Code No.U1000 OSS CAN timeout



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

DIAGNOSIS FUNCTION


When the signal from OSS-ECU cannot be received, KOS-ECU sets the diagnosis code No.U1000.

PROBABLE CAUSES




DIAGNOSIS PROCEDURE


STEP 1. M.U.T.-III CAN bus diagnostics


Use 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 2.

STEP 2. Check the M.U.T.-III Diagnosis code for other systems


Check that the OSS-ECU set a diagnosis code.

Q. Is the diagnosis code set?

Diagnose the OSS-ECU. Refer to Troubleshooting .

Go to Step 3

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


Check if diagnosis code No.U1000 is set to the 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.


Recheck if the diagnosis code is set.
(1)Erase the diagnosis code.
(2)Turn the power supply mode of the engine switch from OFF to ON.
(3)Check if the diagnosis code is set.

Q. Is the diagnosis code set?

Replace the OSS-ECU.

Intermittent malfunction is suspected (Refer to GROUP 00 - How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunction ).

STEP 5. Check whether the diagnosis code is reset.


Recheck if the diagnosis code is set.
(1)Erase the diagnosis code.
(2)Turn the power supply mode of the engine switch from OFF to ON.
(3)Check if the diagnosis code is set.

Q. Is the diagnosis code set?

Replace KOS-ECU and register the ID codes (Refer to ).

Intermittent malfunction is suspected (Refer to GROUP 00 - How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunction ).