SASO S TANDAR D SASO/FDS 31838/2020
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 واﻟ واﻟ  ﻟﻠ  اﻟ  اﻟﻬ 
Saudi Standards, Metrology and Quality Org. (SAS O) 
 
      
 
 
 
 
 
Final Draft Standard  
 
   
SASO /FDS/31838/2020  
   
 
Road vehicles - Accele rator control systems  
 
 
    
ICS: 43.040.30 
 
This document is a draft Saudi Standard circulated for comments . It is, therefore, 
subject to alteration and modification and may not be referred to as a Saudi 
Standard until approved by SASO . SASO S TANDAR D SASO/FDS 31838/2020
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Conte nts 
 
1- Scope and field of the application ............... ................ ................ ................ ............ ......... 1 
 
2- Terms and definitions  .............................................................. ......................................... 1 
 
3- Technical requirements ............................................................... ..................................... 4 
 
Bibliography   ............................................................. ...............................................................  5 SASO S TANDAR D SASO/FDS 31838/2020
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 Road vehicles - Accelerator control systems 
 
 
1- Scope and field of the appl ication 
This standard specifies technical requirements for the return o f a vehicle's throttle to the idle 
position when the driver removes the actuating force from the a ccelerator control or in the 
event of a severance or disconnection in the accelerator contro l system. 
 
This standard applies to passenger cars, multipurpose passenger  vehicles, trucks, and buses. 
 
2- Terms and definitions 
For the purposes of this standard, the following terms and defi nitions are applied: 
2.1 Passenge r car 
A motor vehicle with motive power, designed for carrying 10 per sons or less including the 
driver and their luggage, except a low-speed vehicle, multipurp ose passenger vehicle, or trailer. 
2.2 Multipurpose passe nger vehicle 
A motor vehicle with motive power, designed to carry 10 persons  or less or goods equivalent 
by weight which is constructed ei ther on a truck chassis or wit h special features for occasional 
off-road operation. Except a low-speed vehicle or trailer 
2.3 Truck 
A motor vehicle with motive power, designed primarily for the t ransportation of property, 
special purpose equipment, or towing a trailer except a trailer . 
2.4 Bus 
A motor vehicle with motive power , designed for carrying more t han 10 persons, except a 
trailer. 
2.5 Driver-operated accelerator control syste m 
All vehicle components, except the fuel metering device, that r egulate engine speed in direct 
response to movement of the driver-operated control and that re turn the throttle to the idle 
position upon release of the actuating force. 
2.6 Throttle 
The component of the fuel-metering device that connects to the driver-operated accelerator 
control system and that by input from the driver-operated accel erator control system controls 
the engine speed. 
2.7 Fuel metering device 
The carburetor, or in the case of certain engines the fuel inje ctor, fuel distributor or fuel injection 
pump. 
2.8 Idle position 
The position of the throttle at which it first comes in contact  with an engine idle speed control 
appropriate for existing conditions according to the manufactur ers' recommendations. These 
conditions include, but are not limited to, engine speed adjust ments for cold engine, air 
conditioning, and emission contr ol, and the use of throttle set ting devices. 
 
 SASO S TANDAR D SASO/FDS 31838/2020
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 2.9 Ambient tempe rature 
The surrounding air temperature, at a distance such that it is not significantly affected by heat 
from the vehicle under test. 
Note: In the case of vehicles powered by electric motors, the w ords throttle and idle refer to the 
motor speed controller and motor shutdown, respectively. 
 
3- Technical requirements 
3.1 The vehicle shall meet the following requirements when the eng ine is running under any 
load condition, and at any ambient temperature between − 40 deg rees Celsius and + 52 degrees 
Celsius after 12 hours of conditioning at any temperature withi n that range. 
3.2 The maximum time to return to idle position shall be as follow ing: 
a) 1 second for vehicles of 4536 kilograms or less gross vehicle weight rating (GVWR), and 
b) 2 seconds for vehicles of more than 4536 kilograms gross vehic le weight rating (GVWR). 
3.3 There shall be at least two sources of energy capable of retur ning the throttle to the idle 
position within the time limit specified in item 3.2 from any a ccelerator position or speed 
whenever the driver removes the opposing actuating force. 3.4 In the event of failure of one source of energy by a single se verance or disconnection, the 
throttle shall return to the idle position within the time limi ts specified in item 3.2, from any 
accelerator position or speed whenever the driver removes the o pposing actuating force. 
3.5 The throttle shall return to the idle position from any accele rator position or any speed of 
which the engine is capable whenever anyone component of the ac celerator control system is 
disconnected or severed at a single point. 
3.5.1  The return to idle shall occur within the time limit specified  in item 3.2, measured either 
from the time of severance or disconnection or from the first r emoval of the opposing actuating 
force by the driver. SASO S TANDAR D SASO/FDS 31838/2020
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Bibliography  
 
[1] 49 Subtitle B-Chapter V-Part 571-Subpart B Section 124  
(FMVSS  571.124)  "Accelerator control systems".