Code No. C1781
SAS internal fail
| caution |
- Whenever the ECU is replaced, ensure
that the CAN bus lines are normal.
- When the steering wheel sensor is replaced, calibrate the steering wheel sensor
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OPERATION
FCM/LDW/AHB-ECU communicates with the steering wheel sensor via the
CAN bus lines.
DIAGNOSIS CODE SET CONDITION
This diagnosis code is set when the abnormality below is detected:
- The ECU receives a signal which indicates an internal error in the steering
wheel sensor.
PROBABLE CAUSES
- The steering wheel sensor has not been calibrated correctly.
- Malfunction of the steering wheel sensor (column switch assembly)
- Malfunction of the FCM/LDW/AHB-ECU
DIAGNOSIS PROCEDURE
STEP 1. Check whether the steering wheel sensor is installed
properly.
Q.
Is the check result normal?
Go to Step 2.
Install the steering wheel sensor properly.
STEP 2. M.U.T.-III data list.
Check the input signal.
- Vehicle stopped (the steering wheel is in the neutral position)
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Item No.
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Item name
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Normal condition
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17
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Steering wheel angle
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-6 to 6 deg
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Item No.
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Item name
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Normal condition
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17
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Steering wheel angle
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Nearly the same as the steering wheel operation angle (-750 to 750
deg)
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OK: Normal condition is displayed.
Q.
Is the check result normal?
Go to Step 3.
Replace the steering wheel sensor (column switch assembly) (Refer to GROUP 54A - Column
Switch 
).
STEP 3. Check whether the diagnosis code is set again.
Check again if the diagnosis code is set in the FCM/LDW/AHB-ECU.
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(1)Erase the diagnosis code.
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(2)Turn the ignition switch from "LOCK" (OFF) position to "ON" position.
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(3)Check if diagnosis code is set.
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Q.
Is the diagnosis code set?
Replace the FCM/LDW/AHB-ECU (Refer to ).
The trouble can be an intermittent malfunction (Refer to GROUP 00 - How
to use Troubleshooting/inspection Service Points - How to Cope with Intermittent Malfunction).