Code No.U1000 OSS/KOS_OSS CAN timeout <Vehicles with KOS>


caution
  • If diagnosis code No. U1000 is set, be sure to diagnose the CAN bus line.
  • When replacing the ECU, always check that the communication circuit is normal.

TROUBLE JUDGEMENT


The combination meter sets diagnosis code No.U1000 when it cannot receive signals from the KOS&OSS-ECU.

JUDGEMENT CRITERIA


With the ignition switch is at ON position, diagnosis code No. U1190 is not set and diagnosis code No. U1195 is not set, if the communication with KOS&OSS-ECU cannot be established for 2500 ms or more, the combination meter determines that a problem has occurred.

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 ).

STEP 2. M.U.T.-III other system diagnosis code


Check if diagnosis code is set in the KOS&OSS-ECU.

Q. Is the diagnosis code set?

Troubleshoot the KOS&OSS-ECU (Refer to GROUP 42B - Troubleshooting ).

Go to Step 3.

STEP 3. M.U.T.-III other system diagnosis code


Check if a diagnosis code, which relates to CAN communication-linked systems below, is set.

Q. Is the diagnosis code set?

Go to Step 4.

Go to Step 5.

STEP 4. Check whether the diagnosis code is set again.


Recheck if the diagnosis code is set.
(1)Erase the diagnosis code.
(2)Turn the ignition switch to "ON" position.
(3)On completion, check that the diagnosis code is not set again.

Q. Is the diagnosis code set?

Replace KOS&OSS-ECU (Refer to GROUP 42B - KOS&OSS-ECU ) and then go to Step 6.

A poor connection, open circuit or other intermittent malfunction is present in the CAN bus lines between the KOS&OSS-ECU and the combination meter (Refer to GROUP 00 - How to use troubleshooting/Inspection Service Points ).

STEP 5. Check whether the diagnosis code is set again.


Recheck if the diagnosis code is set.
(1)Erase the diagnosis code.
(2)Turn the ignition switch to "ON" position.
(3)On completion, check that the diagnosis code is not set again.

Q. Is the diagnosis code set?

Replace combination meter (Refer to ) and then go to Step 6.

A poor connection, open circuit or other intermittent malfunction is present in the CAN bus lines between the KOS&OSS-ECU and the combination meter (Refer to GROUP 00 - How to use troubleshooting/Inspection Service Points ).

STEP 6. Check whether the diagnosis code is set again.


Recheck if the diagnosis code is set.
(1)Erase the diagnosis code.
(2)Turn the ignition switch to "ON" position.
(3)On completion, check that the diagnosis code is not set again.

Q. Is the diagnosis code set?

Go to Step 1.

The procedure is complete.