Mitsubishi Montero (2004+). Manual — part 295

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

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MULTIPORT FUEL INJECTION (MFI)

13A-667

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CIRCUIT OPERATION

• A battery positive voltage is applied to the power

steering pressure switch output terminal (terminal
No. 1) from the PCM (terminal No. 47) via the
resistor in the PCM.

.

TECHNICAL DESCRIPTION

• The power steering pressure switch converts the

existence of a power steering load into a high/low
voltage, and inputs it into the PCM.

• When the steering wheel is turned, hydraulic

pressure rises. The power steering pressure
switch closes, and the applied battery positive
voltage will be grounded. With this, the power
steering pressure switch output voltage will fluc-
tuate between 12 volts and 0 volt.

• While driving with the steering wheel held

straight, the power steering pressure switch turns
"OFF".

• The PCM checks whether the power steering

pressure switch turns "OFF" or "ON" during driv-
ing.

.

DESCRIPTIONS OF MONITOR METHODS
Power steering pressure switch changes from off to

on more than 10 times for 1 second.

.

MONITOR EXECUTION
Continuous

.

MONITOR EXECUTION CONDITIONS (Other
monitor and Sensor)

Other Monitor (There is no temporary DTC stored

in memory for the item monitored below)

• Not applicable

Sensor (The sensor below is determined to be

normal)

• Engine coolant temperature sensor

.

AK200972

POWER
STEERING
OIL PUMP

POWER STEERING
PRESSURE SWITCH

AB

B-29(B)

CONNECTOR: B-29

AK201038

CONNECTOR: D-133

AC

PCM

D-133(GR)

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

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MULTIPORT FUEL INJECTION (MFI)

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DTC SET CONDITIONS

Logic Flow Chart

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Check Conditions

• Engine coolant temperature is higher than 30°C

(86

°F).

• Vehicle speed is higher than 50 km/h (31 mph).

Judgment Criteria

• The ON/OFF frequency of a power steering pres-

sure switch is 10 Hz or more for 20 seconds.

.

OBD-II DRIVE CYCLE PATTERN
None.

.

TROUBLESHOOTING HINTS (The most likely
causes for this code to be set are: )

• Power steering pressure switch failed.

• Incorrect power steering fluid level.

• Incorrect oil pump pressure.

• Harness damage in power steering pressure

switch circuit, 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

START

END

NO

NO

YES

YES

YES

NO

MALFUNCTION

GOOD

CONTINUOUS FAILURE

FOR 20secs

FREQUENCY > 10Hz

MONITORING

CONDITIONS

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MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

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MULTIPORT FUEL INJECTION (MFI)

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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 sensor 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.

STEP 2. Check the power steering fluid level.
Refer to GROUP 37A, On-Vehicle Service

− Fluid Level Check

P.37A-17

.

Q: Are there any abnormalities?

YES : Go to Step 3.
NO : Repair it. Then go to Step 7.

STEP 3. Check the power steering pressure switch.
Refer to GROUP 37A, On-Vehicle Service

− Power Steering

Pressure Switch Check

P.37A-20

.

Q: Are there any abnormalities?

YES : Go to Step 4.
NO : Replace the power steering pressure switch. Then go

to Step 7.

STEP 4. Check the oil pump pressure .
Refer to GROUP 37A, On-Vehicle Service

− Oil Pump Pressure

Test

P.37A-19

.

Q: Are there any abnormalities?

YES : Go to Step 5.
NO : Repair it. Then go to Step 7.

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AB

MB991911

MB991824

MB991827

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

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MULTIPORT FUEL INJECTION (MFI)

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STEP 5. Check connector B-29 at the power steering
pressure switch and connector D-133 at PCM for damage.
Q: Is the 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 7.

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1

AB

CONNECTOR: B-29

B-29(B)

HARNESS
CONNECTOR:
COMPONENT SIDE

AK200939

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

AB

CONNECTOR: D-133

HARNESS CONNECTOR:
COMPONENT SIDE

PCM

D-133(GR)