Code No. U0100 Engine CAN timeout


caution
  • If diagnosis code No.U0100 is set in the SRS-ECU, diagnose the CAN main bus line.
  • Whenever the ECU is replaced, ensure that the input and output signal circuits are normal.

TROUBLE JUDGEMENT


If signal from the engine-ECU cannot be received for 500 milliseconds or more, the SRS-ECU sets diagnosis code No. U0100.

PROBABLE CAUSES



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 2
Repair the CAN bus line (Refer to GROUP 54C - Troubleshooting ). On completion, go to Step 6.

STEP 2. Check the M.U.T.-III Diagnosis code for other systems
Check that the engine-ECU set a diagnosis code.

Q. Is the diagnosis code set?
Diagnose the engine-ECU. Refer to GROUP 13A, Troubleshooting .
Go to Step 3

STEP 3. Check the M.U.T.-III Diagnosis code for other systems
Check if the diagnosis code No. U0100 is set to ETACS-ECU.

Q. Is the diagnosis code set?
Go to Step 4
Go to Step 5

STEP 4. Check whether the diagnosis code is reset.
Check again if the diagnosis code is set to the SRS-ECU.
(1)Erase the diagnosis code.
(2)Turn the ignition switch from "LOCK" (OFF) position to "ON" position.
(3)On completion, check that the diagnosis code is reset.

Q. Is the diagnosis code set?
Replace the engine-ECU. After replacing the ECU, carry out the CAN bus diagnostics. Then go to Step 6.
A poor connection, open circuit or other intermittent malfunction is present in the CAN bus lines between the engine-ECU and the SRS-ECU (Refer to GROUP 00, How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunctions ).

STEP 5. Check whether the diagnosis code is reset.
Check again if the diagnosis code is set to the SRS-ECU.
(1)Erase the diagnosis code.
(2)Turn the ignition switch from "LOCK" (OFF) position to "ON" position.
(3)On completion, check that the diagnosis code is not reset.

Q. Is the diagnosis code set?
Replace the SRS-ECU. After replacing the ECU, carry out the CAN bus diagnostics. Then go to Step 6.
A poor connection, open circuit or other intermittent malfunction is present in the CAN bus lines between the engine-ECU and the SRS-ECU (Refer to GROUP 00, How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunctions ).

STEP 6. Check whether the diagnosis code is reset.
Recheck if the diagnosis code is set to the SRS-ECU.
(1)Erase the diagnosis code.
(2)Turn the ignition switch from "LOCK" (OFF) position to "ON" position.
(3)On completion, check that the diagnosis code is reset.

Q. Is the diagnosis code set?
Return to Step 1.
The procedure is complete.