Code No.U0100 Engine CAN timeout



caution
  • If diagnosis code No. U0100 is set to 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 sets the 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 set to the engine-ECU.

Q. Is the diagnosis code set?

Troubleshoot the engine (Refer to GROUP 13A - Diagnosis Code Chart <4B1>, GROUP 13C -Troubleshooting <4J1>, GROUP 13D -Troubleshooting <4N1>).

Go to Step 3

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


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

Q. Is the diagnosis code set?

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 reset.


Check again if the diagnosis code is set to 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 set.

Q. Is the diagnosis code set?

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 ).