Power Steering System
POWER ASSIST SYSTEMS: POWER STEERING SYSTEM (for 2ZR-FE): PRECAUTION
1. IGNITION SWITCH EXPRESSIONS
HINT
The type of ignition switch used on this model differs according to the specifications of the vehicle. The expressions listed in the table below are used in this section.
2. HANDLING PRECAUTIONS FOR SRS AIRBAG SYSTEM
(a) The vehicle is equipped with an SRS (Supplemental Restraint System). Failure to carry out service operations in the correct sequence could cause the SRS to unexpectedly deploy during servicing. This may cause a serious accident.
Before servicing (including inspection, replacement, removal and installation of parts), be sure to read the precautionary notices for the Supplemental Restraint System Service Precautions.
3. PRECAUTIONS FOR REMOVAL, INSTALLATION AND REPLACEMENT OF ELECTRONIC MOTOR POWER STEERING COMPONENTS
(a) Be sure to align the front wheels straight ahead when removing and installing the power steering gear assembly.
(b) If disconnecting the steering sliding yoke sub-assembly and the pinion shaft of the power steering gear assembly, be sure to place matchmarks before starting the operation.
(c) After replacing the steering column assembly or power steering ECU, calibrate the torque sensor zero point Programming and Relearning.
4. HANDLING PRECAUTION
(a) When handling electronic parts:
(1) Avoid any impact to parts such as ECUs and relays. Replace them with new ones if dropped or subjected to a severe blow.
(2) Do not expose to high temperatures or humidity.
(3) In order to prevent deformation or malfunctions due to static electricity, do not touch the connector terminals.
(b) When handling power steering ECU:
(1) When the power steering ECU has been replaced with a new one, perform the assist map writing and the torque sensor zero point calibration Programming and Relearning.
(c) When handling the steering column assembly:
(1) Avoid any impact to the steering column assembly, especially to the motor and torque sensor. Replace them with new ones if dropped or subjected to a severe blow.
(2) Do not pull the wire harness when moving the steering column assembly.
(3) When the steering column assembly has been replaced, perform the torque sensor zero point calibration after initializing the torque sensor zero point Programming and Relearning.
(d) When disconnecting and reconnecting the connectors:
(1) Before disconnecting the connectors related to the power steering system, turn the ignition switch on (IG), center the steering wheel, turn the ignition switch off, and then disconnect the connectors.
(2) Before reconnecting the connectors related to the power steering system, ensure that the ignition switch is off. Then center the steering wheel and turn the ignition switch on (IG).
NOTICE:
Do not turn the ignition switch on (IG) when the steering wheel is not centered.
(3) If the above operations are not carried out properly, the steering center point (zero point) will deviate, which may lead to a difference in steering effort between turning right and left. If there is a difference in steering effort between turning right and left, perform the torque sensor zero point calibration after initializing the torque sensor zero point Programming and Relearning.
5. PRECAUTIONS FOR CAN COMMUNICATION
(a) CAN communication lines are used to receive information from the skid control ECU and the ECM, and to transmit warnings to the combination meter. When there are any problems in the CAN communication lines, DTCs of the CAN communication line are output.
(b) Perform troubleshooting of the communication line problems when the CAN communication DTCs are output. Be sure to start troubleshooting on the electronic power steering system after confirming that the CAN communication system is normal.
(c) Since the CAN communication line has its own length and route, it cannot be temporarily repaired with a bypass wire, etc.