54A-FRONT DOME LIGHT DOES NOT ILLUMINATE NORMALLY.

Inspection Procedure 1: The front dome light does not illuminate normally.

caution

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

OPERATION

The ETACS-ECU illuminates and extinguishes the front dome light in accordance with the input signals below.

Ignition switch (IG1)
Key reminder switch
Door switches
Front door lock actuator (driver’s side)

TECHNICAL DESCRIPTION (COMMENT)

If this does not work normally, the above switch input circuit(s), front dome light, or ETACS-ECU may have a problem.

TROUBLESHOOTING HINTS

The key reminder switch may be defective
The door switch may be defective
The front door lock actuator (driver’s side) may be defective
The front dome light 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. Rear dome light operation check.

Check that the rear dome light illuminates and extinguishes normally.

Is the check result normal?

Go to Step 4

Go to Step 2

STEP 2. Using scan tool (M.U.T.-IIISE), read the DTC.

(1)

caution

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

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

(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 3

STEP 3. Using scan tool (M.U.T.-IIISE), check data list.

Use the ETACS-ECU data list to check the signals related to the operation of front dome light.

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

Item No.	Item name	Normal condition
59	Driver’s door unlock	ON
79	IG voltage	1 V or less
81	Driver’s door ajar switch	Open
82	Passenger’s door ajar switch	Open
83	Rear right door ajar switch	Open
84	Rear left door ajar switch	Open
88	Steering wheel lock switch	Key in → Key out

OK: Normal conditions are displayed for all the items.

Is the check result normal?

: Replace the ETACS-ECU.

: 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 6 "The front door switch (passenger’s side) signal is not received"

: Troubleshoot the ETACS-ECU. Refer to Inspection Procedure 7 "The rear door switch (RH) signal is not received"

: Troubleshoot the ETACS-ECU. Refer to Inspection Procedure 8 "The rear door switch (LH) signal is not received"

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

STEP 4. Front dome light bulb check.

Check that the front dome light bulb is normal.

Is the check result normal?

Go to Step 5

Replace the front dome light bulb.

STEP 5. Check of open or short to ground circuit in LP+1 line between the front dome light connector and ETACS-ECU connector.

Is the check result normal?

Go to Step 6

Repair the connector(s) or wiring harness.

STEP 6. Check of open or short to ground circuit in RLP- line between the front dome light connector and ETACS-ECU connector.

Is the check result normal?

Go to Step 7

Repair the connector(s) or wiring harness.

STEP 7. Check of open circuit in ground line between the front dome light connector and body ground.

Is the check result normal?

Replace the front dome light, and then go to Step 8

Repair the connector(s) or wiring harness.

STEP 8. Retest the system.

Check that the front dome 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.