If there is
any problem in the CAN bus lines, an incorrect diagnosis code may be set. Prior to this diagnosis,
diagnose the CAN bus lines (Refer to GROUP 54C - CAN Bus Diagnostics Table ).
Whenever ECU is replaced, ensure that the CAN bus lines are normal.
When the steering wheel sensor is replaced, always carry out calibration to make
ASC-ECU learn the neutral point (Refer to ).
OPERATION
Steering wheel sensor outputs the signal to ASC-ECU via the CAN bus lines.
DIAGNOSIS CODE SET CONDITIONS
This diagnosis code is set if any malfunction below is found:
The tolerance of neutral position of steering wheel sensor exceeds the specified
range.
Abnormality in steering wheel sensor output value
When abnormality is detected by comparing the value output from the steering wheel
sensor with the one from the wheel speed sensor and the G and yaw rate sensor.
PROBABLE CAUSES
Improper installation of steering wheel sensor
Wheel alignment not performed
Steering wheel sensor malfunction
Different steering wheel
Malfunction of wheel speed sensor
ASC-ECU malfunction
External noise interference
Wrong steering wheel is attached
DIAGNOSIS PROCEDURE
STEP 1. M.U.T.-III CAN bus diagnostics
Use M.U.T.-III to diagnose the CAN bus lines.
Q.
Is the check result normal?
Go to Step 3
Repair the CAN bus lines (Refer to GROUP 54C - CAN Bus Diagnostics Table ).
On completion, go to Step 2.
STEP 2. Diagnosis code recheck after resetting CAN bus lines
Q.
Is diagnosis code No.C1219 set?
Go to Step 3
This diagnosis is complete.
STEP 3. M.U.T.-III diagnosis code
Check that the wheel speed sensor-related, G and yaw rate sensor-related, or steering
wheel sensor-related diagnosis code is set.
Q.
Is the diagnosis code set?
Troubleshoot the relevant diagnosis code, and then go to Step 8.
Go to Step 4
STEP 4. Check how steering wheel sensor is installed.
Check that the steering wheel sensor is installed correctly (Refer to ).
Q.
Is the check result normal?
Go to Step 5
Install the steering wheel sensor correctly (Refer to ),
and then go to Step 5.
STEP 5. Wheel alignment check
Q.
Is the check result normal?
After the wheel alignment check, perform the steering wheel sensor calibration
to make ASC-ECU learn the neutral point again (Refer to ).
Then go to Step 6.
After the adjustment of the wheel alignment, perform the steering wheel sensor
calibration to make ASC-ECU learn the neutral position again (Refer to ).
Then go to Step 6.
STEP 6. M.U.T.-III data list
Check the following data list (Refer to ).
Item 11: Steering angle
Q.
Is the check result normal?
Go to Step 7
After the steering wheel sensor is replaced, perform the steering wheel sensor
calibration to make ASC-ECU learn the neutral point again (Refer to ).
Then go to Step 8.
STEP 7. Check whether the diagnosis code is reset.
(1)Erase the diagnosis code.
(2)Turn the steering wheel to either right or left at 20 km/h or more.
note
The ASC warning/operation lamp and the ASC OFF lamp may remain on until the vehicle
speed reaches approx. 10 km/h, then the steering wheel is turned to either right or
left.
Q.
Is diagnosis code No.C1219 set?
Replace the hydraulic unit (integrated with ASC-ECU) (Refer to ), and
then go to Step 8.
This diagnosis is complete.
STEP 8. Check whether the diagnosis code is reset.
(1)Erase the diagnosis code.
(2)Turn the steering wheel to either right or left at 20 km/h or more.
note
The ASC warning/operation lamp and the ASC OFF lamp may remain on until the vehicle
speed reaches approx. 10 km/h, then the steering wheel is turned to either right or
left.