Mitsubishi Grandis. Manual - part 127

INPUT SIGNAL PROCEDURES

SMART WIRING SYSTEM (SWS) NOT USING SWS MONITOR

54B-505

YES : 

Go to Step 2.

NO : 

Repair the defective connector.

Step 2. Check the seat belt switch (LH).
Refer to GROUP 52A 

− Front seat belt 

P.52A-36

.

Q: Is the check result normal?

YES : 

Go to Step 3.

NO : 

Replace the inner seat belt (front 
passenger's side).

Step 3. Connector check: D-26-1 seat occupancy 
sensor connector

Q: Is the check result normal?

YES : 

Go to Step 4.

NO : 

Repair the defective connector.

Step 4. Check the seat occupancy sensor.
Refer to GROUP 52A 

− Front seat 

P.52A-22

.

Q: Is the check result normal?

YES : 

Go to Step 5.

NO : 

Replace the seat occupancy sensor.

Step 5. Resistance measurement at the D-26-1 
seat occupancy sensor connector.

(1) Disconnect the connector, and measure at the 

wiring harness side.

(2) Resistance between D-26-1 seat occupancy 

sensor connector terminal No.3 and body earth

OK: 2 

Ω or less

Q: Is the check result normal?

YES : 

Go to Step 7.

NO : 

Go to Step 6.

Step 6. Check the wiring harness between D-26-1 
seat occupancy sensor connector terminal No.3 
and body earth.

• Check the earth wires for open circuit.

Q: Is the check result normal?

YES : 

Replace the inner seat belt (front 

passenger's side).

NO : 

Repair the wiring harness.

Step 7. Connector check: C-220 ETACS-ECU 
connector

Q: Is the check result normal?

AC313233

Connector: D-26-1

AB

Harness side

<LHD>

AC313233

Connector: D-26-1

AB

Harness side

<LHD>

AC301541IB

Connector D-26-1
(Harness side)

AC313233

Connector: D-26-1

AB

Harness side

<LHD>

AC310626

Connector: C-220 <LHD>

Junction block (Rear view)

AE

Harness side

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INPUT SIGNAL PROCEDURES

SMART WIRING SYSTEM (SWS) NOT USING SWS MONITOR

54B-506

YES : 

Go to Step 8.

NO : 

Repair the defective connector.

Step 8. Check the wiring harness from D-26-1 
seat occupancy sensor connector terminal No.1 
to C-220 ETACS-ECU connector terminal No.29.

NOTE: 

Prior to the wiring harness inspection, check 
intermediate connector C-16, and repair if necessary.

• Check the input line for open circuit.

Q: Is the check result normal?

YES : 

Go to Step 9.

NO : 

Repair the wiring harness or replace the 
inner seat belt (front passenger's side).

Step 9. Retest the system.
Check that the front passenger's seat belt switch 
signal is received normally.

Q: Is the check result normal?

YES : 

Intermittent malfunction (Refer to GROUP 

00 

− How to Cope with Intermittent 

Malfunction 

P.00-5

).

NO : 

Replace the ETACS-ECU.

AC310626

Connector: C-220 <LHD>

Junction block (Rear view)

AE

Harness side

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AC313233

Connector: D-26-1

AB

Harness side

<LHD>

AC310615

AE

Connector: C-16 <LHD>

INPUT SIGNAL PROCEDURES

SMART WIRING SYSTEM (SWS) NOT USING SWS MONITOR

54B-507

Inspection Procedure Q-20: The front passenger's seat belt switch signal is not received. <RH drive 
vehicles>

CAUTION

Whenever the ECU is replaced, ensure that the 
input signal circuit is normal.

COMMENTS ON TROUBLE SYMPTOM

Input signal from the passenger’s seat belt switch is 
used to operate the seat belt warning buzzer function 
and seat belt warning lamp. If the signal is abnormal, 
the seat belt warning buzzer function and seat belt 
warning lamp will not work normally.

POSSIBLE CAUSES

• Malfunction of the passenger’s seat belt switch

• Malfunction of the seat occupancy sensor

• Malfunction of the ETACS-ECU

• Damaged harness wires and connectors

DIAGNOSTIC PROCEDURE

Step 1. Connector check: D-23 seat belt switch 
(LH) connector

Q: Is the check result normal?

ETACS-
ECU

SEAT
BELT
SWITCH
(LH)

SEAT
OCCUPANCY
SENSOR

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

Passenger's Seat Belt Switch Input Circuit <RHD>

AC312058

AD

Connector: D-23 <RHD>

INPUT SIGNAL PROCEDURES

SMART WIRING SYSTEM (SWS) NOT USING SWS MONITOR

54B-508

YES : 

Go to Step 2.

NO : 

Repair the defective connector.

Step 2. Check the seat belt switch (LH).
Refer to GROUP 52A 

− Front seat belt 

P.52A-36

.

Q: Is the check result normal?

YES : 

Go to Step 3.

NO : 

Replace the inner seat belt (front 
passenger's side).

Step 3. Connector check: D-23-1 seat occupancy 
sensor connector

Q: Is the check result normal?

YES : 

Go to Step 4.

NO : 

Repair the defective connector.

Step 4. Check the seat occupancy sensor.
Refer to GROUP 52A 

− Front seat 

P.52A-22

.

Q: Is the check result normal?

YES : 

Go to Step 5.

NO : 

Replace the seat occupancy sensor.

Step 5. Resistance measurement at the D-23-1 
seat occupancy sensor connector.

(1) Disconnect the connector, and measure at the 

wiring harness side.

(2) Resistance between D-23-1 seat occupancy 

sensor connector terminal No.3 and body earth

OK: 2 

Ω or less

Q: Is the check result normal?

YES : 

Go to Step 7.

NO : 

Go to Step 6.

Step 6. Check the wiring harness between D-23-1 
seat occupancy sensor connector terminal No.3 
and body earth.

• Check the earth wires for open circuit.

Q: Is the check result normal?

YES : 

Replace the inner seat belt (front 

passenger's side).

NO : 

Repair the wiring harness.

Step 7. Connector check: C-220 ETACS-ECU 
connector

Q: Is the check result normal?

AC313233

Connector: D-23-1

AC

Harness side

<RHD>

AC313233

Connector: D-23-1

AC

Harness side

<RHD>

AC301541IC

Connector D-23-1
(Harness side)

AC313233

Connector: D-23-1

AC

Harness side

<RHD>

AC310620

Connector: C-220 <RHD>

Junction block (Rear view)

AD

Harness side

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