Canada - Steering - VSC Calibration Procedure
Bulletin
0605
Issue Date
2003-08-26
Market
Canada
Reference
SR-03-001
Model
LX470
Year Range
2003
Component
SR
Subject:
VARIABLE GEAR RATIO STEERING (VGRS) CALIBRATION PROCEDURE
The purpose of this Technical Service Information Bulletin is to provide the Variable Gear Ratio Steering (VGRS) system calibration procedure. This procedure should be used after servicing the following parts:
- Steering Wheel
- Steering Column
- Steering Intermediate Shaft Assembly
- Steering Control Computer
Additionally, this procedure should be used if the steering wheel is still off-center after performing the VGRS system initialization. Please read the entire Bulletin carefully before proceeding with the calibration procedure.
APPLICABLE VEHICLES: 2003 model year LX 470 vehicles.
REPAIR PROCEDURE:
1. VGRS System Calibration Procedure.
NOTE:
This procedure should be used when the vehicle goes straight on a flat road and the steering wheel is still off-center after completing the VGRS initialization procedure in TSB 0562 titled "Pre-Delivery Service Procedures". If the vehicle has a pull condition, follow the vehicle pulling diagnosis procedure on ETAS in the Suspension and Axle: Troubleshooting section of the 2003 LX 470 Repair Manual. The pull condition must be corrected before the final centering of the steering wheel.
If the Diagnostic Tester is on, turn off the diagnostic tester. Road test the vehicle on a straight and level road. Note the steering wheel position when the vehicle is travelling straight. Find a parking lot or other low traffic area and while driving slowly, set the steering wheel to the position noted while driving straight. Stop the vehicle in a safe place and make sure the ground is flat and level. Confirm the front wheels are pointed straight ahead with the steering wheel noted in the (off center) position. Put the vehicle in Park and turn the ignition switch OFF. Turn the ignition switch back to the ON position, but DO NOT start the engine (Ignition switch ON, Engine OFF).
2. Check for VGRS DTCs (Use Lexus diagnostic tester)
Are there any DTCs set?
If YES - go to Step 3.
If NO - go to Step 4.
3. Determine if VGRS Steering Angle Adjustment Can Be Performed With The DTC.
Are DTC C1515, C1516, C1532 and /or C1568 set?
If YES - go to Step5.
If NO - Diagnose and repair vehicle according to the Repair Manual procedure.
4. Confirm VGRS System is Initialized
A. Insert the program card (version 10.0a or higher) into the hand held tester.
B. Access the VGRS data list.
C. Check the STRAIGHT ANG FLG parameter. Is the STRAIGHT ANG FLG parameter set to VALID?
If YES - VGRS System is initialized. Proceed to Step 5.
If NO - Perform VGRS System initialization procedure (See TSB 0562 Pre-Delivery Service Procedures).
NOTE:
- Prior to initialization, the STRAIGHT ANG FLG parameter will read INVALID. When the VGRS Initialization Procedure is complete, the STRAIGHT ANG FLG parameter will change to VALID.
- Use program card version 10.0a or later.
5. Steering Angle Adjustment
A. Select [5: STEER ANGLE ADJ] from the [DIAGNOSTIC MENU VGRS] menu.
B. Press [ENTER] to continue from the [NOTICE] screen.
C. Press [ENTER] to continue from the [NOTICE] screen.
D. From the [STEERING ANGLE ADJ] screen, you are ready to start the centering process. When you press [YES] the actuator lock will be set free and you will be able to center the steering wheel without turning the front wheels. Press [ENTER] to continue.
NOTE:
Rotating the steering wheel could damage the spiral cable. Do not move the steering wheel more than necessary to set the steering wheel in the straight ahead position.
E. When the [STEERING ANGLE ADJ] screen appears, turn the steering wheel to the straight and neutral position.
When the steering wheel is straight and level, press [ENTER] to continue.
F. When complete, press [ENTER] to continue from the [NOTICE] screen.
NOTE:
Wait at least 3 seconds.
G. After the Diagnostic Tester Initializes, this [NOTICE] screen will appear.
a) Move the steering wheel right and left approximately 5 degrees in each direction several times while the engine is off. The purpose of this movement is to engage the lock pawl in the actuator.
b) Make sure the steering wheel is straight before continuing and confirm the steering wheel is locked to the steering shaft (front tires move with small steering wheel input).
NOTE:
If you fail to perform this step, DTC C1568 (Lock Holder Deviation Detection) eventually will be set (it may take several hundred miles depending on driving conditions).
H. Confirm all 3 items and then press [ENTER] to continue.
I. The [ACTUATOR ANGLE ADJUSTMENT] will appear, a 5 second counter will run on the screen and the VGRS light will flash.
J. When the adjustment is completed, the [COMPLETED] screen will appear. Confirm that the VGRS warning light is off, and press [ENTER].
K. Perform the Actuator Sensor Learning Confirmation Procedure:
a) Start engine.
b) Turn steering wheel to the left 90°
c) Turn steering wheel to the right 90°
d) Center the steering wheel.
e) Hold steering wheel centered for 3 seconds.
f) Perform check procedure:
i. Turn steering wheel slowly to the left.
ii. While turning steering wheel to the left, turn the engine OFF.
iii. Continue to turn steering wheel to the left for 3 seconds after engine OFF.
g) Repeat steps (A) - (F) 15 times. C1568 will indicate if a problem occurred during the Actuator Angle Adjustment. Since C1568 requires 5 consecutive faults for this mode to set, the confirmation procedure must be performed multiple times to ensure that there is no problem.
L. Check for DTC
a) If C1568 is set, perform the VGRS System Calibration (step 4-7) procedure for a second time. If C1568 is set again, replace the VGRS actuator. (If replacing the actuator, the VGRS System Calibration must be performed again after replacement).
b) If no codes are set, the calibration procedure is complete.
6. Perform VGRS System initialization. (TSB 0562).
7. Road Test Vehicle
Road test the vehicle to confirm that the steering wheel is centered when the vehicle is travelling straight on a level road.
If YES (no problem) - finished.
If NO (problem) - return to step 1 in this Bulletin.
NOTE:
Issue of this Technical Service Bulletin is to ensure that proper repair information is available. IT DOES NOT CONSTITUTE AN AUTHORIZATION FOR REPAIR. Normal provisions of the formal warranty policy, as applicable, will apply.