Document ID: chunk:federal_register_of_legislation:F2017L01229:body:0:p10
Version: federal_register_of_legislation:F2017L01229
Segment Type: other
Provision Reference: 
Character Range: 26793–29535

ESC Off and other system controls
 The manufacturer may include an "ESC Off" control, which shall be illuminated when the vehicle's headlamps are activated, and which has a purpose to place the ESC system in a mode in which it will no longer satisfy the performance requirements of paragraphs 7., 7.1., 7.2. and 7.3. Manufacturers may also provide controls for other systems that have an ancillary effect upon ESC operation. Controls of either kind that place the ESC system in a mode in which it may no longer satisfy the performance requirements of paragraphs 7., 7.1., 7.2. and 7.3. are permitted, provided that the system also meets the requirements of paragraphs 7.5.1., 7.5.2. and 7.5.3.
7.5.1. The vehicle's ESC system shall always return to the manufacturer's original default mode that satisfies the requirements of paragraphs 6. and 7. at the initiation of each new ignition cycle, regardless of what mode the driver had previously selected. However, the vehicle's ESC system need not return to a mode that satisfies the requirements of paragraphs 7. through 7.3. at the initiation of each new ignition cycle if:
7.5.1.1. The vehicle is in a four-wheel drive configuration which has the effect of locking the drive gears at the front and rear axles together and providing an additional gear reduction between the engine speed and vehicle speed of at least 1.6, selected by the driver for low-speed, off-road driving; or
7.5.1.2. The vehicle is in a four-wheel drive configuration selected by the driver that is designed for operation at higher speeds on snow-, sand-, or dirt-packed roads and that has the effect of locking the drive gears at the front and rear axles together, provided that in this mode the vehicle meets the stability performance requirements of paragraphs 7.1. and 7.2. under the test conditions specified in paragraph 8. However, if the system has more than one ESC mode that satisfies the requirements of paragraphs 7.1. and 7.2. within the drive configuration selected for the previous ignition cycle, the ESC shall return to the manufacturer's original default ESC mode for that drive configuration at the initiation of each new ignition cycle.
7.5.2. A control, whose only purpose is to place the ESC system in a mode in which it will no longer satisfy the performance requirements of paragraphs 7., 7.1., 7.2. and 7.3., shall fulfil the relevant technical requirements of Regulation No. 121.
7.5.3. A control for an ESC system whose purpose is to place the ESC system in different modes, at least one of which may no longer satisfy the performance requirements of paragraphs 7., 7.1., 7.2., and 7.3., shall fulfil the relevant technical requirements of Regulation No. 121.
 Alternatively, in the case where