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TOYOTA TECHNICAL
The EPS motor, torque sensor
and motor rotation angle sensor
are built into the steering column.
The Electronic Power Steering
ECU is secured to the cowl with
three studs and nuts.
ELECTRONIC POWER
STEERING SYSTEM
PRECAUTIONS
When handling the electronic
parts, avoid any impact to parts
such as ECUs and relays. Replace
with new if dropped or subjected
to a severe blow.
Do not expose any electronic
parts to high temperatures and
humidity.
Do not touch the connector
terminals, in order to prevent malfunctions
due to static electricity.
When handling the steering column
assembly, avoid any impact
to the steering column assembly,
especially the motor and torque
sensor.
Replace with new (motor and/
or torque sensor) if dropped or
subjected to a severe blow.
When disconnecting and reconnecting
the electronic steering
system connectors, turn the ignition
switch to the ON position,
center the steering wheel, turn
the ignition OFF, and then disconnect
the sensors.
PRECAUTIONS FOR CAN
COMMUNICATION
High-speed CAN communication
lines are used to
The torque sensor detects the amount of torque applied
to the torsion bar by the steering wheel.
receive information from the skid
control ECU and the ECM, and to
transmit warnings to the combination
meter.
When any problems arise in the
CAN communication lines, DTCs
of the CAN communication line
are output.
Perform troubleshooting for
communication line problems
when the CAN communication
DTCs are output. Be sure to start
troubleshooting on the electronic
power steering system after
confi rming that the CAN communication
system is functioning
normally.
Since the CAN communication
line features its own length and
route, it cannot be repaired with a
bypass wire, etc.
INSPECTING THE
TORQUE SENSOR
With torque sensor connector
connected (where DTCs are indicated),
turn the ignition switch
ON.
Measure the voltage at the EPS
ECU at the appropriate ECU terminals.
If the specifi cations are not
met, replace the steering column
assembly.
Locations of the EPS ECU terminals
for checking torque sensor
voltage conditions.
16 STAR Service News
Spring 2010