Inspection Procedure 1: When the power supply mode of electric motor switch is turned on, the AVAS-OFF indicator does not illuminate. (Does not illuminate as initial check)



caution Before replacing the ECU, ensure that the power supply circuit, the earth circuit and the communication circuit are normal.


PROBABLE CAUSES




DIAGNOSIS PROCEDURE


STEP 1. M.U.T.-III other system diagnosis code


Check if diagnosis code is stored in the combination meter.

Q. Is the diagnosis code stored?

Troubleshoot the combination meter. Refer to .

Go to Step 2.

STEP 2. Check the AVAS-OFF indicator.


Check whether the AVAS-OFF indicator on the combination meter works normally.

Q. Is the check result normal?

Go to Step 5.

Go to Step 3.

STEP 3. Check of short to power supply and open circuit in IND line between acoustic vehicle alerting-ECU connector and combination meter connector.


Q. Is the check result normal?

Go to Step 4.

Repair the connector(s) or wiring harness.

STEP 4. Check by M.U.T.-III "Special Function"


Using M.U.T.-III, select "Test" from the special function of the combination meter.

Q. Is the check result normal?

Go to Step 5.

Replace the combination meter.

STEP 5. Resistance measurement at acoustic vehicle alerting-ECU connector (GND terminal)


(1)Disconnect the connector, and measure at the wiring harness side.
(2)Measure the resistance between the acoustic vehicle alerting-ECU connector (GND terminal) and body earth.
OK: Continuity exists (2 Ω or less)

Q. Is the check result normal?

Go to Step 7.

Go to Step 6.

STEP 6. Check of short to earth and open circuit in GND line between acoustic vehicle alerting-ECU connector and body earth.


Q. Is the check result normal?

The trouble can be an intermittent malfunction (Refer to GROUP 00 - How to use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunction ).

Repair the connector(s) or wiring harness.

STEP 7. Voltage measurement at acoustic vehicle alerting-ECU connector IG1 terminal.


(1)Disconnect the connector, and measure at the wiring harness side.
(2)Turn the power supply mode of the electric motor switch to ON.
(3)Check the voltage between the acoustic vehicle alerting-ECU connector IG1 terminal and body earth.
OK: System voltage

Q. Is the check result normal?

Go to Step 9.

Go to Step 8.

STEP 8. Check of short to power supply and open circuit in IG1 IND line between acoustic vehicle alerting-ECU connector and electric motor switch (ON).


Q. Is the check result normal?

The trouble can be an intermittent malfunction (Refer to GROUP 00 - How to use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunction ).

Repair the connector(s) or wiring harness.

STEP 9. Retest the system.


Check that the AVAS works normally.

Q. Is the check result normal?

The trouble can be an intermittent malfunction (Refer to GROUP 00 - How to use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunction ).

Replace the acoustic vehicle alerting-ECU.