230-94  Test sequence: general requirements.

    (a) Sequence steps. Figure C94-1 shows the steps encountered as the 
test vehicle undergoes the procedures subsequently described, to 
determine conformity with the standards set forth.

[[Page 584]]

[GRAPHIC] [TIFF OMITTED] TR06OC93.167

    (b) Driving schedule. The Urban Dynamometer Driving Schedule (UDDS) 
test procedure (see Sec. 86.115 and appendix I to this part) is used 
for vehicle preconditioning and testing.
    (c) Ambient temperature level. (1) Ambient temperature levels 
encountered by the test vehicle shall average 20 [deg]F5 [deg]F (-7 [deg]C2.8 [deg]C) and 
shall not be less than 10 [deg]F (-14 [deg]C) nor more than

[[Page 585]]

30 [deg]F (-1 [deg]C) during vehicle preconditioning, except for 
preconditioning performed in accordance with Sec. 86.232(a)(7), and 
during all emission testing.
    (2) The ambient temperature reported shall be a simple average of 
the test cell temperatures measured at constant intervals no more than 
one minute apart. Before the driving cycle may begin, the test cell 
temperature shall be 20 [deg]F3 [deg]F (-7 
[deg]C1.7 [deg]C) when measured in accordance with 
paragraph (e)(2) of this section. The temperature may not exceed 25 
[deg]F (-4 [deg]C) or fall below 15 [deg]F (-9 [deg]C) for more than 
three consecutive minutes during the test.
    (d) Vehicle positioning. The vehicle shall be approximately level 
during all phases of the test sequence to prevent abnormal fuel 
distribution.
    (e) Engine compartment cooling. (1) Fixed speed air cooling of the 
engine compartment with the compartment cover open shall be utilized 
during testing that is conducted by the Administrator and, optionally 
for certification testing, by the manufacturer. If a separate movable 
fan is used, it shall be squarely positioned within 12 inches (30.5 
centimeters) of the front of vehicles with front engine compartments. In 
the case of vehicles with rear engine compartments (or if special 
designs make the normal front engine positioning impractical), the 
cooling fan shall be placed in a position to provide sufficient air to 
maintain vehicle cooling. The fan capacity shall normally not exceed 
5,300 cfm (2.50 cubic meters per second). If, however, the manufacturer 
showed (as provided in Sec. 86.135-94(b)) that additional cooling is 
necessary, the fan capacity may be increased or additional fans used if 
approved in advance by the Administrator. The cooling air temperature 
shall be measured at the inlet to the fan.
    (2) In lieu of using a separate fan, an air handling system that is 
integral with the test cell may be used provided comparable air movement 
is obtained. The cooling air temperature shall be measured in the center 
of a vertical plane that is located approximately 2 feet in front of the 
vehicle.
    (3) The manufacturer may use, for certification testing, alternative 
engine compartment cooling fans or systems, including those which 
provide a variable air flow, if the manufacturer has determined that 
comparable results are obtained.
    (f) Heater and defroster usage. The heater and defroster may be used 
at any temperature and fan settings.