Mitsubishi Grandis. Manual - part 202

SYMPTOM PROCEDURES

SMART WIRING SYSTEM (SWS) USING SWS MONITOR

54C-270

Step 8. Check the wiring harness from C-221 
ETACS-ECU connector terminal Nos.69 and 71 to 
C-308 key cylinder illumination lamp connector 
terminal Nos.1 and 2.

• Check the input and output lines for open circuit.

Q: Is the check result normal?

YES : 

Go to Step 9.

NO : 

Repair the wiring harness.

Step 9. 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.

AC310626

Connector: C-221

Junction block (Rear view)

<LHD>

AC

51

52

53

54

55

56

57

58

59

60

61

62

63

64

65

66

67

68

69

70

71

72

73

74

Harness side

C-221(GR)

AC310620

Connector: C-221

Junction block 
(Rear view)

<RHD>

AC

51

52

53

54

55

56

57

58

59

60

61

62

63

64

65

66

67

68

69

70

71

72

73

74

Harness side

C-221(GR)

AC310153AD

Connector: C-308 <LHD>

Harness side

AC310183

AD

Connector: C-308 <RHD>

Harness side

SYMPTOM PROCEDURES

SMART WIRING SYSTEM (SWS) USING SWS MONITOR

54C-271

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. SWS monitor data list.

Check the SWS communication signal, which are 
related to the seat belt warning lamp.

<Selected item> ETACS ECU

• Ignition switch: ON

OK: Normal condition is displayed.

Q: Is the check result normal?

YES : 

Go to Step 2.

NO : 

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

P.54C-460

."

Step 2. ETACS switch data by using the SWS 
monitor

Check the ETACS-ECU input signal related to the 
seat belt warning lamp function.

• Ignition switch: ON

• Driver's seat belt switch: ON (Unfastened)

• Passenger’s seat belt switch: ON (Unfastened)

• Seat occupancy sensor: ON (Seat occupied)

OK: Normal conditions are displayed for all 
the items

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

Item No.

Item name

Normal condition

Item 30

IG SW(IG1)

ON

Item No.

Item name

Normal condition

Item 12

SEAT BELT SW

ON

Item 43

As.SeatBeltSW

ON

SYMPTOM PROCEDURES

SMART WIRING SYSTEM (SWS) USING SWS MONITOR

54C-272

Normal conditions are displayed for all the items : 

Go to Step 3.

Normal condition is not displayed for item No.12. : 

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>."

Normal condition is not displayed for item No.43. : 

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

P.54C-546

 <LH drive vehicles> 

or 

P.54C-543

 <RH drive vehicles>."

Step 3. ETACS ANALOG data by using the SWS 
monitor.

Check the ETACS-ECU input signal related to the 
seat belt warning lamp function.

• Set the simulated vehicle speed at approximately 

10km/h.

OK: Normal condition is displayed.

Q: Is the check result normal?

YES : 

Go to Step 4.

NO : 

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

P.54C-568

."

Step 4. Retest the system.

Check that the seat belt warning lamp flashes 
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.

Item No.

Item name

Normal condition

Item 03

SPEED SENSOR

8 

− 10 km/h

SYMPTOM PROCEDURES

SMART WIRING SYSTEM (SWS) USING SWS MONITOR

54C-273

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

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?

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

· LICENCE PLATE LAMP
· POSITION LAMP (LH)
· TAIL/STOP LAMP (LH)

· POSITION LAMP (RH)
· TAIL/STOP LAMP (RH)

Tail Lamp Relay Circuit