Code No.U0100 Engine CAN timeout



caution
  • If diagnosis code No. U0100 is stored in the ETACS-ECU, always diagnose the CAN bus line.
  • Before replacing the ECU, ensure that the power supply circuit, the earth circuit and the communication circuit are normal.
  • When the ETACS-ECU of vehicles without KOS is replaced, the encrypted code of the ignition key needs to be registered to the ETACS-ECU. (If the encrypted code is not registered, the engine cannot be started. Register the encrypted code as described in Immobilizer System - How to Register Key ID .)

DIAGNOSTIC FUNCTION


If the signal from engine-ECU cannot be received, the ETACS-ECU stores diagnosis code No. U0100.

JUDGEMENT CRITERIA


After the following statuses continue to be true for 5 seconds, if the communication with the engine-ECU cannot be established for 600 ms or more, the ETACS-ECU 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 stored in the engine-ECU.

Q. Is the diagnosis code stored?

Troubleshoot the engine (Refer to GROUP 13A - Diagnosis Code Chart <2000, 2400>, GROUP 13B - Troubleshooting <3000>).

Go to Step 3.

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


Check if diagnosis code No. U0100 is stored in the CVT-ECU or A/T-ECU, 4WD-ECU, ABS-ECU and ASC-ECU.

Q. Is the diagnosis code stored?

Go to Step 4.

Go to Step 5.

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


Check again if the diagnosis code is stored in the ETACS-ECU.
(1)Erase the diagnosis code.
(2)Turn the ignition switch from "LOCK" (OFF) position to "ON" position.
(3)Check if diagnosis code is stored.

Q. Is the diagnosis code stored?

Replace the engine-ECU.

The trouble can be an intermittent malfunction such as a poor connection or open circuit in the CAN bus lines between the engine-ECU and the ETACS-ECU (GROUP 00 - How to use Troubleshooting/inspection Service Points - How to Cope with Intermittent Malfunction ).

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


Check again if the diagnosis code is stored in the ETACS-ECU.
(1)Erase the diagnosis code.
(2)Turn the ignition switch from "LOCK" (OFF) position to "ON" position.
(3)Check if diagnosis code is stored.

Q. Is the diagnosis code stored?

Replace the ETACS-ECU.

The trouble can be an intermittent malfunction such as a poor connection or open circuit in the CAN bus lines between the engine-ECU and the ETACS-ECU (GROUP 00 - How to use Troubleshooting/inspection Service Points - How to Cope with Intermittent Malfunction ).