54A-IGNITION KEY CYLINDER ILLUMINATION LIGHT DOES NOT ILLUMINATE/EXTINGUISH NORMALLY.

Inspection Procedure 1: The ignition key cylinder illumination light does not illuminate/extinguish normally.

caution

Before replacing the ECU, ensure that the power supply circuit, the ground 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 .)

OPERATION

The ETACS-ECU operates this function in accordance with the input signals below.

Ignition switch (IG1)
Key reminder switch
Driver's door switch
Driver's door lock actuator

TECHNICAL DESCRIPTION (COMMENT)

If this function does not work normally, these input signal circuit(s), the ignition key cylinder illumination light or the ETACS-ECU may be defective.

TROUBLESHOOTING HINTS

The key reminder switch may be defective
The driver's door switch may be defective
The driver's door lock actuator may be defective
The ignition key cylinder illumination light bulb may be defective
The ETACS-ECU may be defective
The wiring harness or connectors may have loose, corroded, or damaged terminals, or terminals pushed back in the connector

DIAGNOSIS

Required Special Tools:

MB992006: Extra fine probe
MB991223: Harness set

STEP 1. Using scan tool (M.U.T.-III), read the diagnostic trouble code.

(1)

caution

To prevent damage to scan tool (M.U.T.-III), always turn the ignition switch to the "LOCK" (OFF) position before connecting or disconnecting scan tool (M.U.T.-III).

Connect scan tool (M.U.T.-III). Refer to "How to connect Scan tool (M.U.T.-III)

(2) Turn the ignition switch to the "ON" position.

(3) Check whether the ETACS-ECU related DTC is set.

(4) Turn the ignition switch to the "LOCK" (OFF) position.

Is the DTC set?

Troubleshoot the ETACS-ECU. Refer to

Go to Step 2

STEP 2. Using scan tool (M.U.T.-III), check data list.

Check the signal related to the operation of ignition key cylinder illumination light.

Turn the ignition switch to the LOCK "(OFF)" position.
Remove the ignition key from the ignition key cylinder.
Open the driver's door.

Item No.	Item name	Normal condition
Item 228	Dr door unlock	ON
Item 254	IG voltage	1 V or less
Item 256	Dr door ajar switch	Open
Item 264	Handle lock switch	Key in → Key out

Item No.	Item name	Normal condition
Item 228	Dr door unlock	ON
Item 254	IG voltage	1 V or less
Item 256	Dr door ajar switch	Open
Item 264	Handle lock switch	Key in → Key out

OK: Normal conditions are displayed for all the items.

Is the check result normal?

: Go to Step 3

: Troubleshoot the ETACS-ECU. Refer to Inspection Procedure 4 "The front door lock actuator (driver’s side) signal is not received

: Troubleshoot the ETACS-ECU. Refer to Inspection Procedure 2 "The ignition switch (IG1) signal is not received

: Troubleshoot the ETACS-ECU. Refer to Inspection Procedure 5 "The front door switch (driver’s side) signal is not received

: Troubleshoot the ETACS-ECU. Refer to Inspection Procedure 3 "The key reminder switch signal is not received

STEP 3. Check of ignition key cylinder illumination light bulb

Check that the ignition key cylinder illumination light bulb is normal.

Is the check result normal?

Go to Step 4

Replace the bulb of the ignition key cylinder illumination light.

STEP 4. Check of open circuit in (LP+3, RLP-) line between key reminder switch connector and ETACS-ECU connector.

Is the check result normal?

Go to Step 5

Repair the connector(s) or wiring harness.

STEP 5. Retest the system

Check that the ignition key cylinder illumination light illuminates/extinguishes normally.

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 ETACS-ECU.