Mitsubishi Galant (2004+). Manual - part 985

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <2.4L ENGINE>

13A-757

Check Conditions 

• Engine coolant temperature is higher than 20°C 

(68

°F). 

• Drive for 4 seconds or more with the vehicle 

speed is 50 km/h (31 mph) or more. Stop the 
vehicle [vehicle speed is 1.5 km/h (1.0 mph) or 
less]. Repeat 10 times or more. 

Judgment Criteria 

• Power steering pressure switch continues to be 

"ON". 

.

OBD-II DRIVE CYCLE PATTERN
None.

.

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

• Power steering pressure switch failed. 

• 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

• MB991910: Main Harness A

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.

AK303804AB

MB991910

DATA LINK
CONNECTOR

MB991824

MB991827

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <2.4L ENGINE>

13A-758

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-759

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-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-760

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