Mitsubishi Evolution X. Manual - part 971

DOME LIGHT

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CHASSIS ELECTRICAL

54A-245

STEP 2. Using scan tool MB991958, read the diagnostic 
trouble code. 

CAUTION

To prevent damage to scan tool MB991958, always turn the 
ignition switch to the "LOCK" (OFF) position before con-
necting or disconnecting scan tool MB991958.
(1) Connect scan tool MB991958. Refer to "How to connect 

scan tool (M.U.T.-III) 

P.54A-241

."

(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.
Q: Is the DTC set?

YES : Diagnose the ETACS-ECU. Refer to ETACS, 

Diagnosis 

P.54A-582

.

NO :  Go to Step 3.

AC608435

Data link connector

MB991827

MB991824

MB991910

AB

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STEP 3. Using scan tool MB991958, check data list.
Use the ETACS-ECU data list to check the signals related to 
the front dome light.

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

• Remove the ignition key from the ignition key cylinder.

• Open each door.

Q: Does scan tool MB991958 display the items "Dr door 

unlock", "IG voltage", "Dr door ajar switch", "As door 
ajar switch", "RR door ajar switch", "RL door ajar 
switch" and "Handle lock switch" as normal condition?
YES  : (Normal conditions are displayed for all items.) Go to 

Step 4.

NO  :  (Normal condition is not displayed.) Troubleshoot the 

ETACS-ECU. Refer to ETACS, Diagnosis, Input 
signal chart 

P.54A-639

.

STEP 4. Check front dome light connector D-03 for loose, 
corroded or damaged terminals, or terminals pushed back 
in the connector.
Q: Is front dome light connector D-03 in good condition?

YES : Go to Step 5.
NO :  Repair or replace the damaged component(s). Refer 

to GROUP 00E, Harness Connector Inspection 

P.00E-2

.

STEP 5. Front dome light bulb check
Check that the front dome light bulb is normal.
Q: Is front dome light bulb normal?

YES : Go to Step 6.
NO :  Replace the front dome light bulb.

STEP 6. Check ETACS-ECU connector C-316 for loose, 
corroded or damaged terminals, or terminals pushed back 
in the connector.
Q: Is ETACS-ECU connectors C-316 in good condition?

YES : Go to Step 7.
NO :  Repair or replace the damaged component(s). Refer 

to GROUP 00E, Harness Connector Inspection 

P.00E-2

.

Item No.

Item name

Normal condition

Item 228

Dr door unlock

ON

Item 254

IG voltage

0 V

Item 256

Dr door ajar switch

Open

Item 257

As door ajar switch

Open

Item 258

RR door ajar switch

Open

Item 259

RL door ajar switch

Open

Item 264

Handle lock switch

Key in 

→ Key out

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STEP 7. Check the wiring harness between front dome 
light connector D-03 (terminal 2, 3) and ETACS-ECU 
connector C-316 (terminal 6, 5)
Q: Are wiring harness between front dome light connector 

D-03 (terminal 2, 3) and ETACS-ECU connector C-316 
(terminal 6, 5) in good condition?
YES : Go to Step 8.
NO :  The wiring harness may be damaged or the 

connector(s) may have loose, corroded or damaged 
terminals, or terminals pushed back in the connector. 
Repair the wiring harness as necessary.

STEP 8. Check the wiring harness between front dome 
light connector D-03 (terminal 1) and body ground.
Q: Is wiring harness between front dome light connector 

D-03 (terminal 1) and body ground in good condition?
YES : Replace the front dome light, and then go to Step 9.
NO :  The wiring harness may be damaged or the 

connector(s) may have loose, corroded or damaged 
terminals, or terminals pushed back in the connector. 
Repair the wiring harness as necessary.

STEP 9. Retest the system
Check that the front dome light illuminates and extinguishes 
normally.
Q: Do the front dome light work normal?

YES : The trouble can be an intermittent malfunction (Refer 

to GROUP 00, How to use 
Troubleshooting/inspection Service Points, How to 
Cope with Intermittent Malfunction 

P.00-15

).

NO :  Replace the ETACS-ECU.

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Inspection Procedure 2: The rear dome light does not illuminate normally.

CAUTION

Whenever the ECU is replaced, ensure that the power supply circuit, the ground circuit and the com-
munication circuit are normal.

.

TROUBLE JUDGMENT

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

• Ignition switch (IG1)

• Key reminder switch

• Door switches

• Front door lock actuator

.

TECHNICAL DESCRIPTION (COMMENT)

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

.

PROBABLE CAUSES

• Malfunction of the key reminder switch

• Malfunction of door switch

• Malfunction of the front door lock actuator (RH)

• Malfunction of rear dome light

• Malfunction of the ETACS-ECU

• The wiring harness or connectors may have 

loose, corroded, or damaged terminals, or termi-
nals pushed back in the connector

Rear Dome Light Circuit

ETACS-ECU

REAR
DOME
LIGHT

AC708972AI

Connector: C-316

Junction block

AC708955

Connector: D-07

AX

D-07 (GR)