Electric Power Steering System
8-12
■
Maintenance and repair’s supplemental
description:
1. Restart initialization to ECU parameter:
Park UTV on the flat ground and keep the
front wheels pointed forward always.
Pull-out initialization selects connector. (See
Page 12-9 )
Push UTV back and forth for several times,
and turn the wheels several times.
Turn on the main switch and wait for 5
seconds.
Reinsert pin connector to finish the ECU
parameter initialization process.
Then, turn on the main switch; check whether
the fault is removed. If it is not removed, follow
the previous steps of initialization process again.
Because the different mechanical settings of the
UTV, it may require 3-5 times to be repeated in
order to get the correct initialization parameters.
If a customer complaint is “vehicle deviation",
you should take into account the fault causes not
only includes the EPS system, but also includes
a chassis mechanical failure, customers may
use" Deviation" to describe a specific situation.
So four wheel alignment need to be adjusted
first, then ECU replacement and repair needed.
2. The Fault of closing function
The main objective of research and development
was that the EPS system needed to ensure that
the vehicle would still be controlled by the driver
when a malfunction happened.
Therefore, the EPS system has many monitoring
functions, used to identify the sensors, actuators
and the involvement of the EPS system to check
for malfunctions.
If a malfunction leads to the interruption of motor
control, the ECU then closes the function of EPS
system.
Shutting down the EPS system’s will cause the
driver to lose power steering.
But close tolerances are used for preventing
errors in the control motor.
When a fault occurs, power steering stoppage is
a
predetermined
EPS
system
response
characteristic. Although the driver may feel the
characteristics of loss of power steering, with
increased control force, the driver can ensure
the vehicle steering performance is not affected.
When a fault occurs, Neither the EPS steering
system nor hydraulic power steering system
would have power steering. When a fault occurs,
the two systems react similar. The fault occurs,
the EPS system fault indicator light inside of
meter will be on. If above circumstance happens,
the EPS system will have no power steering, and
through
the
instrument
will
show
the
corresponding fault code and remind driver to
take care.
3. Although the mechanical structure of the EPS
system has mechanical limit position, it is still
possible for the EPS system to realize the
function of decreasing steering power before
reaching the mechanical limit position in the form
of a slope curve. Although the customer will feel
the steering resistance increase, when turned to
the limited position the process will become
obviously more smooth.
