Variable Gear Ratio Steering (Diagnostics - Introduction): Other Lexus LX J200

PRECAUTION

1. TROUBLESHOOTING PRECAUTIONS If the problem is caused by a poor connection of a terminal or poor installation of a part, reconnecting the terminal, or removing and reinstalling the part may solve the problem, or may temporarily return the system to normal. To determine the cause of the problem, check for DTCs or confirm the vehicle operating conditions when the problem occurred and note them down before disconnecting connectors or removing parts. Be sure to check for DTCs in other systems as the problem may be caused by a malfunction in another system. DTCs may be stored in the vehicle stability control system due to Variable Gear Ratio Steering (VGRS) system inspections. Check for DTCs in the vehicle stability control system and clear any output codes after inspecting the VGRS system. When the engine switch is turned on (IG)/off, the system start-up/stop operation is performed. At this time, a small operating sound can be heard and the steering wheel turns slightly. If "Invalid" is displayed for "Straight Angle Valid Flag" in the Data List, the VGRS system does not operate. If the steering wheel is turned left and right with the engine switch off, a noise can be heard. However, this is not a malfunction.
2. HANDLING AND OPERATING PRECAUTIONS Removal and installation of the steering control ECU, steering actuator, and each sensor must be performed with the engine switch off unless specified. If the steering control ECU, steering actuator, or a sensor is removed and installed, perform the test mode inspection, check for DTCs, and confirm that the normal system code is output. If the engine switch is turned on (IG) with the steering control ECU connector disconnected, DTCs may be stored in the vehicle stability control system. Check for DTCs in those systems and clear any output codes after completing repairs.
3. PRECAUTIONS FOR REPLACEMENT OF STEERING SYSTEM PARTS If the steering control ECU or steering actuator is replaced, perform actuator angle neutral point calibration and initialization. The steering control ECU cannot be disassembled or repaired. If there is any problem with the steering control ECU, replace it with a new one.
4. PRECAUTIONS FOR STEERING WHEEL OFF-CENTER NOTE: If the steering wheel is still off-center after completing steering angle sensor initialization. Refer to «INITIALIZATION»(ref-385244-S17081646282011021400000) , perform VGRS system calibration. Refer to «CALIBRATION»(ref-385244-S03519815142011021400000) . HINT: The steering wheel may become off-center under any of the following conditions. These conditions do not indicate a malfunction. The steering wheel is turned when the engine switch is off. The steering wheel is turned quickly. The steering wheel is turned to the left or right lock position. If the steering wheel is off-center, drive the vehicle at 35 km/h (22 mph) or more for 5 seconds or more, or turn the steering wheel to the left and right with the vehicle stopped or while driving at low speeds. This may center the steering wheel. If one of the situations under "Conditions Under Which VGRS System Does Not Operate" occurs, the steering wheel may temporarily become off-centered.
5. CONDITIONS UNDER WHICH VGRS SYSTEM DOES NOT OPERATE The VGRS system does not operate under any of the following conditions: The power supply voltage is low or too high. A fail-safe function is operating to protect the system from overheating. System control is suspended to prevent the motor in the steering actuator and the steering control ECU from overheating. If the temperatures of the motor and ECU drop, the system will return to normal. The vehicle is exposed to extremely low temperatures. If the ambient temperature becomes approximately -30°C (-22°F), system control will be suspended. NOTE: If any of the above occurs, perform steering angle sensor initialization. Refer to «INITIALIZATION»(ref-385244-S17081646282011021400000) .

Scheme 11

Scheme 12

Scheme 13

FREEZE FRAME DATA

HINT

The VGRS system stores data when a trouble code is stored which can be viewed using the Techstream.

1. FREEZE FRAME DATA OF STEERING CONTROL ECU Connect the Techstream to the DLC3. Turn the engine switch on (IG) and check the freeze frame data by following the prompts on the Techstream screen. VGRS Tester Display Measurement Item/Range Normal Condition Diagnostic Note Vehicle Speed (Vsc ECU) Vehicle speed (Skid control ECU)/ Min.: 0 km/h (0 mph), Max.: 255 km/h (158 mph) Actual vehicle speed (Speed indicated on speedometer) - Engine ReVolution (Rpm) Engine speed (rpm)/ Less than 300 or 300 or more Engine stopped: Less than 300 rpm Engine running: 300 rpm or more - Mtr Power Source Cur. Motor power source actual current/ Min.: 0 A, Max.: 127.5 A Steering wheel not turned: Below 1 A Steering wheel turned: 1 A or higher - PIG-Power Source Volt PIG power source voltage/ Min.: 0 V, Max.: 25.5 V Engine switch on (IG): 11 to 14 V - IG-Power Source Volt IG power source voltage/ Min.: 0 V, Max.: 25.5 V Engine switch on (IG): 11 to 14 V - Lock Motor Output Volt Lock motor output voltage/ Min.: 0 V, Max.: 25.5 V Engine switch on (IG): 11 to 14 V - Command Value Duty Command duty value for PVM control/ Min.: 0%, Max.: 100% VGRS system operating: 0 to 100% VGRS system not operating: 0% - Actuator Lock Duty Val Command duty value for actuator lock control/ Min.: 0%, Max.: 100% Engine switch on (IG): Below 10% - Resolver Offset(SIN) Resolver offset (SIN)/ Min.: 0, V Max.: 25.5 V Steering wheel turned: 0 to 16 V Steering wheel not turned: 0 V - Resolver Offset(COS) Resolver offset (COS)/ Min.: 0, V Max.: 25.5 V Steering wheel turned: 0 to 16 V Steering wheel not turned: 0 V - Motor Current U Motor current U/ Min.: -63 A, Max.: 64.5 A Steering wheel turned: 0 to 64.5 A Steering wheel not turned: 0 A - Motor Current V Motor current V/ Min.: -63 A, Max.: 64.5 A Steering wheel turned: 0 to 64.5 A Steering wheel not turned: 0 A - Motor Current W Motor current W/ Min.: -63 A, Max.: 64.5 A Steering wheel turned: 0 to 64.5 A Steering wheel not turned: 0 A - Motor Voltage Motor voltage/ Min.: 0 V, Max.: 51 V VGRS system operating: 9 to 36 V VGRS system not operating: 0 V - Steering Pos 1 Steering position/ Min.: -2047 deg., Max.: 2048.94 deg. Steering wheel turned to right: Display value changes in negative direction Steering wheel turned to left: Display value changes in positive direction - Actuator Position Actuator position/ Min.: -2047 deg., Max.: 2048.94 deg. Steering wheel turned: -2047 to 2048.94 deg. - Steering Angle Velocity Steering angle velocity/ Min.: -2047 deg./s, Max.: 2048.94 deg./s Steering wheel turned to right: Display value changes in negative direction Steering wheel turned to left: Display value changes in positive direction - Actuator Target Angle 1 Actuator target angle 1/ Min.: -2047 deg., Max.: 2048.94 deg. Steering wheel turned: -2047 to 2048.94 deg. - Actuator Target Angle 2 Actuator target angle 2/ Min.: -2047 deg., Max.: 2048.94 deg. Steering wheel turned: -2047 to 2048.94 deg. - Actuator ReVolution Spd Actuator revolution speed/ Min.: -2047 deg./s, Max.: 2048.94 deg./s Steering wheel turned to right: Display value changes in negative direction Steering wheel turned to left: Display value changes in positive direction - Mode State Mode state/ 00, 01, 02, 03, 04, 05, 06, 07, 08, 09, 0A, 0B, 0C, 0D, 0E, 0F or 10