Mitsubishi Grandis. Manual - part 228

SYMPTOM PROCEDURES

SMART WIRING SYSTEM (SWS) USING SWS MONITOR

54C-374

ROOM LAMP

Inspection Procedure P-1: The interior lamps (room ramp, rear personal lamps, door lamps, luggage 
compartment lamp, key illumination lamp) does not illuminate or extinguish normally.

CAUTION

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

KEY CYLINDER
ILLUMINATION
LAMP

· ROOM LAMP

· DOOR LAMP 
· LUGGAGE
  COMPARTMENT
  LAMP

· REAR PERSONAL
  LAMP

J/B SIDE

ETACS-ECU

FUSIBLE
LINK

26

Interior Lamp Circuit <without keyless entry system>

SYMPTOM PROCEDURES

SMART WIRING SYSTEM (SWS) USING SWS MONITOR

54C-375

COMMENTS ON TROUBLE SYMPTOM

The ETACS-ECU activates the interior lamps (room 
lamp, rear personal lamp, luggage compartment 
lamp, door lamps, key cylinder illumination lamp) 
according to the input signals below.

• Ignition switch (IG1)

• Door switches

• Tailgate switch

• Door key switch

• Tailgate key switch

• Driver's door lock actuator

• Interior lamp switch

• Multi-purpose fuse No.18

• Key reminder switch <vehicles with keyless entry 

system>

• Interior lamp loaded signal <vehicles with keyless 

entry system>

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

POSSIBLE CAUSES

• Malfunction of the door switches

• Malfunction of the room lamp switches

• Malfunction of the driver's door lock actuator

• Malfunction of the ETACS-ECU

• Malfunction of the key reminder switch

• Damaged harness wires and connectors

DIAGNOSTIC PROCEDURE

Step 1. Customize function by using the SWS 
monitor

Use the SWS monitor customisation function to 
confirm that "RM LMP TN OFF" is set to other than 
"0 second" (one of the settings below).

• 30 seconds

• 15 seconds

• 7.5 seconds

Q: Is the check result normal?

YES : 

Go to Step 2.

NO : 

Use the SWS monitor customisation 
function to confirm that "RM LMP TN OFF" 
is set to other than "0 second" (Refer to 

P.54C-574

).

KEY CYLINDER
ILLUMINATION
LAMP

· ROOM LAMP

· DOOR LAMP 
· LUGGAGE
  COMPARTMENT
  LAMP

· REAR PERSONAL
  LAMP

KEEP RELAY

LOAD
DETERMINATION
CIRCUIT

J/B SIDE

ETACS-ECU

FUSIBLE
LINK

26

Interior Lamp Circuit <with keyless entry system>

SYMPTOM PROCEDURES

SMART WIRING SYSTEM (SWS) USING SWS MONITOR

54C-376

Step 2. ECU check by using the SWS monitor

Check that the power supply and earth lines to the 
ETACS-ECU and the SWS communication lines are 
normal.

• Ignition switch: OFF

ECUS TO BE CHECKED

• ETACS ECU

OK: "OK" is displayed on the "ETACS ECU" 
menu.

Q: Is the check result normal?

YES : 

Go to Step 3.

NO : 

Refer to Inspection Procedure A-3 
"Communication with ETACS-ECU is not 
possible 

P.54C-63

."

Step 3. Check the illumination of the interior 
lamps.

Check that the interior lamps illuminate and 
extinguish.
NOTE: Check that the interior lamps illuminate or 
extinguish when the interior lamp switches are 
operated. For the room lamp and the rear personal 
lamps, check they illuminate when the lamp switches 
are turned to the ON or DOOR position.

Q: Which of the interior lamp does no illuminate or 

extinguish?

All of the interior lamps illuminate and extinguish 
normally. : 

The procedure is complete.

No lamps illuminate at all. : 

Replace the 

ETACS-ECU.

When the interior lamp switches are turned to the 
ON position, no lamps illuminate at all. 
Alternatively, when the interior lamp switches are 

turned to the OFF position, all the interior lamps 
illuminate. : 

Refer to inspection procedure Q-22 

"The interior lamp "all on" or "all off" switch 
signal is not sent to the ETACS-ECU 

P.54C-553

."

If the interior lamp switches are turned to the ON 
position, none of the room lamp and the rear 
personal lamps illuminate at all. : 

Go to Step 4.

The room lamp and the rear personal lamps do not 
illuminate or extinguish normally when the 
switches are at the DOOR position. : 

Go to Step 6.

Only the room lamp does not illuminate or 
extinguish normally. : 

Refer to inspection 

procedure Q-22 "The interior lamp "all on" 
or "all off" switch signal is not sent to the 
ETACS-ECU 

P.54C-553

."

Only right or left rear personal lamp does not 
illuminate or extinguish normally. : 

Refer to 

inspection procedure Q-22 "The interior 
lamp "all on" or "all off" switch signal is not 
sent to the ETACS-ECU 

P.54C-553

."

Only the luggage compartment lamp does not 
illuminate or extinguish normally. : 

Refer to 

inspection procedure Q-22 "The interior 
lamp "all on" or "all off" switch signal is not 
sent to the ETACS-ECU 

P.54C-553

."

Only the door lamps do not illuminate or 
extinguish normally. : 

Refer to inspection 

procedure Q-22 "The interior lamp "all on" 
or "all off" switch signal is not sent to the 
ETACS-ECU 

P.54C-553

."

Only the key cylinder illumination lamp does not 
illuminate or extinguish normally. : 

Refer to 

inspection procedure Q-22 "The interior 
lamp "all on" or "all off" switch signal is not 
sent to the ETACS-ECU 

P.54C-553

."

SYMPTOM PROCEDURES

SMART WIRING SYSTEM (SWS) USING SWS MONITOR

54C-377

Step 4. Connector check: C-219 ETACS-ECU 
connector and E-02 room lamp connector

Q: Is the check result normal?

YES : 

Go to Step 5.

NO : 

Repair the defective connector.

AC310626

Connector: C-219

Junction block (Rear view)

<LHD>

AB

Junction block side

AC310620

Connector: C-219

Junction block 
(Rear view)

<RHD>

AB

Junction block side

AC310651

AD

Connector: E-02 <LHD>             

Harness side

AC310655

AE

Connector: E-02 <RHD>             

Harness side