Code No.U1004 AS&G CAN timeout



caution
  • If diagnosis code No. U1004 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 AS&G-ECU cannot be received, the ETACS-ECU sets the diagnosis code No. U1004.

JUDGEMENT CRITERIA


After the following statuses continue to be true for 5 seconds, if the communication with the AS&G-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 M.U.T.-III to diagnose the CAN bus lines.

Q. Is the check result normal?

Go to Step 2.

Repair the CAN bus lines. (Refer to GROUP 54C - Troubleshooting .)

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


Check if a diagnosis code is set to the AS&G-ECU.

Q. Is the diagnosis code set?

Perform troubleshooting for the AS&G-ECU. (Refer to GROUP 17 - Troubleshooting .)

Go to Step 3.

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


Check if the diagnosis code No. U1004 is set to the 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 ETACS-ECU.
(1)Erase the diagnosis code.
(2)Turn the ignition switch from the LOCK (OFF) position to the ON position.
(3)Check if the diagnosis code is set.

Q. Is the diagnosis code set?

Replace the AS&G-ECU. Go to Step 5.

A poor connection, open circuit, or other intermittent malfunction in the CAN bus line between the AS&G-ECU and ETACS-ECU. (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.


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

Q. Is the diagnosis code set?

Replace the ETACS-ECU.

A poor connection, open circuit, or other intermittent malfunction in the CAN bus line between the AS&G-ECU and ETACS-ECU. (Refer to GROUP 00 - How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunction .)