Mitsubishi Grandis. Manual — part 769

TROUBLESHOOTING

MULTIPORT FUEL INJECTION (MPI)

13A-327

STEP 14. Connector check: C-115 earth
connector.

Q: Is the check result normal?

YES :

Check and repair harness between C-111

engine-ECU <M/T> connector or
engine-A/T-ECU <A/T> connector and
C-115 earth connector.

a. Check and repair harness between

C-111 (terminal No. 33) engine-ECU
<M/T> connector or engine-A/T-ECU
<A/T> connector and C-115 (terminal
No. 10) earth connector.

b. Check and repair harness between

C-111 (terminal No. 42) engine-ECU
<M/T> connector or engine-A/T-ECU
<A/T> connector and C-115 (terminal
No. 9) earth connector.

• Check earthing line for open circuit

and damage.

NO :

Repair

AK305625AB

Connector: C-111

<L.H. drive vehicles>

<R.H. drive vehicles>

C-111 (GR)

C-111 (GR)

Harness side connector

31

32

33

34

35

36

37

38

39

40

41

42

43

44

45

46

47

48

49

52

53

54

55

56

57

58

50

51

AK305626

Connector: C-115

<L.H. drive vehicles>

<R.H. drive vehicles>

C-115

C-115

Harness side connector

AB

4 3

2 1

11 10 9

5

6

7

8

TROUBLESHOOTING

MULTIPORT FUEL INJECTION (MPI)

13A-328

Inspection Procedure 23: Fuel Pump System

AK305579

1 2 3

4 5

3 4

1 2

3 4

1 2

1

2

3

5

6 7 8 9

4

20

21 22

232425

2627

10111213

14 15

16 1718

19

1 2 3

4 5 6

Fusible link (26)

W

W

M

24

15A

8

7.5A

J/B

Ignition switch

Relay box

Fuel
pump
relay (1)
C-216

Fuel
pump
relay (2)
C-214

2

3

1

14

11

5

4

9

Fuel pump and gauge unit (main) circuit

OFF

4

2

2

L-B

O

C-125

C-203

O

C-202

6

1

3

OFF

ON

ON

1

2

4

3

C-214

C-216

16

C-210

D-28

D-28

C-205

B

B

B

B

B-L

B-L

B

B

G

G

C-18

6

C-205

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

AB

C-110

(MU803802)

Engine-ECU <M/T> or
engine-A/T-ECU <A/T>

4

NOTE

*1: R.H. drive vehicles
*2: L.H. drive vehicles

*1

*2

Fuel pump
and gauge
unit (main)

D-15
(MU802058)

C-307

IG2

ST

R

LOCK

ACC

IG1

TROUBLESHOOTING

MULTIPORT FUEL INJECTION (MPI)

13A-329

OPERATION

• The battery voltage is applied to the fuel pump

relay (1) (terminal No. 3) form the ignition switch
and is earthed to the vehicle body from the fuel
pump relay (1) (terminal No. 2).

• The battery voltage is applied to the fuel pump

relay (1) (terminal No. 4) and to the fuel pump
relay (2) (terminal No. 1) from the fuel pump relay
(1) (terminal No. 1).

• The battery voltage is applied to the fuel pump

relay (2) (terminal No. 3) from the ignition switch.
The engine-ECU <M/T> or engine-A/T-ECU
(terminal No. 16) makes the power transistor in
the unit be in ON position and makes currents go
on the fuel pump relay (2) coil, and that makes
the relay be in ON position.

• When the fuel pump relay (2) is in ON position,

the battery voltage is supplied to the fuel pump
(low pressure) from the fuel pump relay (2)
(terminal No. 4).

FUNCTION

• When the ignition switch ON signal is input to the

engine-ECU <M/T> or engine-A/T-ECU <A/T>,
the engine-ECU <M/T> or engine-A/T-ECU
<A/T> places the fuel pump relay in the ON
position. Accordingly, the battery voltage is
supplied to the fuel pump.

PROBABLE CAUSE

• Failed fuel pump relay

• Failed fuel pump

• Open/short circuit in fuel pump drive circuit or

loose connector contact

• Failed engine-ECU <M/T>

• Failed engine-A/T-ECU <A/T>

DIAGNOSIS PROCEDURE

STEP 1. Connector check: C-216 fuel pump relay
(1) connector and C-214 fuel pump relay (2)
connector

Q: Is the check result normal?

YES :

Go to Step 2 .

NO :

Repair or replace.

STEP 2. Check fuel pump relay.

• Fuel pump relay, continuity check (Refer to

P.13A-389

).

Q: Is the check result normal?

YES :

Go to Step 3 .

NO :

Replace fuel pump relay.

AK305633

2 1

3

4

AB

Connectors: C-214, C-216

C-214

Harness side
connector

C-216

C-214

Relay box’s
triangle marks

C-216

<L.H. drive vehicles>

<R.H. drive vehicles>

TROUBLESHOOTING

MULTIPORT FUEL INJECTION (MPI)

13A-330

STEP 3. Perform resistance measurement at
C-216 fuel pump relay (1) connector.

• Remove relay, and measure at junction block

side.

• Resistance between terminal No. 2 and earth.

OK: 2

Ω or less

Q: Is the check result normal?

YES :

Go to Step 4 .

NO :

Check intermediate connector C-205, and

repair if necessary. If intermediate
connector is normal, check and repair
harness between C-216 (terminal No. 2)
fuel pump relay (1) connector and body
earth.

• Check earthing line for open circuit

and damage.

STEP 4. Perform voltage measurement at C-216
fuel pump relay (1) connector.

• Remove relay, and measure at junction block

side.

• Ignition switch: ON

• Voltage between terminal No. 3 and earth.

OK: System voltage

Q: Is the check result normal?

YES :

Go to Step 6 .

NO :

Go to Step 5 .

AK305635

2 1

3

4

AB

Connector: C-216

C-216

Harness side
connector

C-216

Relay box’s
triangle marks

<L.H. drive vehicles>

<R.H. drive vehicles>

AK305635

2 1

3

4

AB

Connector: C-216

C-216

Harness side
connector

C-216

Relay box’s
triangle marks

<L.H. drive vehicles>

<R.H. drive vehicles>