Mitsubishi Lancer (4A9 engine). Manual — part 135

INTERIOR LAMP

CHASSIS ELECTRICAL

54A-202

SYMPTOM PROCEDURES

Inspection Procedure 1: The front room lamp does not illuminate normally.

CAUTION

Whenever the ECU is replaced, ensure that the power supply circuit, the earth circuit and the commu-
nication circuit are normal.

Front Room Lamp Circuit

ETACS-ECU

FRONT
ROOM
LAMP

Wire colour code
B : Black LG : Light green G : Green L : Blue W : White Y : Yellow SB : Sky blue
BR : Brown O : Orange GR : Grey R : Red P : Pink V : Violet PU : Purple SI : Silver

AC612709

AJ

Connector: C-316 <LHD>

ETACS-ECU

AC612717

AJ

Connector: C-316 <RHD>
ETACS-ECU

INTERIOR LAMP

CHASSIS ELECTRICAL

54A-203

OPERATION
The ETACS-ECU illuminates and extinguishes the
front room lamp in accordance with the input signals
below.

• Ignition switch (IG1)

• Key reminder switch

• Door switches

• Front door lock actuator (driver’s side)

COMMENTS ON TROUBLE SYMPTOM
If this does not work normally, the above switch input
circuit(s), front room lamp, 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

(driver’s side)

• Malfunction of front room lamp

• Malfunction of the ETACS-ECU

• Damaged harness wires and connectors

DIAGNOSIS PROCEDURE

STEP 1. Rear room lamp operation check
Check that the rear room lamp illuminates and extin-
guishes normally.

Q: Is the check result normal?

YES :

Go to Step 4.

NO :

Go to Step 2.

STEP 2. M.U.T.-III diagnosis code
Check if diagnosis code is set to the ETACS-ECU.

Q: Is the diagnosis code set?

YES :

Troubleshoot the ETACS-ECU. Refer to .

NO :

Go to Step 3.

STEP 3. M.U.T.-III data list
Use the ETACS-ECU service data to check the sig-
nals related to the operation of front room lamp.

• Turn the ignition switch to the LOCK (OFF) posi-

tion.

• Remove the ignition key from the ignition key cyl-

inder.

• Open each door.

OK: Normal conditions are displayed for all
the items.

Q: Is the check result normal?

AC612722

AF

Connector: D-03

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 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

INTERIOR LAMP

CHASSIS ELECTRICAL

54A-204

Normal conditions are displayed for all the items. :

Replace the ETACS-ECU.

Normal condition is not displayed for item No. 228.
:

Troubleshoot the ETACS-ECU. Refer to
Inspection Procedure 4 "The front door lock
actuator (driver’s side) signal is not
received" <L.H. drive vehicles> or <R.H.
drive vehicles>.

Normal condition is not displayed for item No. 254.
:

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

Normal condition is not displayed for item No. 256.
:

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

Normal condition is not displayed for item No. 257.
:

Troubleshoot the ETACS-ECU. Refer to
Inspection Procedure 6 "The front door
switch (passenger’s side) signal is not
received" .

Normal condition is not displayed for item No. 258.
:

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

Normal condition is not displayed for item No. 259.
:

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

Normal condition is not displayed for item No. 264.
:

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

STEP 4. Connector check: D-03 front room lamp
connector

Q: Is the check result normal?

YES :

Go to Step 5.

NO :

Repair the defective connector.

STEP 5. Front room lamp bulb check
Check that the front room lamp bulb is normal.

Q: Is the check result normal?

YES :

Go to Step 6.

NO :

Replace the front room lamp bulb.

STEP 6. Connector check: C-316 ETACS-ECU
connector

Q: Is the check result normal?

YES :

Go to Step 7.

NO :

Repair the defective connector.

STEP 7. Wiring harness check between the D-03
front room lamp connector terminal No. 2/3 and
the C-316 ETACS-ECU connector terminal No. 6/5

• Check the input/output line for open circuit.

Q: Is the check result normal?

YES :

Go to Step 8.

NO :

Repair the wiring harness.

STEP 8. Connector check: D-03 front room lamp
connector

Q: Is the check result normal?

YES :

Go to Step 9.

NO :

Repair the defective connector.

STEP 9. Wiring harness check between the D-03
front room lamp connector terminal No. 1 and the
body earth

• Check the output lines for open circuit.

Q: Is the check result normal?

YES :

Replace the front room lamp, and then go to

Step 10.

NO :

Repair the wiring harness.

STEP 10. Retest the system
Check that the front room lamp illuminates/extin-
guishes normally.

Q: Is the check result 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 ).

NO :

Replace the front room lamp.

INTERIOR LAMP

CHASSIS ELECTRICAL

54A-205

Inspection Procedure 2: The rear room lamp does not illuminate normally.

CAUTION

Whenever the ECU is replaced, ensure that the power supply circuit, the earth circuit and the commu-
nication circuit are normal.

OPERATION
The ETACS-ECU illuminates and extinguishes the
rear room lamp in accordance with the input signals
below.

• Ignition switch (IG1)

• Key reminder switch

• Door switches

• Front door lock actuator (driver’s side)

COMMENTS ON TROUBLE SYMPTOM
If this does not work normally, the above switch input
circuit(s), rear room lamp, or ETACS-ECU may have
a problem.

Rear Room Lamp Circuit

ETACS-ECU

REAR
ROOM
LAMP

Wire colour code
B : Black LG : Light green G : Green L : Blue W : White Y : Yellow SB : Sky blue
BR : Brown O : Orange GR : Grey R : Red P : Pink V : Violet PU : Purple SI : Silver

AC612709

AJ

Connector: C-316 <LHD>

ETACS-ECU

AC612717

AJ

Connector: C-316 <RHD>
ETACS-ECU

AC801769AH

Connector: D-07

D-07 (GR)