Mitsubishi Galant 9G. Manual — part 837

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <2.4L ENGINE>

13A-790

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, read the immobilizer
diagnostic trouble code (DTC).

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) Turn the ignition switch to the "ON" position.
(3) Read the immobilizer-DTC.
(4) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the immobilizer-DTC set?

YES : Refer to GROUP 54A, Ignition Switch and

Immobilizer System

− Diagnostic Trouble Code Chart

P.54A-12

.

NO : If DTC P0513 is output again after the MFI-DTC has

been erased, replace the PCM. Then check that the
DTC P0513 does not reset.

AK303804AB

MB991910

DATA LINK
CONNECTOR

MB991824

MB991827

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <2.4L ENGINE>

13A-791

DTC P0551: Power Steering Pressure Switch Circuit Range/Performance

.

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.

1

52

51

53 54 55 56

57

58 59 60 61 62

63

64 65 66 67 68 69

70

71 72 73 74 75

76

77 78 79 80 81 82

83

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

AC

AIR CLEANER

B-21(B)

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <2.4L ENGINE>

13A-792

• 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 0 and 12 volts.

• 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 stays on during

specified go/stop operations.

.

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

.

DTC SET CONDITIONS
Logic Flow Chart

YES

NO

NO

NO

MONITORING

CONDITIONS

END

MALFUNCTION

GOOD

START

POWER STEERING

SWITCH = "ON"

YES

GO/STOP OPERATION

FOR SPECIFIED TIMES

YES

AK302169

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <2.4L ENGINE>

13A-793

.

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

− How to

Cope with Intermittent Malfunctions

P.00-14

.

NO : Go to Step 2.

AK303804AB

MB991910

DATA LINK
CONNECTOR

MB991824

MB991827