Mitsubishi Galant (2004+). Manual - part 987

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <2.4L ENGINE>

13A-765

STEP 12. Check harness connector B-21 at PCM for 
damage. 

Q: Is the harness connector in good condition? 

YES : Go to Step 13. 
NO :  Repair or replace it. Refer to GROUP 00E, Harness 

Connector Inspection 

P.00E-2

. Then go to Step 14.

AK303018

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CONNECTOR: B-21

PCM

AB

HARNESS CONNECTOR: 
COMPONENT SIDE

AIR CLEANER

B-21 (B)

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

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MULTIPORT FUEL INJECTION (MFI) <2.4L ENGINE>

13A-766

STEP 13. Check for harness damage between power 
steering pressure switch connector B-31 (terminal No. 1) 
and PCM connector B-21 (terminal No. 78). 

Q: Is the harness wire in good condition? 

YES : Replace the PCM. Then go to Step 14.
NO :  Repair it. Then go to Step 14.

AK303881

1

AB

CONNECTOR: B-31

B-31 (B)

HARNESS 
CONNECTOR:
COMPONENT SIDE

AK303018

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CONNECTOR: B-21

PCM

AB

HARNESS CONNECTOR: 
COMPONENT SIDE

AIR CLEANER

B-21 (B)

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <2.4L ENGINE>

13A-767

STEP 14. 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 : The inspection is complete.
NO :  Retry the troubleshooting.

AK303804AB

MB991910

DATA LINK
CONNECTOR

MB991824

MB991827

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <2.4L ENGINE>

13A-768

DTC P0554: Power Steering Pressure Switch Circuit Intermittent

.

CIRCUIT OPERATION

• A battery positive voltage is applied to the power 

steering pressure switch output terminal (terminal 
No. 1) from the PCM (terminal No. 78) 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.

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AK303879

YELLO

W

POWERTRAIN
CONTROL
MODULE (PCM)

B-31

(MU801211)

POWER STEERING
PRESSURE SWITCH

78

1

Power Steering Pressure Switch Circuit

B-21

AK303880AB

CONNECTOR: B-31

POWER STEERING
PRESSURE SWITCH

B-31 (B)

AK303119

CONNECTOR: B-21

PCM

AB

AIR CLEANER

B-21