Inspection Procedure
2: Malfunction of the ignition switch power supply system
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 Immobilizer System - How
to Register Key ID .)
COMMENTS ON TROUBLE SYMPTOM
When the power supply system of ignition switch has a problem, none of the equipment and
system connected to the ignition switch works even if the ignition switch is operated.
POSSIBLE CAUSES
Malfunction of the ignition switch
Malfunction of the fuse
Malfunction of the ETACS-ECU
Damaged harness wires and connectors
DIAGNOSIS PROCEDURE
STEP 1. Voltage measurement at ignition switch connector
(1)Disconnect the ignition switch connector and measure the voltage at ignition switch
connector harness side.
(2)Check the voltage between the ignition switch connector (power supply terminal)
and body earth. OK: System voltage
Q.
Is the check result normal?
Go to Step 4.
Go to Step 2.
STEP 2. Check the fuse.
Q.
Is the check result normal?
Go to Step 3.
Replace the fuse. (Check that there is not a short to earth in the circuit of
lower reaches before replacing. If there are any problems, replace the fuse after the circuit
of lower reaches is repaired.)
STEP 3. Check of open circuit in IG+ line between ignition
switch connector and ETACS-ECU connector.
Q.
Is the check result normal?
Go to Step 4.
Repair the connector(s) or wiring harness.
STEP 4. Check the ignition switch.
Refer to .
Q.
Is the ignition switch in good condition?
Go to Step 5.
Replace the ignition switch.
STEP 5. Retest the system.
Q.
Do the device and the system work normally when the ignition switch is operated?
The trouble can be an intermittent malfunction (Refer to GROUP 00 - How
to Cope with Intermittent Malfunction ).