Code No. U0428: SAS (CAN message)
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 - Troubleshooting
).
- 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 ASTC-ECU learn the neutral point (Refer to
).
- When the hydraulic unit assembly (integrated with ASTC-ECU) is replaced, always carry out the calibration of the steering wheel sensor and the G sensor (Refer to
).
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OPERATION
The steering wheel sensor outputs the steering wheel status to ASTC-ECU via the CAN bus lines.
DIAGNOSIS CODE SET CONDITIONS
This diagnosis code is set when ASTC-ECU has detected the communication error in the steering wheel sensor.
PROBABLE CAUSES
Current trouble
- Malfunction of the column switch assembly (Integrated with steering wheel sensor)
- Malfunction of the hydraulic unit assembly (integrated with ASTC-ECU)
- Noise interference
Past trouble
- Carry out diagnosis with particular emphasis on wiring harness and connector failures between ASTC-ECU and the steering wheel sensor. For diagnosis procedures, refer to How to treat past trouble (GROUP 00 - How to Cope with Intermittent Malfunctions
).
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STEP 1. M.U.T.-III CAN bus diagnosis
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Use the M.U.T.-III to diagnose the CAN bus lines.
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Q.
Is the check result normal?
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Go to Step 3.
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Repair the CAN bus lines (Refer to GROUP 54C - Troubleshooting ). On completion, go to Step 2.
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STEP 2. Diagnosis code recheck after resetting CAN bus lines
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Q.
Is diagnosis code No. U0428 set?
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Go to Step 3.
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This diagnosis is complete.
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STEP 3. Check for diagnosis codes of other systems.
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Check if diagnosis code(s) other than U0428 is set.
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Q.
Is the diagnosis code set?
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Follow the relevant diagnosis code procedure, and then go to Step 5.
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Go to Step 4.
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STEP 4. Diagnosis code recheck
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Check again if the diagnosis code is set.
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(1)Erase the set diagnosis code.
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(2)Ignition switch: "LOCK" (OFF)
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Q.
Is diagnosis code No. U0428 set?
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Replace the column switch assembly (Integrated with steering wheel sensor) (Refer to GROUP 54A - Column Switch ). Then go to Step 5.
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The trouble can be an intermittent malfunction (Refer to GROUP 00 - How to Cope with Intermittent Malfunction ).
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STEP 5. Diagnosis code recheck
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Check again if the diagnosis code is set.
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(1)Erase the set diagnosis code.
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(2)Ignition switch: "LOCK" (OFF)
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Q.
Is diagnosis code No. U0428 set?
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Replace the hydraulic unit assembly (integrated with ASTC-ECU) (Refer to ).
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The trouble can be an intermittent malfunction (Refer to GROUP 00 - How to Cope with Intermittent Malfunction ).
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