Mitsubishi Galant 9G. Manual — part 838

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <2.4L ENGINE>

13A-794

STEP 2. Measure the power supply voltage at power
steering pressure switch connector B-31 by backprobing.
(1) Do not disconnect the connector B-31.
(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 measured voltage within the specified range?

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

STEP 3. Check harness connector B-31 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.

AK303881

1

AB

CONNECTOR: B-31

B-31 (B)

HARNESS
CONNECTOR:
COMPONENT SIDE

1

AK202987

B-31 HARNESS
CONNECTOR:
HARNESS SIDE

AC

AK303881

1

AB

CONNECTOR: B-31

B-31 (B)

HARNESS
CONNECTOR:
COMPONENT SIDE

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <2.4L ENGINE>

13A-795

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

− How to

Cope with Intermittent Malfunctions

P.00-14

.

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

STEP 5. Check harness connector B-31 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.

AK303804AB

MB991910

DATA LINK
CONNECTOR

MB991824

MB991827

AK303881

1

AB

CONNECTOR: B-31

B-31 (B)

HARNESS
CONNECTOR:
COMPONENT SIDE

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <2.4L ENGINE>

13A-796

STEP 6. Measure the power supply voltage at power
steering pressure switch harness side connector B-31.
(1) Disconnect the connector B-31 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.

AK303881

1

AB

CONNECTOR: B-31

B-31 (B)

HARNESS
CONNECTOR:
COMPONENT SIDE

AK202988

1

B-31 HARNESS
CONNECTOR:
COMPONENT SIDE

AC

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <2.4L ENGINE>

13A-797

STEP 7. Measure the power supply voltage at PCM
connector B-21 by using power plant ECU check harness
special tool MB991923.
(1) Disconnect the all PCM connectors and connect power

plant ECU check harness special tool MB991923 between
the separated connectors.

(2) Disconnect the power steering pressure switch connector

B-31.

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

AK303018

55

56

54 53 52 51

57

62 61 60 59 58

63

69 68 67 66 65 64

70

75 74 73 72 71

76

82 81 80 79 78 77

83

CONNECTOR: B-21

PCM

AB

HARNESS CONNECTOR:
COMPONENT SIDE

AIR CLEANER

B-21 (B)

AK202989

55

56

54 53 52 51

57

62 61 60 59 58

63

69 68 67 66 65 64

70

75 74 73 72 71

76

82 81 80 79 78 77

83

AB

POWER PLANT ECU
CHECK HARNESS CONNECTOR

MB991923

PCM