Mitsubishi Montero (2004+). Manual - part 297

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI)

13A-675

STEP 1. Using scan tool MB991958, check data list item 
9A: Throttle Position Sensor (main) Mid Opening Learning 
Value.

CAUTION

To prevent damage to scan tool MB991958, always turn the 
ignition switch to the "LOCK"(OFF) position before con-
necting or disconnecting scan tool MB991958.
(1) Connect scan tool MB991958 to the data link connector.
(2) Turn the ignition switch to the "ON" position.
(3) Set scan tool MB991958 to the data reading mode for item 

9A, Throttle position sensor (main) mid opening learning 
value.

• Check that it is 4 volts or less.

(4) Turn the ignition switch to the "LOCK"(OFF) position.
Q: Is voltage 4 volts or less?

YES : Go to Step 2.
NO :  Replace the throttle body ASSY. Then go to Step 17.

STEP 2. Check connector B-23X at throttle actuator control 
motor relay for damage.
Q: Is the connector in good condition?

YES : Go to Step 3.
NO :  Repair or replace it. Refer to GROUP 00E, Harness 

Connector Inspection 

P.00E-2

. Then go to Step 17.

AK302970

AB

MB991911

MB991824

MB991827

AK201172

2 1

3

4

B-23X

AB

CONNECTOR: B-23X

HARNESS 
CONNECTOR: 
COMPONENT SIDE

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI)

13A-676

STEP 3. Check the throttle actuator control motor relay.
(1) Remove the throttle actuator control motor relay.

(2) Check for continuity between the throttle actuator control 

motor relay terminal No. 2 and No. 4.

• There should be continuity (approximately 70 ohms).

(3) Use jumper wires to connect throttle actuator control motor 

relay terminal No. 4 to the positive battery terminal and 
terminal No. 2 to the negative battery terminal.

(4) Check the continuity between the throttle actuator control 

motor relay terminal No. 1 and No. 3 while connecting and 
disconnecting the jumper wire at the negative battery 
terminal.

• Should be less than 2 ohms. (Negative battery terminal 

connected.)

• Should be open loop. (Negative battery terminal discon-

nected.)

(5) Install the throttle actuator control motor relay.
Q: Is the resistance normal?

YES : Go to Step 4.
NO :  Replace the throttle actuator control motor relay.       

Then go to Step 17.

AK201172

2 1

3

4

B-23X

AB

CONNECTOR: B-23X

HARNESS 
CONNECTOR: 
COMPONENT SIDE

1

2

3

4

AK201380AC

THROTTLE ACTUATOR 
CONTROL MOTOR RELAY
SIDE CONNECTOR

1

2

3

4

AK201381

THROTTLE ACTUATOR 
CONTROL MOTOR RELAY
SIDE CONNECTOR

AC

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI)

13A-677

STEP 4. Measure the power supply voltage at throttle 
actuator control motor relay harness side connector B-23X
(1) Disconnect the connector B-23X and measure at the 

harness side.

(2) Measure the voltage between terminal No. 3 and ground.

• Voltage should be battery positive voltage.

Q: Is battery positive voltage (approximately 12 volts) 

present?
YES : Go to Step 5.
NO :  Check harness connector A-03 at intermediate 

connector for damage, and repair or replace as 
required. Refer to GROUP 00E, Harness Connector 
Inspection 

P.00E-2

. If intermediate connector A-03 is 

in good condition, repair it because of open circuit or 
short circuit to ground between fusible link (5) and 
throttle actuator control motor relay connector B-23X 
(terminal No. 3). Then go to Step 17.

STEP 5. Measure the power supply voltage at throttle 
actuator control motor relay harness side connector 
B-23X.
(1) Disconnect the connector B-23X and measure at the 

harness side.

(2) Turn the ignition switch to the "ON" position.

(3) Measure the voltage between terminal No. 4 and ground.

• Voltage should be battery positive voltage.

(4) Turn the ignition switch to the "LOCK"(OFF) position.
Q: Is battery positive voltage (approximately 12 volts) 

present?
YES : Go to Step 7.
NO :  Go to Step 6.

AK201172

2 1

3

4

B-23X

AB

CONNECTOR: B-23X

HARNESS 
CONNECTOR: 
COMPONENT SIDE

2 1

3

4

AK201382AC

B-23X HARNESS
CONNECTOR:
COMPONFNT SIDE

AK201172

2 1

3

4

B-23X

AB

CONNECTOR: B-23X

HARNESS 
CONNECTOR: 
COMPONENT SIDE

2 1

3

4

AK201383

B-23X HARNESS
CONNECTOR:
COMPONFNT SIDE

AC

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI)

13A-678

STEP 6. Check connector B-22X at MFI relay for damage.
Q: Is the connector in good condition?

YES : Repair harness wire between MFI relay connector 

B-22X (terminal No. 1) and throttle actuator control 
motor relay connector B-23X (terminal No. 4) 
because of open circuit or short circuit to ground. 
Then go to Step 17.

NO :  Repair or replace it. Refer to GROUP 00E, Harness 

Connector Inspection 

P.00E-2

. Then go to Step 17.

STEP 7. Measure the power supply voltage at PCM harness 
side connector D-132.
(1) Disconnect the connector D-132 and measure at the 

harness side.

(2) Turn the ignition switch to the "ON" position.

(3) Measure the voltage between terminal No. 15 and ground.

• Voltage should be battery positive voltage.

(4) Turn the ignition switch to the "LOCK"(OFF) position.
Q: Is battery positive voltage (approximately 12 volts) 

present?
YES : Go to Step 8.
NO :  Repair harness wire between throttle actuator control 

motor relay connector B-23X (terminal No. 2) and 
PCM connector D-132 (terminal No. 15) because of 
open circuit or short circuit to ground. Then go to Step 
17.

AK200951

2 1

3

4

B-22X

AB

CONNECTOR: B-22X

HARNESS 
CONNECTOR: 
COMPONENT SIDE

AK200938

2

3

4

5

6

7

8

9

1

10

14

15

16

17

18

19

20

21

22

23

24

25

26

27

11

12

13

AB

CONNECTOR: D-132

HARNESS CONNECTOR: 
COMPONENT SIDE

PCM

D-132(GR)

2

3

4

5

6

7

8

9

1

10

14

15

16

17

18

19

20

21

22

23

24

25

26

27

11

12

13

AK201447

D-132 HARNESS 
CONNECTOR: 
COMPONENT SIDE

AB