Code No.U1519 No bus activity for LIN(Theft) <Vehicles with security alarm sensor>


caution
  • 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 GROUP 54A, Immobilizer System - How to Register Key ID .)

TROUBLE JUDGMENT


The ETACS-ECU will store diagnosis code No. U1519 when no communication has been carried out for more than a certain period after it received last valid data.

PROBABLE CAUSES



DIAGNOSIS PROCEDURE

STEP 1. Measure the voltage at the LIN bus lines.
Check the LIN bus line for short to power supply.
(1)Disconnect all the connector which are connecter to the LIN bus lines.
(2)Turn the ignition switch from "LOCK" (OFF) to "ON" position.
(3)Measure the voltage between the security alarm siren connector (power supply terminal) and the body earth.

  • The voltmeter needle does not swing.
note If the LIN bus line are short to power supply, the voltmeter indicates a constant value.

Q. Is the check result normal?
Go to Step 2.
Repair the connector(s) or wiring harness.

STEP 2. Measure the resistance at the LIN bus lines.
Check the LIN bus line for short to earth.
(1)Disconnect all the connector which are connecter to the LIN bus lines.
(2)Measure the resistance between the security alarm siren connector (earth terminal) and the body earth.

  • No continuity (1 kΩ or more)

Q. Is the check result normal?
Go to Step 3.
Repair the connector(s) or wiring harness.

STEP 3. Check the security alarm siren.
Disconnect security alarm siren connector, and recheck whether diagnosis code No. U1515 is set.
(1)Connect all the relevant ECUs, and disconnect lighting control sensor connector only.
(2)Erase the diagnosis code.
(3)Turn the ignition switch from "LOCK" (OFF) to "ON" position.
(4)Check whether diagnosis code No. U1515 is set.
note If diagnosis code No. U1515 is not set, diagnosis code No. U1006 is set because the security alarm siren is disconnected. This is normal.
(5)Turn the ignition switch to the "LOCK" (OFF) position.

Q. Is diagnosis code No. U1515 set?
Reconnect the security alarm siren connector, and go to Step 4.
Replace the security alarm siren.

STEP 4. Recheck for diagnosis code.
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) to "ON" position.
(3)Check whether diagnosis code No. U1515 is set.
(4)Turn the ignition switch to the "LOCK" (OFF) position.

Q. Is the diagnosis code set?
Replace the ETACS-ECU.
The trouble can be an intermittent malfunction (Refer to GROUP 00 - How to Cope with Intermittent Malfunction ).