Inspection Procedure 3: Malfunction of the ignition switch power supply system


caution Whenever the ECU is replaced, ensure that the input and output signal circuits are normal.






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



DIAGNOSIS PROCEDURE

STEP 1. Connector check: B-240 ignition switch connector

Q. Is the check result normal?
Go to Step 2.
Repair the defective connector.

STEP 2. Voltage measurement at ignition switch connector B-240 in order to check the battery circuit of power supply system to the ignition switch.
(1)Disconnect the ignition switch connector B-240 and measure at the wiring harness side.
(2)Measure the voltage between terminal 1 and earth.
OK: System voltage

Q. Is the check result normal?
Go to Step 4.
Go to Step 3.

STEP 3. Check the wiring harness from ignition switch connector B-240 (terminal No.1) to fusible link (1).

  • Check the battery power supply line for open and short circuit.

Q. Is the check result normal?
Go to Step 5.
Repair the 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 ).
Return to Step 1.