Code No. C1555 Output error in steering wheel sensor

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.

OPERATION

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

DIAGNOSIS CODE SET CONDITIONS

When an abnormality (larger than the actual maximum steering angle) is detected in the steering angle, the diagnosis is set.

PROBABLE CAUSES

Malfunction of the steering wheel sensor
Steering wheel sensor improper installation
Steering wheel sensor calibration error
Malfunction of ASC-ECU

DIAGNOSIS PROCEDURE

STEP 1. M.U.T.-III CAN bus diagnostics

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 the diagnosis code No.C1555 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.

Q. Is the check result normal?

	Go to Step 4.

	Install the steering wheel sensor correctly (Refer to ). Then go to Step 4.

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 shows the deviation within ±5° from the neutral position (Refer to

Item No.16: Steering angle

Q. Is the check result normal?

	Go to Step 5.

	Perform calibration of steering wheel sensor (Refer to ).

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.16: Steering angle

Q. Is the check result normal?

	Go to Step 6.

	After the steering wheel sensor is replaced, perform the steering wheel sensor calibration (Refer to ).

STEP 6. Diagnosis code recheck

(1)Erase the diagnosis code.

(2)Turn the electric motor switch from "LOCK" (OFF) position to "ON" position.

Q. Is the diagnosis code No.C1555 set?

	Replace the hydraulic unit (integrated with ASC-ECU) (Refer to ). Then go to Step 7.

	Intermittent malfunction (Refer to GROUP 00 - How to Use Troubleshooting/How to Cope with Intermittent Malfunctions ).

STEP 7. Diagnosis code recheck

(1)Erase the diagnosis code.

(2)Turn the electric motor switch from "LOCK" (OFF) position to "ON" position.

Q. Is the diagnosis code No.C1555 set?

	Return to Step 1.

	This diagnosis is complete.