Code No. C1505: Steering wheel sensor (signal seizure or abnormal neutral point)
Code No. C1506: Steering wheel sensor (steering wheel sensor malfunction)


caution
  • 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 hydraulic unit (integrated with ASTC-ECU) is replaced, always carry out the calibration of the steering wheel sensor and the G and yaw rate sensor (Refer to ).

OPERATION


The steering wheel sensor output signal is sent to ASTC-ECU via the CAN bus lines.

DIAGNOSIS CODE SET CONDITIONS


When an abnormal signal is output from the steering wheel sensor, the ASTC-ECU determines that the trouble occurs and sets the diagnosis code.

PROBABLE CAUSES



DIAGNOSIS PROCEDURE

STEP 1. M.U.T.-III CAN bus diagnosis
Use the 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. C1505 or C1506 set?
Go to Step 3.
This diagnosis is complete.

STEP 3. Steering wheel sensor installation state check
Check that the steering wheel sensor is installed correctly (Refer to ).

Q. Is the check result normal?
Go to Step 4.
Install the steering wheel sensor correctly. (Refer to .) Then go to Step 8.

STEP 4. M.U.T.-III data list
With the front wheel facing in the straight-ahead direction, check the steering wheel sensor signal using the data list. Check that the data list deviates within ±5° from the neutral position (Refer to ).

  • Item No.03: Steering angle
  • Item No.21: Steering angle (Raw value)

Q. Is the check result normal?
Go to Step 5.
Calibrate the steering wheel sensor (Refer to ). Then go to Step 8.

STEP 5. M.U.T.-III data list
Turn the steering wheel fully to the left, and then turn it fully to the right. Then check that the value of the steering wheel sensor changes smoothly using the data list. In addition, check that the steering wheel angle on the data list almost matches the actual steering wheel angle (Refer to ).

  • Item No.03: Steering angle
  • Item No.21: Steering angle (Raw value)

Q. Is the check result normal?
Go to Step 7.
Go to Step 6.

STEP 6. Check whether the diagnosis code is set again.
Check again if the diagnosis code is set.
(1)Start the engine.
(2)Drive the vehicle at 35 km/h or more for at least one second with the steering wheel at the neutral position. Then turn it to the right and left.
(3)Erase the diagnosis code.
(4)Turn the ignition switch to the "LOCK" (OFF) position.
(5)Turn the ignition switch to the "ON" position.
(6)Check if the diagnosis code is set.

Q. Is diagnosis code No. C1505 or C1506 set?
Replace the steering wheel sensor (Refer to ). Then go to Step 7.
The trouble can be an intermittent malfunction (Refer to GROUP 00 - How to Cope with Intermittent Malfunction ).

STEP 7. Check whether the diagnosis code is set again.
Check again if the diagnosis code is set.
(1)Start the engine.
(2)Drive the vehicle at 35 km/h or more for at least one second with the steering wheel at the neutral position. Then turn it to the right and left.
(3)Erase the diagnosis code.
(4)Turn the ignition switch to the "LOCK" (OFF) position.
(5)Turn the ignition switch to the "ON" position.
(6)Check if the diagnosis code is set.

Q. Is diagnosis code No. C1505 or C1506 set?
Replace the hydraulic unit assembly (integrated with ASTC-ECU) (Refer to ). Then go to Step 8.
The trouble can be an intermittent malfunction (Refer to GROUP 00 - How to Cope with Intermittent Malfunction ).

STEP 8. Check whether the diagnosis code is set again.
Check again if the diagnosis code is set.
(1)Start the engine.
(2)Drive the vehicle at 35 km/h or more for at least one second with the steering wheel at the neutral position. Then turn it to the right and left.
(3)Erase the diagnosis code.
(4)Turn the ignition switch to the "LOCK" (OFF) position.
(5)Turn the ignition switch to the "ON" position.
(6)Check if the diagnosis code is set.

Q. Is diagnosis code No. C1505 or C1506 set?
Return to Step 1.
The procedure is complete.