Mitsubishi Evolution X. Manual — part 291

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

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MULTIPORT FUEL INJECTION (MFI)

13A-141

STEP 11. Using scan tool MB991958, check data list item 8:
Manifold Absolute Pressure Sensor.
(1) Turn the ignition switch to the "ON" position.
(2) Set scan tool MB991958 to the data reading mode for item

8, Manifold Absolute Pressure Sensor.

• When altitude is 0 m (0 foot), 101 kPa (29.8 in.Hg).

• When altitude is 600 m (1,969 feet), 95 kPa (28.1 in.Hg).

• When altitude is 1,200 m (3,937 feet), 88 kPa (26.0

in.Hg).

• When altitude is 1,800 m (5,906 feet), 81 kPa (23.9

in.Hg).

(3) Start the engine.

• When the engine is idling, 31 − 45 kPa (9.1 − 13.3 in.Hg).

• When the engine is suddenly revved, manifold absolute

pressure varies.

(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

− How to

Cope with Intermittent Malfunctions

P.00-15

.

NO : Replace the ECM. When the ECM is replaced,

register the ID code. Refer to GROUP 42B, ID Code
Registration Necessity Judgment Table <Vehicles
with KOS>

P.42B-12

or GROUP 42C, ID Codes

Registration Judgment Table <Vehicles with WCM>

P.42C-9

. Then go to Step 12.

STEP 12. Test the OBD-II drive cycle.
(1) Carry out a test drive with the drive cycle pattern. Refer to

Diagnostic Function

− OBD-II Drive Cycle − Pattern 6

P.13A-9

.

(2) Check the diagnostic trouble code (DTC).
Q: Is DTC P0107 set?

YES : Retry the troubleshooting.
NO : The inspection is complete.

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

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MULTIPORT FUEL INJECTION (MFI)

13A-142

DTC P0108: Manifold Absolute Pressure Circuit High Input

.

AK604115

1

2

3 4 5 6 7 8 9 10 11 12 13 14 15 16

17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32

33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48

49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64

3

2

1

AC

MANIFOLD ABSOLUTE
PRESSURE SENSOR

BLUE

3

1

2

MANIFOLD ABSOLUTE PRESSURE SENSOR CIRCUIT

B-09

B-18

(MU802723)

44

45

46

ENGINE
CONTROL
MODULE

YELLO

W

-BLUE

BLA

CK-WHITE

AK704227

Connector: B-09

ECM

B-09 (GR)

AB

AK704238 AB

Manifold absolute
pressure sensor

Connector: B-18

B-18 (B)

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

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MULTIPORT FUEL INJECTION (MFI)

13A-143

CIRCUIT OPERATION

• A 5-volt voltage is supplied to the manifold abso-

lute pressure sensor power terminal (terminal No.
3) from ECM (terminal No. 44). The ground termi-
nal (terminal No. 2) is grounded with ECM (termi-
nal No. 46).

• A voltage that is proportional to the intake mani-

fold pressure is sent to the ECM (terminal No. 45)
from the manifold absolute pressure sensor out-
put terminal (terminal No. 1).

.

TECHNICAL DESCRIPTION

• The manifold absolute pressure sensor outputs a

voltage which corresponds to the intake manifold
pressure.

• The ECM checks whether this voltage is within a

specified range.

.

DESCRIPTIONS OF MONITOR METHODS

Manifold absolute pressure sensor output voltage is

out of specified range.

.

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

• Throttle position sensor

• Mass airflow sensor

• Intake air temperature sensor

• Barometric pressure sensor

.

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

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MULTIPORT FUEL INJECTION (MFI)

13A-144

DTC SET CONDITIONS

Logic Flow Chart

Check Condition

• 8 minutes or more have passed since the engine

starting sequence was completed, when the
engine coolant temperature at engine start is 0

° C

(32

° F) or lower.

Judgement Criterion

• Manifold absolute pressure sensor output voltage

has continued to be 4.6 volts [corresponding to a
manifold absolute pressure of 314 kPa (93.0
in.Hg)] or higher for 2 seconds.

.

FAIL-SAFE AND BACKUP FUNCTION

• None

.

OBD-II DRIVE CYCLE PATTERN

Refer to Diagnostic Function

− OBD-II Drive Cycle −

Pattern 23

P.13A-9

.

.

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

• Manifold absolute pressure sensor failed.

• Open manifold absolute pressure sensor circuit,

or connector damage.

• ECM failed.

Yes

Yes

Yes

Yes

No

No

No

No

Monitoring

conditions

Pressure

< 5kPa (1.5in.Hg)

Pressure

> 117kPa (34.6in.Hg)

Continuous

failure for 2secs

Malfunction

End

Good

Start

AK604313