Power Steering System (Diagnostics - Introduction): Other Scion FR-S I

PRECAUTION [07/2013 - 12/2013]

1. HANDLING PRECAUTIONS FOR SRS AIRBAG SYSTEM The vehicle is equipped with a Supplemental Restraint System (SRS). 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 Supplemental Restraint System. Refer to «PRECAUTION [07/2013 - 12/2013]»(ref-612421-S13613575682014042900000) .
2. PRECAUTIONS FOR REMOVAL, INSTALLATION AND REPLACEMENT OF ELECTRONIC MOTOR POWER STEERING COMPONENTS Be sure to align the front wheels straight ahead when removing and installing the power steering link assembly. If disconnecting the steering intermediate shaft and pinion shaft of the power steering link assembly, be sure to place matchmarks before starting the operation. If replacing the power steering ECU assembly, always replace it with a new one (if the power steering ECU assembly is not replaced with a new one, DTCs may be stored). NOTE: Do not use the power steering ECU assembly from another vehicle (display model, etc.). After replacing the steering column assembly or power steering ECU assembly, write the assist map, initialize the rotation angle sensor and calibrate the torque sensor zero point. Refer to «CALIBRATION [07/2013 - ]»(ref-612248-S05281146282014042900000) .
3. HANDLING PRECAUTION When handling electronic parts: Avoid any impact to electronic parts such as ECUs and relays. Replace electronic parts with new ones if dropped or subjected to a severe blow. Do not expose any electronic parts to high temperatures or humidity. Do not touch the connector terminals in order to prevent deformation or malfunctions due to static electricity. When handling the steering column assembly: 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. Do not pull the wire harness when moving the steering column assembly. When disconnecting the connectors related to the power steering system, turn the ignition switch to ON, center the steering wheel, turn the ignition switch off, disconnect the negative (-) battery terminal, and then disconnect the connectors.
4. PRECAUTIONS FOR CAN COMMUNICATION Perform troubleshooting for the communication line problems when DTCs of the CAN communication system are output. Be sure to start troubleshooting the power steering system after confirming that the CAN communication system is normal. Since the CAN communication line has a specific length and route, it cannot be repaired temporarily with a bypass wire, etc.

PRECAUTION [12/2013 - ]

1. IGNITION SWITCH EXPRESSIONS 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 Service Information. Expression Ignition Switch (Position) Engine Switch (Condition) Ignition Switch off LOCK Off (Lock) Ignition Switch ACC ACC On (ACC) Ignition Switch ON ON On (IG) Engine Start START On (Start)
2. HANDLING PRECAUTIONS FOR SRS AIRBAG SYSTEM The vehicle is equipped with a Supplemental Restraint System (SRS). 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 Supplemental Restraint System. Refer to «PRECAUTION [12/2013 - ]»(ref-612421-S24190999222014042900000) .
3. PRECAUTIONS FOR REMOVAL, INSTALLATION AND REPLACEMENT OF ELECTRONIC MOTOR POWER STEERING COMPONENTS Be sure to align the front wheels straight ahead when removing and installing the power steering link assembly. If disconnecting the steering intermediate shaft and pinion shaft of the power steering link assembly, be sure to place matchmarks before starting the operation. If replacing the power steering ECU assembly, always replace it with a new one (if the power steering ECU assembly is not replaced with a new one, DTCs may be stored). NOTE: Do not use the power steering ECU assembly from another vehicle (display model, etc.). After replacing the steering column assembly or power steering ECU assembly, write the assist map, initialize the rotation angle sensor and calibrate the torque sensor zero point. Refer to «CALIBRATION [07/2013 - ]»(ref-612248-S05281146282014042900000) .
4. HANDLING PRECAUTION When handling electronic parts: Avoid any impact to electronic parts such as ECUs and relays. Replace electronic parts with new ones if dropped or subjected to a severe blow. Do not expose any electronic parts to high temperatures or humidity. Do not touch the connector terminals in order to prevent deformation or malfunctions due to static electricity. When handling the steering column assembly: 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. Do not pull the wire harness when moving the steering column assembly. When disconnecting the connectors related to the power steering system, turn the ignition switch to ON, center the steering wheel, turn the ignition switch off, disconnect the negative (-) battery terminal, and then disconnect the connectors.
5. PRECAUTIONS FOR CAN COMMUNICATION Perform troubleshooting for the communication line problems when DTCs of the CAN communication system are output. Be sure to start troubleshooting the power steering system after confirming that the CAN communication system is normal. Since the CAN communication line has a specific length and route, it cannot be repaired temporarily with a bypass wire, etc.

Scheme 3

Scheme 4

FREEZE FRAME DATA [07/2013 - ]

1. FREEZE FRAME DATA Turn the ignition switch off. Connect the Techstream to the DLC3. Turn the ignition switch to ON. Turn the Techstream on. Enter the following menus: Chassis / EMPS / Trouble Codes. According to the display on the Techstream, select the freeze frame data. EMPS Tester Display Measurement Item/Range Normal Condition Diagnostic Note Meter Vehicle Velocity Vehicle speed from skid control ECU/ Min.: 0.0 km/h (0.0 mph) Max.: 300.0 km/h (186.4 mph) 0 km/h (0 mph) The vehicle is stopped. No significant fluctuation The vehicle is driven at a constant speed. Engine Revolution Engine speed/ Min.: 0 rpm Max.: 12800 rpm No significant fluctuation The engine is running at a constant speed. Motor Actual Current Amount of current to motor/ Min.: -327.68 A Max.: 327.67 A Value changes in proportion to steering effort The engine is running and the steering wheel is being turned. Command Value Current Demanded amount of current to motor/ Min.: -327.68 A Max.: 327.67 A Value changes in proportion to steering effort The engine is running and the steering wheel is being turned. Steering Angle Velocity Steering angle speed/ Min.: -32768 deg/s Max.: 32767 deg/s Value changes in proportion to steering effort The engine is running and the steering wheel is being turned. Thermistor Temperature ECU substrate temperature/ Min.: -50.0°C (-58.0°F) Max.: 150.0°C (302.0°F) - The ignition switch is ON. PIG Power Supply Power source voltage to active motor/ Min.: 0.0000 V Max.: 20.1531 V 9 to 16 V The engine is running and power steering is operating. IG Power Supply ECU power source voltage/ Min.: 0.0000 V Max.: 20.1531 V 9 to 16 V The ignition switch is ON. Steering Wheel Torque Steering wheel torque/ Min.: -7.00 Nm Max.: 7.00 Nm Value changes in proportion to steering effort The engine is running and the steering wheel is being turned. Motor Rotation Angle Motor rotation angle/ Min.: 0.000 deg Max.: 360.000 deg Motor rotation angle value changes from 0 to 360 deg The engine is running and the steering wheel is being turned. Command Val Current 2 Demanded amount of current to motor/ Min.: -327.68 A Max.: 327.67 A Value changes in proportion to steering effort The engine is running and the steering wheel is being turned. PIG2 Voltage Coil rear pressurization voltage/ Min.: 0.000 V Max.: 98.000 V Approximately 27 V The engine is running and the steering wheel is not being turned. Value changes between 16 and 35 V The engine is running and the steering wheel is being turned. Motor Voltage Motor power supply voltage/ Min.: 0.000 V Max.: 98.000 V Approximately 27 V The engine is running and the steering wheel is not being turned. Value changes between 4 and 35 V The engine is running and the steering wheel is being turned. Motor Terminal Volt(U) Motor terminal voltage (U phase)/ Min.: 0.000 V Max.: 98.000 V Value changes between 4 and 35 V The engine is running and the steering wheel is being turned. Motor Terminal Volt(V) Motor terminal voltage (V phase)/ Min.: 0.000 V Max.: 98.000 V Value changes between 4 and 35 V The engine is running and the steering wheel is being turned. Motor Terminal Volt(W) Motor terminal voltage (W phase)/ Min.: 0.000 V Max.: 98.000 V Value changes between 4 and 35 V The engine is running and the steering wheel is being turned. Torque Sensor 1 Output Torque sensor 1 output voltage/ Min.: 0.0000 V Max.: 5.0000 V 2.3 to 2.7 V The engine is running and the steering wheel is not turned (without load). 2.3 to 3.8 V The engine is running and the steering wheel is turned to the right when the vehicle is stopped. 1.2 to 2.7 V The engine is running and the steering wheel is turned to the left when the vehicle is stopped. Torque Sensor 2 Output Torque sensor 2 output voltage/ Min.: 0.0000 V Max.: 5.0000 V 2.3 to 2.7 V The engine is running and the steering wheel is not turned (without load). 1.2 to 2.7 V The engine is running and the steering wheel is turned to the right when the vehicle is stopped. 2.3 to 3.8 V The engine is running and the steering wheel is turned to the left when the vehicle is stopped. TRQ1 Zero Point Value Torque sensor 1 zero point voltage/ Min.: 0.0000 V Max.: 5.0000 V Values differ depending on vehicle The engine is running and the steering wheel is not being turned. TRQ2 Zero Point Value Torque sensor 2 zero point voltage/ Min.: 0.0000 V Max.: 5.0000 V Values differ depending on vehicle The engine is running and the steering wheel is not being turned.

FAIL-SAFE CHART [07/2013 - ]

If a problem occurs in the power steering system, the EPS warning light comes on in the combination meter and the power steering assist is stopped, locked at a particular point, or decreased simultaneously to protect the system.

POWER STEERING SYSTEM

HINT

1. *1: When the DTC is stored while the engine is running.
2. *2: When the DTC is stored before the engine is started.
3. The amount of power assist may be decreased to prevent the motor and ECUs from overheating if the steering wheel is continuously turned when the vehicle is either stopped or driven at a low speed, or if the steering wheel is kept at either full lock position for a long time. In such cases, the amount of power assist returns to normal if the steering wheel is not turned for approximately 10 minutes with the engine idling.
4. If the battery is not sufficiently charged or the voltage decreases temporarily, the amount of power assist is reduced and the EPS warning light comes on. In such cases, the amount of power assist returns normal when the battery voltage recovers.