Autel MaxiCheck EPB - Manual (Page 6)

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constantly monitoring the WSS, the Vehicle Speed Sensor, and the
G-sensor.
Diagnosing an ABS problem should always start with a visual
inspection of all brake components, then you will need to retrieve
ABS DTCs to tell you where the problem is.
SRS - “Supplemental Restraint System” is made up of Impact
Sensors, a Control Module, and Airbags. When the impact sensors
detect a collision they send an extremely fast signal to the control
module, which relays that signal to the airbags, deploying them to
help prevent vehicle occupants from hitting interior objects such as
steering wheels, dashboards, and the like. When the control module
detects a problem with the airbags or sensors the Malfunction
Indicator Light (MIL) will turn on。
2.6 SAS review
SAS, steering angle sensor, measures the rotation angle, angle
velocity and direction of the steering wheel, providing information on
the direction in which the driver wishes to go. Steering angle sensors
are required for systems such as ESC and are also used in electric
power steering and active steering systems (EPS or AFS) as well as
parking assistance systems and curve lights.
A scan tool can be used to obtain this data in degrees. The SAS is
located in a sensor cluster in the steering column. The cluster always
has more than one steering position sensor for redundancy and to
confirm data. The ESC module must receive two signals to confirm
the steering wheel position. These signals are often out of phase with
each other.
Many vehicles require the SAS be reset or recalibrated after an
alignment is performed or parts in the steering system are replaced。
There are three types of reset procedures, systems that self calibrate
on their own, vehicles that require specific wires or buttons be
pressed and, systems that require recalibration with a scan tool.