Variable Gear Ration Steering System (Diagnostics - Introduction): Diagnosis Lexus GS III facelift

HOW TO PROCEED WITH TROUBLESHOOTING

HINT

*: Use the Techstream.

1. VEHICLE BROUGHT TO WORKSHOP NEXT: Go to next step
2. CUSTOMER PROBLEM ANALYSIS Confirm problem symptoms. NEXT: Go to next step
3. CHECK MULTIPLEX COMMUNICATION SYSTEM* Check for DTCs. DTC is not output. A DTC is output. B B --> GO TO MULTIPLEX COMMUNICATION SYSTEM A: Go to next step
4. CHECK CAN COMMUNICATION SYSTEM* Check for DTCs. DTC is not output. A DTC is output. B B --> GO TO CAN COMMUNICATION SYSTEM A: Go to next step
5. CHECK DTC* Check for DTCs. Record the DTCs. Clear the DTCs. Recheck for DTCs. Simulate the malfunction and check if the DTCs are output again. Refer to «DTC CHECK / CLEAR»(ref-382810-S16608627522011012800000) . DTC is output. A DTC is not output. B DTCs are not output, and the malfunction can not be simulated or checked. C B --> GO TO STEP 10 C --> SYMPTOM SIMULATION A: Go to next step
6. DTC CHART NEXT: Go to next step
7. CIRCUIT INSPECTION* NEXT: Go to next step
8. REPAIR NEXT: Go to next step
9. CONFIRMATION TEST NEXT --> END
10. PROBLEM SYMPTOMS TABLE NEXT: Go to next step
11. CIRCUIT INSPECTION* NEXT: Go to next step
12. CONFIRMATION TEST NEXT --> END

Scheme 13

1. STEERING ANGLE SENSOR INITIALIZATION (to obtain a tire angle (during straight-ahead driving) signal) Turn the engine switch on (IG), and check that the master warning light and VSC/ABS warning lights illuminate for a few seconds. NOTE: If the warning lights remain on or blink, repair he applicable system. Drive the vehicle on a straight road at 35 km/h (22 mph) or more for 5 seconds or longer. HINT: At this point, the steering wheel will still remain off-center by 5 to 10 degrees. In this step, the neutral position of the steering wheel is restored from the steering control ECU memory. Confirm that steering angle sensor initialization is completed (when using the Techstream). Enter the VGRS menu using the Techstream. Select "Straight Angle Valid Flag" from "Data List". Check if the steering angle sensor has obtained a tire angle (during straight-ahead driving) signal. Standard "Valid" is displayed on the Techstream screen. Confirm that steering angle sensor initialization is completed (when not using the Techstream). Drive the vehicle on a straight road at 60 km/h (37 mph) or more for 30 seconds or longer. Stop the vehicle (engine running). Slowly turn the steering wheel from lock to lock. If it turns approximately 2.7 turns, steering angle sensor initialization is completed. If it turns approximately 3.2 turns, steering angle sensor initialization is not completed. NOTE: If the steering wheel turns approximately 3.2 turns, perform step b again.

PROBLEM SYMPTOMS TABLE

HINT

If a normal system code is displayed during the DTC check but the problem still occurs, check the circuits for each problem symptom in the order given in the table below and proceed to the relevant troubleshooting information .

VARIABLE GEAR RATIO STEERING SYSTEM

DATA LIST / ACTIVE TEST

1. DATA LIST HINT: Using the Techstream to read the Data List allows the values or states of switches, sensors, actuators and other items to be read without removing any parts. This non-intrusive inspection can be very useful because intermittent conditions or signals may be discovered before parts or wiring is disturbed. Reading the Data List information early in troubleshooting is one way to save diagnostic time. NOTE: In the table below, the values listed under "Normal Condition" are reference values. Do not depend solely on these reference values when deciding whether a part is faulty or not. Connect the Techstream to the DLC3. Turn the engine switch on (IG). Turn the Techstream on. Enter the following menus: Chassis / VGRS / Data List. According to the display on the Techstream, read the Data List. VGRS Tester Display Measurement Item/Range Normal Condition Diagnostic Note Vehicle Speed(Vsc ECU) Vehicle speed (VSC ECU)/ Min.: 0 km/h, Max.: 255 km/h Actual vehicle speed Speed indicated on speedometer Engine Revolution(Rpm) Engine revolution (rpm)/ Less 300 or More 300 Less than 300 rpm More than 300 rpm Engine stopped Engine running Mtr Power Source Cur. Motor power source actual current/ Min.: 0 A, Max.: 127.5 A Less than 1 A More than 1 A When not turning the steering wheel When turning the steering wheel PIG-Power Source Volt PIG power source voltage/ Min.: 0 V, Max.: 25.5 V 9 to 16 V Engine switch on (IG) (Engine stopped) IG-Power Source Volt IG power source voltage/ Min.: 0 V, Max.: 25.5 V 9 to 16 V Engine switch on (IG) (Engine stopped) Terminal Voltage U Terminal voltage U/ Min.: 0 V, Max.: 25.5 V 0 to 16 V Turning the steering wheel changes the value (with the engine running and the VGRS system operating) Terminal Voltage V Terminal voltage V/ Min.: 0 V, Max.: 25.5 V 0 to 16 V Turning the steering wheel changes the value (with the engine running and the VGRS system operating) Terminal Voltage W Terminal voltage W/ Min.: 0 V, Max.: 25.5 V 0 to 16 V Turning the steering wheel changes the value (with the engine running and the VGRS system operating) Lock Motor Output Volt Lock motor output voltage/ Min.: 0 V, Max.: 25.5 V 9 to 16 V Engine switch on (IG) (Engine stopped) Thermistor Temperature Thermistor temperature/ Min.: -50°C, Max.: 205°C -50 to 150°C When the VGRS system operates Command Value Duty Command value DUTY for PVM control/ Min.: 0%, Max.: 100% 0 to 100% When the VGRS system operates Actuator Lock Duty Val Command value DUTY for actuator lock control/ Min.: 0%, Max.: 100% Less than 10% Engine switch on (IG) Straight Angle Valid Flag*1 Straight steering angle valid flag/ Valid or Inval Valid or Inval Immediately after connecting the battery terminal Actuator Estimate Temp Actuator estimation temperature/ Min.: -50°C, Max.: 205°C -50 to 150°C When the VGRS system operates Motor Overheat Record*2 Record of continuous overheat preventive control/ Rec or Unrec Rec or Unrec - Motor Lo Power Record*2 Record of low motor power source voltage/ Rec or Unrec Rec or Unrec - Motor Overload Record*2 Record of high motor power source voltage/ Rec or Unrec Rec or Unrec - The Number of DTCs The number of DTCs/ Max.: 0, Min.: 255 0 to 255 - Test Mode Status Test mode status/ Normal or Test Normal or Test - Steering Mode Absorber control switch (AVS switch) position/ Sports or Normal Absorber control switch position is SPORT: Sports Absorber control switch position is NORM: Normal - Elec Angle Position Deep-slot electric angle position recorded when actuator angle neutral point adjustment completed normally/ Min.: 0°, Max.: 360° - - Resolver Offset(SIN) Resolver offset (SIN)/ Min.: 0, V Max.: 25.5 V Steering wheel is turned: 0 to 16 V Steering wheel is not turned: 0 V - Resolver Offset(COS) Resolver offset (COS)/ Min.: 0, V Max.: 25.5 V Steering wheel is turned: 0 to 16 V Steering wheel is not turned: 0 V - Motor Current U Motor current U/ Min.: -63 A, Max.: 64.5 A Steering wheel is turned: 0 to 64.5 A Steering wheel is not turned: 0 A - Motor Current V Motor current V/ Min.: -63 A, Max.: 64.5 A Steering wheel is turned: 0 to 64.5 A Steering wheel is not turned: 0 A - Motor Current W Motor current W/ Min.: -63 A, Max.: 64.5 A Steering wheel is turned: 0 to 64.5 A Steering wheel is 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 Pos1 Steering position/ Min.: -2047 deg, Max.: 2048.94 deg Steering wheel is turned to right: Display value changes in negative direction Steering wheel is turned to left: Display value changes in positive direction - Steering Pos2 Steering position/ Min.: -49150.5 deg, Max.: 49152 deg Steering wheel is turned to right: Display value changes in negative direction Steering wheel is turned to left: Display value changes in positive direction - Actuator Position Actuator position/ Min.: -2047 deg, Max.: 2048.94 deg Steering wheel is turned: -2047 to 2048.94 deg. - Steering Angle Velocity Steering angle velocity/ Min.: -2047 deg/s, Max.: 2048.94 deg/s Steering wheel is turned to right: Display value changes in negative direction Steering wheel is turned to left: Display value changes in positive direction - Actuator Target Angle1 Actuator target angle 1/ Min.: -2047 deg, Max.: 2048.94 deg Steering wheel is turned: -2047 to 2048.94 deg - Actuator Target Angle2 Actuator target angle 2/ Min.: -2047 deg, Max.: 2048.94 deg Steering wheel is turned: -2047 to 2048.94 deg - Actuator ReVolution Spd Actuator revolution speed/ Min.: -2047 deg/s, Max.: 2048.94 deg/s Steering wheel is turned to right: Display value changes in negative direction Steering wheel is turned to left: Display value changes in positive direction - Actuator Deviation Ang Actuator deviation angle/ Min.: -32 rad, Max.: 32 rad VGRS system operating: -32 to 32 rad. - Mode State Mode State/ 01, 02, 03, 04, 06, 07, 08, 09, 0A, 0B, 0C, 0D, 0E, 0F, 10 01, 02, 03, 04, 06, 07, 08, 09, 0A, 0B, 0C, 0D, 0E, 0F, or 10 - NOTE: *1: This data must be "Valid" before proceeding with any steering adjustment. If "Inval" is displayed, perform steering angle sensor initialization procedure. Alternatively, if the steering actuator or steering control ECU has been replaced, perform VGRS system calibration (steering angle adjustment). HINT: *2: If "Rec" is displayed, enter the VGRS menu on the Techstream, select record clearance, and follow the prompts to set to "Unrec".
2. ACTIVE TEST HINT: Using the Techstream to perform Active Tests allows relays, VSVs, actuators and other items to be operated without removing any parts. This non-intrusive functional inspection can be very useful because intermittent operation may be discovered before parts or wiring is disturbed. Performing Active Tests early in troubleshooting is one way to save diagnostic time. Data List information can be displayed while performing Active Tests. Turn the engine switch off. Connect the Techstream to the DLC3. Turn the engine switch on (IG). Turn the Techstream on. Enter the following menus: Body Electrical / Combination Meter / Active Test. According to the display on the Techstream, perform the Active Test. COMBINATION METER Tester Display Test Part Control Range Diagnostic Note Master Warning Master caution indicator light Indicator light / ON or OFF Confirm that the vehicle is stopped, engine idling

DIAGNOSTIC TROUBLE CODE CHART

HINT

If a trouble code is displayed during the DTC check, check the circuit indicated by the DTC. For details of each code, proceed to the procedure for the respective "DTC No." in the following DTC chart.

VARIABLE GEAR RATIO STEERING SYSTEM