Code No.U1073: Bus Off
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If diagnosis code U1073 is set in the SRS-ECU, diagnose the CAN main bus line.
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Whenever the ECU is replaced, ensure that the input and output signal circuits are normal.
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DIAGNOSIS CODE SET CONDITIONS
Diagnosis code No.U1073 will be stored when the SRS-ECU ceases CAN communication (bus off) and then resumes the communication by turning the ignition switch to the "LOCK" (OFF) position. However, if the system returns to normal condition, the warning lamp will be go out. (The diagnosis code is not erased.)
TROUBLE CAUSES
The wiring harness wire or connectors may have loose, corroded, or damage terminals, or terminals pushed back in the connector, or the SRS-ECU may be defective.
PROBABLE CAUSES
- Defective connector(s) or wiring harness
- Malfunction of the SRS-ECU
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STEP 1. M.U.T.-III CAN bus diagnostics
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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 2 .
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 Repair the CAN bus line (Refer to GROUP 54F, Diagnosis  ).
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STEP 2. Check whether the diagnosis code is reset.
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Check again if the diagnosis code is set.
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(1)Erase the diagnosis code.
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(2)Ignition: LOCK (OFF) position to ON
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(3)On completion, check that the diagnosis code is not reset.
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Q.
Is the check result satisfactory?
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There is an intermittent malfunction such as poor engaged connector(s) or open circuit (Refer to GROUP 00, How to Use Troubleshooting/Inspection Service Points .)
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Replace the SRS-ECU. On completion, check that the diagnosis code is not reset.
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