PRECAUTION [03/2012 - 07/2012]
- PRECAUTION FOR DISCONNECTING THE CABLE FROM THE NEGATIVE BATTERY NOTE: When disconnecting the cable from the negative (-) battery terminal, initialize the following systems after the cable is reconnected: System See Procedure Parking Assist Monitor System Refer to «INITIALIZATION [03/2012 - 07/2012]»(ref-602551-S24591545042014030500000) Back Door Closer System Refer to «INITIALIZATION [03/2012 - 07/2012]»(ref-602551-S24591545042014030500000) Power Back Door System Refer to «INITIALIZATION [03/2012 - 07/2012]»(ref-602551-S24591545042014030500000)
- 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 the Supplemental Restraint System. Refer to «PRECAUTION [03/2012 - 07/2012]»(ref-602724-S22259792752014030500000) .
- PRECAUTIONS FOR REMOVAL, INSTALLATION AND REPLACEMENT OF ELECTRONIC MOTOR POWER STEERING COMPONENTS After replacing the power steering ECU assembly, clear the rotation angle sensor calibration value, initialize the rotation angle sensor, and calibrate the torque sensor zero point. Refer to «CALIBRATION [03/2012 - ]»(ref-602566-S35786595422014030500000) .
- HANDLING PRECAUTION When handling the electronic parts: Avoid any impact to electronic parts such as ECUs and relays. Replace them with new ones if dropped or subjected to a severe blow. Do not expose any electronic parts to high temperatures or humidity. In order to prevent deformation or malfunctions due to static electricity, do not touch the connector terminals. Before disconnecting the connectors related to the electronic power steering system, turn the engine switch on (IG), center the steering wheel and then turn the engine switch off.
- PRECAUTIONS FOR CAN COMMUNICATION 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. Perform troubleshooting for the communication line problems when DTCs of the CAN communication are output. Be sure to start troubleshooting on the power steering system after confirming that the CAN communication system is normal. Since the CAN communication line has its own length and route, it cannot be repaired temporarily with a bypass wire, etc.
PRECAUTION [07/2012 - ]
- PRECAUTION FOR DISCONNECTING THE CABLE FROM THE NEGATIVE BATTERY NOTE: When disconnecting the cable from the negative (-) battery terminal, initialize the following systems after the cable is reconnected: System See Procedure Parking Assist Monitor System Refer to «INITIALIZATION [07/2012 - ]»(ref-602551-S38908041872014030500000) Back Door Closer System Refer to «INITIALIZATION [07/2012 - ]»(ref-602551-S38908041872014030500000) Power Back Door System Refer to «INITIALIZATION [07/2012 - ]»(ref-602551-S38908041872014030500000)
- 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 the Supplemental Restraint System. Refer to «PRECAUTION [07/2012 - ]»(ref-602724-S13282392072014030500000) .
- PRECAUTIONS FOR REMOVAL, INSTALLATION AND REPLACEMENT OF ELECTRONIC MOTOR POWER STEERING COMPONENTS After replacing the power steering ECU assembly, clear the rotation angle sensor calibration value, initialize the rotation angle sensor, and calibrate the torque sensor zero point. Refer to «CALIBRATION [03/2012 - ]»(ref-602566-S35786595422014030500000) .
- HANDLING PRECAUTION When handling the electronic parts: Avoid any impact to electronic parts such as ECUs and relays. Replace them with new ones if dropped or subjected to a severe blow. Do not expose any electronic parts to high temperatures or humidity. In order to prevent deformation or malfunctions due to static electricity, do not touch the connector terminals. Before disconnecting the connectors related to the electronic power steering system, turn the engine switch on (IG), center the steering wheel and then turn the engine switch off.
- PRECAUTIONS FOR CAN COMMUNICATION 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. Perform troubleshooting for the communication line problems when DTCs of the CAN communication are output. Be sure to start troubleshooting on the power steering system after confirming that the CAN communication system is normal. Since the CAN communication line has its own length and route, it cannot be repaired temporarily with a bypass wire, etc.
Scheme 3
Scheme 4
Scheme 5
![Scheme 5: SYSTEM DIAGRAM [03/2012 - ]](https://i.diagnostdata.com/repair/92/9235f7acac0407c54f7ffe54c2c07e376796f8f3fd723584d2e773a7e8f9d3ce.webp)
| Transmitting ECU (Transmitter) | Receiving ECU | Signal | Communication Method |
|---|---|---|---|
| ECM | Power Steering ECU | Engine speed signal Engine variation information signal TC terminal condition 2WD or 4WD information signal Transmission information signal Gear information signal Diagnoses transmitting system No. signal | CAN |
| Skid Control ECU | Power Steering ECU | Vehicle speed (SP1) status signal Vehicle speed (SP1) signal Test mode signal VSC controlling signal ABS controlling signal FR, FL, RR and RL wheel speed signal FR, FL, RR and RL wheel speed sensor error signal Yaw rate 1 zero point signal GL1 zero point value signal Yaw G sensor installation information signal Yaw rate zero point error signal FR, FL, RR and RL wheel speed sensor power supply drop state signal TRC operating signal Stop light switch signal Brake control distinction signal Vehicle state quantity signal Target additional torque signal Target steering angle, target additional torque validity signal Yaw rate 2 zero point value signal GL 2 zero point value signal G sensor zero point un-corrected status signal Yaw rate zero point un-corrected status signal Yaw rate zero point update information signal Torque steer assist torque signal Torque steer occurring signal Steering vibration occurring signal Torque steer assist torque validity signal Torque steer drive torque signal | CAN |
| Steering Angle Sensor | Power Steering ECU | Data continuity (valid/invalid) signal +B open circuit signal Sensor malfunction signal Steering angle signal Zero point memory (in sensor) valid/invalid signal Zero point (stored in steering angle sensor) signal | CAN |
| Yaw Rate Sensor | Power Steering ECU | Yaw rate sensor 1 and 2 signal Yaw rate sensor 1and 2 (valid/invalid) signal Sensor power supply voltage (IG) (valid/invalid) signal Yaw rate sensor 1 and 2 error signal GL1, GX and GL2, GY sensor signal GL1, GX and GL2, GY sensor (valid/invalid) signal GL1, GX and GL2, GY sensor error signal Data output response non-request/request signal Yaw G sensor CPU monitor signal Sensor type distinction signal Yaw rate difference value signal | CAN |
| Main Body ECU | Power Steering ECU | Destination Package 1 and 2 signal | CAN |
| Power Steering ECU | ECM | EPS idle up request signal | CAN |
| Power Steering ECU | Air Conditioning ECU | Loading control level signal | CAN |
| Power Steering ECU | Combination Meter | EPS light on request signal EPS diagnostic information signal | CAN |
| Power Steering ECU | Skid Control ECU | EPS cooperative control permission signal EPS Fail | CAN |
FREEZE FRAME DATA [03/2012 - ]
- FREEZE FRAME DATA NOTE: Freeze frame data values will vary depending on the measurement conditions, surroundings, or vehicle conditions. For this reason, there may be a problem even when the values are within specifications. Turn the engine switch on (IG) and park the vehicle on level ground. Check the freeze frame data by using the Techstream. Turn the engine switch off. Connect the Techstream to the DLC3. Turn the engine switch on (IG). Turn the Techstream on. Check the freeze frame data on the Techstream. EMPS Tester Display Measurement/Range Inspection Condition Reference Value Meter Vehicle Velocity Vehicle speed from meter/ Min.: 0 km/h (0 mph) Max.: 300 km/h (186.4 mph) The vehicle is stopped. 0 km/h (0 mph) The vehicle is driven at a constant speed. No significant fluctuation Engine Revolution Engine speed/ Min.: 0 rpm Max.: 12800 rpm The engine is running at a constant speed. No significant fluctuation Motor Actual Current Amount of current to motor/ Min.: -327.68 A Max.: 327.67 A The engine is running and steering wheel is being turned. Value changes in proportion to steering effort Command Value Current Demanded amount of current to motor/ Min.: -327.68 A Max.: 327.67 A The engine is running and steering wheel is being turned. Value changes in proportion to steering effort Steering Angle Velocity Steering angle speed/ Min.: -32768 deg/s Max.: 32767 deg/s The engine is running and steering wheel is being turned. Value changes in proportion to steering effort Thermistor Temperature ECU substrate temperature/ Min.: -50°C (-58°F) Max.: 150°C (302°F) Engine switch on (IG) - PIG Power Supply Power source voltage to activate motor/ Min.: 0 V Max.: 20.1531 V The engine is running and power steering is operating. 11 to 14 V IG Power Supply ECU power source voltage/ Min.: 0 V Max.: 20.1531 V Engine switch on (IG) 11 to 14 V Steering Wheel Torque Steering wheel torque/ Min.: -327.68 Nm Max.: 7.0 Nm The engine is running and steering wheel is being turned. Value changes in proportion to steering effort Motor Rotation Angle Motor rotation angle/ Min.: 0 deg Max.: 360 deg The engine is running and steering wheel is being turned. During steering operation, motor rotation angle value changes from 0 to 360° Command Val Current 2 Amount of current demanded by motor 2/ Min.: -327.68 A Max.: 327.67 A The engine is running and steering wheel is being turned. Value changes in proportion to steering effort PIG2 Voltage Coil rear pressurization voltage/ Min.: 0 V Max.: 98.000 V The engine is running and steering wheel is not being turned. Approximately 35 V The engine is running and steering wheel is being turned. Value changes within 16 to 46 V range Motor Voltage Motor power supply voltage/ Min.: 0 V Max.: 98.000 V The engine is running and steering wheel is not being turned. Approximately 35 V The engine is running and steering wheel is being turned. Value changes within 4 to 46 V range Motor Terminal Volt(U) Motor terminal voltage (U phase)/ Min.: 0 V Max.: 98.000 V The engine is running and steering wheel is being turned. Value changes within 4 to 46 V range Motor Terminal Volt(V) Motor terminal voltage (V phase)/ Min.: 0 V Max.: 98.000 V The engine is running and steering wheel is being turned. Value changes within 4 to 46 V range Motor Terminal Volt(W) Motor terminal voltage (W phase)/ Min.: 0 V Max.: 98.000 V The engine is running and steering wheel is being turned. Value changes within 4 to 46 V range Torque Sensor 1 Output Torque sensor 1 output value/ Min.: 0 V Max.: 5 V The engine is running and steering wheel is not turned (without load). 2.3 to 2.7 V The engine is running and steering wheel is turned to right with vehicle stopped. 2.5 to 3.8 V The engine is running and steering wheel is turned to left with vehicle stopped. 1.2 to 2.5 V Torque Sensor 2 Output Torque sensor 2 output value/ Min.: 0 V Max.: 5 V The engine is running and steering wheel is not turned (without load). 2.3 to 2.7 V The engine is running and steering wheel is turned to right with vehicle stopped. 1.2 to 2.5 V The engine is running and steering wheel is turned to left with vehicle stopped. 2.5 to 3.8 V TRQ1 Zero Point Value Zero point value of torque sensor 1/ Min.: 0 V Max.: 5 V The engine is running and steering wheel is not being turned. Values differ depending on vehicle TRQ2 Zero Point Value Zero point value of torque sensor 2/ Min.: 0 V Max.: 5 V The engine is running and steering wheel is not being turned. Values differ depending on vehicle
FAIL-SAFE CHART [03/2012 - ]
If a problem occurs in the power steering system, the P/S warning light will come on in the combination meter and the power steering assist will be stopped, locked at a particular point, or decreased simultaneously to protect the system.
| DTC No. | Detection Condition | Fail-safe |
|---|---|---|
| C1511 | Torque sensor malfunction | Power assist stops |
| C1512 | ||
| C1513 | ||
| C1514 | ||
| C1515 | ||
| C1516 | ||
| C1517 | ||
| C1521 | Motor circuit malfunction | |
| C1522 | ||
| C1523 | ||
| C1524 | ||
| C1525 | Motor rotation angle sensor malfunction | |
| C1526 | ||
| C1528 | ||
| C1531 | ECU malfunction | |
| C1532 | ||
| C1533 | Assist force restricted | |
| C1534 | ||
| C1541 | Vehicle speed signal malfunction | Amount of power assist is locked at 100 km/h (62 mph) level of power assist |
| C1551 | IG power source voltage error | Power assist stops |
| C1552 | PIG power source voltage error | |
| C1554 | Power source relay malfunction | |
| C1555 | Motor relay malfunction | |
| C1581 | Assist map not written in power steering ECU | Controlled using default map |
| C1582 | Assist map mismatch written in power steering ECU | Controlled using current default map |
| U0100 | ECM communication error | Power assist control continues normally.*1 |
| Power assist stops.*2 | ||
| U0129 | Skid control ECU communication error | Amount of power assist is locked at 100 km/h (62 mph) level of power assist |
| U1104 | Driving Support ECU communication error | Power assist control normally (Lane keeping assist system does not operate) |
POWER STEERING SYSTEM
HINT
- *1: A DTC is output while the engine is running.
- *2: A DTC is output before the engine is started.
- 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.
- If the battery is not sufficiently charged or the voltage decreases temporarily, the amount of power assist will be reduced and the P/S warning light will come on. In such cases, the amount of power assist returns normal when the battery voltage recovers.