Mitsubishi Grandis. Manual — part 68

SYMPTOM PROCEDURES

SMART WIRING SYSTEM (SWS) NOT USING SWS MONITOR

54B-269

Step 7. Retest the system.

Check that the ignition key cylinder illumination lamp
illuminates/extinguishes 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 ETACS-ECU.

SEAT BELT WARNING LAMP

Inspection Procedure L-1: The seat belt warning lamp does not flash normally.

CAUTION

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

COMMENTS ON TROUBLE SYMPTOM

The ETACS-ECU flashes the seat belt warning lamp
in accordance with the input signal from the ignition
switch (IG1).
If it does not flash normally, these input signal
circuit(s) or the ETACS-ECU may be defective.

POSSIBLE CAUSES

• Malfunction of the ETACS-ECU

• Damaged harness wires and connectors

DIAGNOSTIC PROCEDURE

Step 1. MUT-III diagnosis code
When the ignition switch is turned to the LOCK
(OFF) position, check that the ETACS-ECU does not
set the diagnosis code.

Q: Is the diagnosis code set?

YES :

Refer to diagnosis code chart

P.54B-29

.

NO :

Go to Step 2.

Step 2. Check the seat belt switch, where the seat
belt warning lamp does not function normally.

Q: Which seat belt switch does not activate the seat

belt warning lamp?
Driver's seat belt :

Go to Step 3

Passenger's seat belt :

Go to Step 4.

Step 3. Pulse check
Check the input signals, which are related to the seat
belt warning lamp.

• Ignition switch: ON

• Driver’s seat belt switch: ON

OK: The MUT-III sounds or the voltmeter
needle fluctuates.

Q: Are the check result normal?

Seat Belt Warning Lamp Function

ETACS-
ECU

· SPEED SIGNAL
· DRIVER'S SEAT BELT SWITCH

COMBINATION
METER

CAN COMMUNICATION LINE
(CAN_L LINE)

CAN COMMUNICATION LINE
(CAN_H LINE)

INPUT SIGNAL

INPUT SIGNAL

· IGNITION SWITCH (IG1)
· PASSENGER'S SEAT BELT SWITCH

System switch

Check condition

Ignition switch (IG1)

When turned from ACC
to ON

Driver’s seat belt switch ON

SYMPTOM PROCEDURES

SMART WIRING SYSTEM (SWS) NOT USING SWS MONITOR

54B-270

All the signals are received normally. :

Go to Step

5.

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

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

P.54B-420

."

Driver’s seat belt switch signal is not received :

Refer to inspection procedure Q-19 "The
driver's seat belt switch signal is not
received

P.54C-537

<LH drive vehicles> or

P.54C-540

<RH drive vehicles>."

Step 4. Pulse check
Check the input signals, which are related to the seat
belt warning lamp.

• Ignition switch: ON

• Passenger’s seat belt switch and seat occupancy

sensor: ON

OK: The MUT-III sounds or the voltmeter
needle fluctuates.

Q: Are 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 Q-2 "The
ignition switch (IG1) signal is not received

P.54B-420

."

Passenger’s seat belt switch signal is not received
:

Refer to inspection procedure Q-20 "The
front passenger's seat belt switch signal is
not received

P.54C-543

<LH drive vehicles>

or

P.54C-546

<RH drive vehicles>."

Step 5. Pulse check
Check the input signals below which are related to
the seat belt warning lamp.

OK: The MUT-III sounds or the voltmeter
needle fluctuates.

Q: Is the check result normal?

YES :

Go to Step 6.

NO :

Refer to inspection procedure Q-25 "The
vehicle speed signal is not received

P.54B-529

."

Step 6. Retest the system.
Check that the seat belt warning lamp work 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 ETACS-ECU.

System switch

Check condition

Ignition switch (IG1)

When turned from ACC
to ON

Passenger’s seat belt
switch and seat
occupancy sensor

ON

System switch

Check condition

Vehicle speed signal

When the vehicle speed
has reached 10 km/h or
more.

SYMPTOM PROCEDURES

SMART WIRING SYSTEM (SWS) NOT USING SWS MONITOR

54B-271

HEADLAMP AND TAIL LAMP

Inspection Procedure M-1: The tail/stop lamps 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 all the tail/stop lamps do not illuminate, the tail
lamp 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

DIAGNOSTIC PROCEDURE

Step 1. Pulse check
Check the input signal from the tail lamp switch.

OK: The MUT-III sounds or the voltmeter
needle fluctuates.

Q: Is the check result 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

BATTERY

FRONT-ECU

TAIL LAMP
RELAY

RELAY
BOX

INPUT SIGNAL

· HEADLAMP AUTOMATIC
SHUTDOWN
· TAIL LAMP SWITCH

· REAR COMBINATION
LAMP (LH)

· LICENSE PLATE LAMP
· POSITION LAMP (LH)

· REAR COMBINATION
LAMP (RH)

· POSITION LAMP (RH)

Tail Lamp Relay Circuit

System switch

Check condition

Ignition switch (IG1)

When turned from ACC
to ON

Tail lamp switch

When the lighting switch
is turned to the TAIL
position

SYMPTOM PROCEDURES

SMART WIRING SYSTEM (SWS) NOT USING SWS MONITOR

54B-272

All the signals are received normally. :

Go to Step

2.

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

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

P.54B-420

."

The tail lamp switch signal is not received. :

Refer

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

P.54B-438

."

Step 2. Connector check: A-14X front-ECU
connector

Q: Is the check result normal?

YES :

Go to Step 3.

NO :

Repair the defective connector.

Step 3. Voltage measurement at A-14X front-ECU
connector.

(1) Remove the front-ECU, and measure at the relay

box side.

(2) Voltage between A-14X front-ECU connector

terminal No.5 and body earth

OK: System voltage

Q: Is the check result normal?

YES :

Go to Step 5.

NO :

Go to Step 4.

Step 4. Check the wiring harness between A-14X
front-ECU connector terminal No.5 and the
fusible link (26).

• Check the power supply line for open circuit.

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 :

Repair the wiring harness.

Step 5. Retest the system.
Check that the tail/stop lamps 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.

AC311521AB

Connector: A-14X

Relay box side

AC311521AB

Connector: A-14X

Relay box side

AC310507CE

Connector A-14X
(Relay box side)

AC311521AB

Connector: A-14X

Relay box side