If diagnosis code No. U0019 is set, be sure to diagnose the CAN bus line.
When replacing the ECU, always check that the communication circuit is normal.
DIAGNOSTIC FUNCTION
If the CAN-B circuit malfunction occurs, SRS-ECU sets the diagnosis code No. U0019.
JUDGEMENT CRITERIA
Because of the CAN-B bus circuit malfunction, if SRS-ECU becomes unable to perform the normal data transmission, SRS-ECU determines that an abnormality is present.
PROBABLE CAUSES
Malfunction of CAN bus line
DIAGNOSIS PROCEDURE
STEP 1. Check whether the diagnosis code is reset..
(1)Connect the negative battery terminal.
(2)After erasing the diagnosis code memory, check the diagnosis code again.
(3)Disconnect the negative battery terminal.
Q.
Is the diagnosis code No. U0019 set?
Go to Step 2.
Intermittent malfunction (Refer to GROUP 00 - How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunction ).
STEP 2. M.U.T.-III CAN bus diagnostics.
Use M.U.T.-III to diagnose the CAN bus lines.
Q.
Is the check result normal?
Intermittent malfunction (Refer to GROUP 00 - How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunction ).
Repair the CAN bus line (Refer to GROUP 54C - Troubleshooting ).
Intermittent malfunction (Refer to GROUP 00 - How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunction 
).