Mitsubishi Grandis. Manual — part 204

SYMPTOM PROCEDURES

SMART WIRING SYSTEM (SWS) USING SWS MONITOR

54C-278

Inspection Procedure M-3: The high-beam headlamps do not illuminate normally.

CAUTION

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

COMMENTS ON TROUBLE SYMPTOM

If the high-beam headlamps do not illuminate, the
dimmer switch input circuit or the front-ECU may be
defective.

POSSIBLE CAUSES

• Malfunction of the column switch

• Malfunction of the front-ECU

• Damaged harness wires and connectors

DIAGNOSIS PROCEDURE

Step 1. ECU check by using the SWS monitor.

Check that the power supply and earth lines to the
column switch (column-ECU) and the front-ECU and
the SWS communication lines are normal.

• Ignition switch: OFF

ECUS TO BE CHECKED

• COLUMN ECU

• FRONT ECU

OK: "OK" are displayed for all the items

Q: Are the check result normal?

"OK" are displayed for all the items :

Go to Step 2.

"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-56

."

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

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

P.54C-70

."

FUSIBLE LINK

26

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

FRONT-ECU

HEADLAMP
RELAY: HI

RELAY
BOX

INPUT SIGNAL

· HEADLAMP AUTOMATIC
SHUTDOWN
· HEADLAMP SWITCH

HEADLAMP (HI: LH)

HEADLAMP (HI: RH)

Headlamp Relay (High-Beam) Circuit

SYMPTOM PROCEDURES

SMART WIRING SYSTEM (SWS) USING SWS MONITOR

54C-279

Step 2. Function diagnosis by using the SWS
monitor.

Check the SWS communication signal, which are
related to the high-beam headlamps.

<Selected item> LIGHTING - HEADLAMP HI

• Ignition switch: ON

• Lighting switch: HEAD

• Dimmer switch: from OFF to ON, and then to

OFF again

OK: Normal conditions are displayed for all
the items

Q: Are the check result normal?

Normal conditions are displayed for all the items. :

Go to Step 3.

Normal condition is not displayed for item Nos.00,
02 or 03. :

Refer to inspection procedure Q-6 "The

column switch (lighting and turn-signal lamp
and headlamp washer switch) signal is not
received

P.54C-478

."

Normal condition is not displayed for item No.30. :

Refer to inspection procedure Q-2 "The
ignition switch (IG1) signal is not received

P.54C-460

."

Normal condition is not displayed for item No.35. :

Refer to Inspection Procedure M-5 "The
headlamp automatic-shutdown function
does not work normally

P.54C-280

."

Normal condition is not displayed for item No.70. :

Replace the front-ECU.

Step 3. Retest the system.

Check that the high-beam headlamps illuminate
normally.

Q: Is the check result normal?

YES :

The trouble can be an intermittent

malfunction (Refer to GROUP 00

− How to

Cope with Intermittent Malfunction

P.00-5

).

NO :

Replace the front-ECU.

Inspection Procedure M-4: The high-beam and low-beam headlamps do not illuminate when the
passing switch is operated.

CAUTION

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

COMMENTS ON TROUBLE SYMPTOM

If the low-beam and high-beam headlamps are
normal, the passing switch input signal circuit or the
front-ECU may be defective.

POSSIBLE CAUSES

• Malfunction of the column switch

• Malfunction of the front-ECU

• Damaged harness wires and connectors

DIAGNOSIS PROCEDURE

Step 1. Check the operation of the headlamps.

Check that the low-beam and high-beam headlamps
illuminate normally.

Q: Is the check result normal?

YES :

Go to Step 2.

NO :

Repair the headlamps. Refer to trouble
symptom chart

P.54C-44

.

Item No. Item name

Normal condition

Item 00

HEADLAMP
SW

ON

Item 02

DIMMER SW

from OFF to ON, and
then to OFF again ("ON"
should be displayed
when the dimmer switch
is operated)

Item 03

PASSING SW OFF

Item 30

IG SW(IG1)

ON

Item 35

HD
AUTO-CUT

OFF

Item 70

FRONT ECU
ACK

NORMAL ACK

SYMPTOM PROCEDURES

SMART WIRING SYSTEM (SWS) USING SWS MONITOR

54C-280

Step 2. SWS monitor data list.

Check the ETACS-ECU signals which are related to
the headlamps.

<Selected item> COLUMN ECU

• Passing lamp switch: ON

OK: Normal condition is displayed.

Q: Is the check result normal?

YES :

Go to Step 3.

NO :

Refer to inspection procedure Q-6 "The
column switch (lighting and turn-signal lamp
and headlamp washer switch) signal is not
received

P.54C-478

."

Step 3. Retest the system.

When the passing switch is turned on, check if the
headlamps illuminate normally.

Q: Is the check result normal?

YES :

The trouble can be an intermittent

malfunction (Refer to GROUP 00

− How to

Cope with Intermittent Malfunction

P.00-5

).

NO :

Replace the front-ECU.

Inspection Procedure M-5: The headlamp automatic-shutdown function does not work normally.

CAUTION

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

COMMENTS ON TROUBLE SYMPTOM

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

• Ignition switch (IG1)

• Driver's door switch

• Tail lamp switch

• Headlamp switch

If this function does not work normally, these input
signal circuit(s), the front-ECU or the ETACS-ECU
may be defective. On vehicles with keyless entry
system, note that this function can be
disabled/enabled by the customize function (default
setting; enabled).

POSSIBLE CAUSES

• Malfunction of the driver's door switch

• Malfunction of the front-ECU

• Malfunction of the column switch

• Malfunction of the ETACS-ECU

• Damaged harness wires and connectors

Item No.

Item name

Normal
condition

Item 03

PASSING SW

ON

ETACS-ECU

INPUT SIGNAL

· DRIVER'S DOOR SWITCH

· TAIL LAMP SWITCH

· IGNITION SWITCH (IG1)

· HEADLAMP SWITCH

Headlamp Automatic Shutdown Function

SYMPTOM PROCEDURES

SMART WIRING SYSTEM (SWS) USING SWS MONITOR

54C-281

DIAGNOSIS PROCEDURE

Step 1. Check the SWS monitor Customize
function function.

Check that "H/L AUTO CUT" is set to "W.FUNCTION
(A)" or "W.FUNCTION (D)" by using the adjustment
function.

Q: Is the check result normal?

YES :

Go to Step 2.

NO :

Set "H/L AUTO CUT" to "W.FUNCTION (A)"
or "W.FUNCTION (D)" by using the
adjustment function. (Refer to

P.54C-574

).

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" are displayed for all the items

Q: Are the check result normal?

"OK" are 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-56

."

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

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

P.54C-63

."

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

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

P.54C-70

."

Step 3. SWS monitor data list.

Check the SWS communication signal, which are
related to the headlamp automatic-shutdown
function.

<Selected item> LIGHTING - HD AUTO-CUT

• Ignition switch: from ON to OFF

• Lighting switch: "TAIL" or "HEAD"

Check that the MUT-III displays normal condition
when the condition above is changed to the condition
below.

• Driver's door: open

OK: Normal conditions are displayed for all
the items

Q: Are the check result normal?

Normal conditions are displayed for all the items :

Go to Step 4.

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

Refer to inspection procedure Q-6 "The

column switch (lighting and turn-signal lamp
switch) signal is not received

P.54C-478

."

Normal condition is not displayed for item No.30. :

Refer to inspection procedure Q-2 "The
ignition switch (IG1) signal is not received

P.54C-460

."

Normal condition is not displayed for item No.32. :

Refer to inspection procedure Q-5 "The
driver's door switch signal is not received

P.54C-474

<LH drive vehicles> or

P.54C-476

<RH drive vehicles>."

Normal condition is not displayed for item Nos.35
or 70. :

Replace the front-ECU.

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

Item 30

IG SW(IG1)

from ON to OFF

Item 70

FRONT ECU
ACK

SLEEP ACK or
NORMAL ACK

Item No.

Item name

Normal
condition

Item 32

DR DOOR SW

ON

Item 35

HD AUTO-CUT

OFF