Mitsubishi Montero (2004+). Manual — part 293

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

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MULTIPORT FUEL INJECTION (MFI)

13A-659

• Open or shorted power steering pressure switch

circuit, harness damage, or connector damage.

• PCM failed.

DIAGNOSIS

Required Special Tools:

• MB991958: Scan Tool (MUT-III Sub Assembly)

• MB991824: V.C.I.

• MB991827: USB Cable

• MB991911: Main Harness B

STEP 1. Using scan tool MB991958, check data list item 27:
Power Steering Pressure Switch.

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) Start the engine and run at idle.
(3) Set scan tool MB991958 to the data reading mode for item

27, Power Steering Pressure Switch.

• If the steering wheel is not turned while idling, "OFF" will

be displayed.

• If the steering wheel is turned while idling, "ON" will be

displayed.

(4) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the switch operating properly?

YES : It can be assumed that this malfunction is

intermittent. Refer to GROUP 00, How to Use
Troubleshooting/Inspection Service Points

P.00-6

.

NO : Go to Step 2.

AK302970

AB

MB991911

MB991824

MB991827

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

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MULTIPORT FUEL INJECTION (MFI)

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STEP 2. Measure the power supply voltage at power
steering pressure switch connector B-29 by backprobing.
(1) Do not disconnect the connector B-29.
(2) Start the engine and run at idle.

(3) Measure the voltage between terminal No. 1 and ground by

backprobing.

• When steering wheel is not turned, voltage should be

battery positive voltage.

• When steering wheel is turned, voltage should be 1 volt

or less.

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

YES : Go to Step 3.
NO : Go to Step 5.

STEP 3. Check harness connector B-29 at power steering
pressure switch for damage.
Q: Is the harness connector in good condition?

YES : Go to Step 4.
NO : Repair or replace it. Refer to GROUP 00E, Harness

Connector Inspection

P.00E-2

. Then go to Step 14.

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CONNECTOR: B-29

B-29(B)

HARNESS
CONNECTOR:
COMPONENT SIDE

AKX01551

1

AC

B-29 HARNESS
CONNECTOR:
HARNESS SIDE

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CONNECTOR: B-29

B-29(B)

HARNESS
CONNECTOR:
COMPONENT SIDE

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

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MULTIPORT FUEL INJECTION (MFI)

13A-661

STEP 4. Using scan tool MB991958, check data list item 27:
Power Steering Pressure Switch.

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) Start the engine and run at idle.
(3) Set scan tool MB991958 to the data reading mode for item

27, Power Steering Pressure Switch.

• If the steering wheel is not turned while idling, "OFF" will

be displayed.

• If the steering wheel is turned while idling, "ON" will be

displayed.

(4) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the switch operating properly?

YES : It can be assumed that this malfunction is intermittent.

Refer to GROUP 00, How to Use
Troubleshooting/Inspection Service Points

P.00-6

.

NO : Replace the PCM. Then go to Step 14.

STEP 5. Check harness connector B-29 at power steering
pressure switch for damage.
Q: Is the harness connector in good condition?

YES : Go to Step 6.
NO : Repair or replace it. Refer to GROUP 00E, Harness

Connector Inspection

P.00E-2

. Then go to Step 14.

AK302970

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MB991911

MB991824

MB991827

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CONNECTOR: B-29

B-29(B)

HARNESS
CONNECTOR:
COMPONENT SIDE

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

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MULTIPORT FUEL INJECTION (MFI)

13A-662

STEP 6. Measure the power supply voltage at power
steering pressure switch harness side connector B-29.
(1) Disconnect the connector B-29 and measure at the harness

side.

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

(3) Measure the voltage between terminal No. 1 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 11.
NO : Go to Step 7.

STEP 7. Measure the power supply voltage at PCM
connector D-133 by backprobing.
(1) Do not disconnect the PCM connector D-133.
(2) Disconnect the power steering pressure switch connector

B-29.

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

(4) Measure the voltage between terminal No. 47 and ground

by backprobing.

• Voltage should be between battery positive voltage.

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

present?
YES : Go to Step 8.
NO : Go to Step 9.

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CONNECTOR: B-29

B-29(B)

HARNESS
CONNECTOR:
COMPONENT SIDE

AKX01429AC

1

B-29 HARNESS
CONNECTOR:
COMPONENT SIDE

AK200939

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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

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CONNECTOR: D-133

HARNESS CONNECTOR:
COMPONENT SIDE

PCM

D-133(GR)

3132

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35363738394041 42 43
444546474849
5253

545556

57 58

50 51

D-133 HARNESS
CONNECTOR:
HARNESS SIDE

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