Mitsubishi Lancer Evolution IX. Manual - part 243

SYMPTOM PROCEDURES

SMART WIRING SYSTEM (SWS) USING SWS MONITOR

54C-231

FOG LAMP

INSPECTION PROCEDURE J-1: The rear fog lamp do not illuminate normally.

CAUTION

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

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

ETACS-ECU

FUSIBLE
LINK

1

COMBINATION
METER

REAR
COMBINATION
LAMP
(REAR FOG)

REAR
FOG
LAMP
RELAY

Rear Fog Lamp Circuit <LHD>

SYMPTOM PROCEDURES

SMART WIRING SYSTEM (SWS) USING SWS MONITOR

54C-232

OPERATION

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

• Tail lamp switch

• Headlamp switch

• Rear fog lamp switch

If the rear fog lamps do not illuminate normally, these 
input signal circuit(s) or the ETACS-ECU may be 
defective.

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

COMBINATION
METER

REAR
COMBINATION
LAMP
(REAR FOG)

REAR FOG
LAMP RELAY

ETACS-
ECU

FUSIBLE
LINK

1 

Rear Fog Lamp Circuit <RHD>

SYMPTOM PROCEDURES

SMART WIRING SYSTEM (SWS) USING SWS MONITOR

54C-233

POSSIBLE CAUSES

• Malfunction of the column switch

• Malfunction of the fog lamp switch

• Malfunction of the ETACS-ECU

• Damaged harness wires and connectors

DIAGNOSIS PROCEDURE

Step 1. Check that the tail lamps and headlamps 
operate.
Check that the tail lamps and headlamps illuminate 
normally.

Q: Is the check result normal?

YES : 

Go to Step 2.

NO : 

Check the tail lamps and the headlamps 
(Refer to trouble symptom chart 

P.54C-20

).

Step 2. ECU check by using the SWS monitor.
Check that the power supply and earth lines to the 
column switch (column-ECU), the ETACS-ECU and 
the front-ECU and the SWS communication lines are 
normal.

• Ignition switch: OFF

ECUS TO BE CHECKED

• COLUMN ECU

• ETACS ECU

• FRONT ECU

OK: "OK" is displayed for all the items

Q: Is the check result normal?

"OK" is displayed for all the items : 

Go to Step 3.

"NG" is displayed on the "COLUMN ECU" menu. : 

Refer to Inspection Procedure A-2 
"Communication with the column switch 
(column-ECU) is not possible 

P.54C-30

."

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

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

P.54C-36

."

"NG" is displayed on the "FRONT ECU" menu. : 

Refer to Inspection Procedure A-4 
"Communication with the front-ECU is not 
possible 

P.54C-42

."

Step 3. Function diagnosis by using the SWS 
monitor.
Check the SWS communication signal, which are 
related to the fog lamps.

<Selected item> LIGHTING - REAR FOG LAMP

• Ignition switch: ON

• Lighting switch: "TAIL" or "HEAD"

• Rear fog lamp switch: ON

OK: Normal conditions are displayed for all 
the items.

Q: Is the check result normal?

Normal conditions are displayed for all the items. : 

Go to Step 4.

Normal condition is not displayed for item 00 or 01. 
: 

Refer to Inspection Procedure L-4 "The 
column switch (lighting and turn-signal lamp 
switch) signal is not received 

P.54C-267

."

Step 4. Pulse check.
Check the input signals below, which are related to 
the rear fog lamps.

OK: The M.U.T.-II/III sounds or the voltmeter 
needle fluctuates.

Q: Is the check result normal?

All the signals are received normally. : 

Go to Step 

5.

The ignition switch (IG1) signal is not received. : 

Refer to Inspection Procedure L-2 "The 
ignition switch (IG1) signal is not received 

P.54C-261

."

The rear fog lamp switch signal is not received. : 

Refer to Inspection Procedure L-8 "The rear 
fog lamp switch signal is not received 

P.54C-277

."

Item No. Item name

Normal condition

Item 00

HEADLAMP SW

ON when the 
lighting switch is at 
HEAD

Item 01

TAIL LAMP SW

ON when the 
lighting switch is at 
TAIL

System switch

Check condition

Ignition switch (IG1)

When turned from ACC 
to ON

Rear fog lamp switch

When the rear fog lamp 
switch is turned from off 
to on

SYMPTOM PROCEDURES

SMART WIRING SYSTEM (SWS) USING SWS MONITOR

54C-234

Step 5. Connector check: C-219 rear fog lamp 
relay connector

Q: Is the check result normal?

YES : 

Go to Step 6.

NO : 

Repair the defective connector.

Step 6. Check the rear fog lamp relay.
Refer to GROUP 54A 

− Rear fog lamp 

P.54A-64

.

Q: Is the check result normal?

YES : 

Go to Step 7.

NO : 

Replace the rear fog lamp relay.

Step 7. Voltage measurement at the C-219 rear 
fog lamp relay connector

(1) Remove the rear fog lamp relay, and measure at 

the junction block side.

(2) Check the voltage between the rear fog lamp 

relay connector and body earth.

• Voltage between C-219 rear fog lamp relay 

connector terminal No.3 and body earth

• Voltage between C-219 rear fog lamp relay 

connector terminal No.4 and body earth

OK: System voltage

Q: Is the check result normal?

YES : 

Go to Step 9.

NO : 

Go to Step 8.

AC310448

Junction block (front view)

Connector: C-219

AN

<LHD>

Junction block side

3

1

2
4

AC310458

Junction block (front view)

Connector: C-219

AK

<RHD>

Junction block side

3

1

2
4

AC310448

Junction block (front view)

Connector: C-219

AN

<LHD>

Junction block side

3

1

2
4

AC310458

Junction block (front view)

Connector: C-219

AK

<RHD>

Junction block side

3

1

2
4

AC301541HC

Connector C-219
(Junction block side)

4

2 1

3