Mitsubishi Galant 9G. Manual — part 1153

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <3.8L ENGINE>

13B-912

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 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) After the DTC has been deleted, read the DTC again.
(4) Turn the ignition switch to the "LOCK"(OFF) position.
Q: Is DTC P01602 set?

YES : Replace the PCM.
NO : 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

.

AC305412

AB

MB991910

DATA LINK

CONNECTOR

MB991824

MB991827

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <3.8L ENGINE>

13B-913

DTC P1603: Battery Backup Line Malfunction

.

RED-WHITE

WHITE

WHITE

BATTERY

42

BATTERY
BACKUP

POWERTRAIN
CONTROL
MODULE (PCM)

Battery Backup Circuit

B-20

9

20A

RELAY
BOX

22

21

23 24 25

26 27 28 29

30 31 32 33 34

35 36 37 38

39 40 41 42 43

AK400898

AK303085

CONNECTOR: B-20

PCM

AB

AIR CLEANER

B-20

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <3.8L ENGINE>

13B-914

TECHNICAL DESCRIPTION

• The PCM checks the open circuit of battery

backup line.

NOTE: When the system detects an open circuit in
the battery backup line, it makes 1 failure judgment
of other diagnostic trouble codes (DTCs).

.

DESCRIPTIONS OF MONITOR METHODS

Battery backup line voltage is under specified value.

.

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)

• Not applicable

.

DTC SET CONDITIONS
Logic Flow Chart

.

Check Conditions

• Engine starting sequence was completed.

• Battery positive voltage is higher than 10 volts.

Judgement Criteria

• Battery backup line voltage has continued to be 6

volts or lower for 2 seconds.

.

START

MONITORING
CONDITIONS

CIRCUIT VOLTAGE

MALFUNCTION

CONTINUOUS

FAILURE FOR 2secs

NO

YES

YES

NO

< 6V

END

GOOD

NO

Yes

AK302411

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <3.8L ENGINE>

13B-915

OBD-II DRIVE CYCLE PATTERN

None.

.

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

• Open or shorted battery backup line, 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

• MB991923: Power Plant ECU Check Harness

STEP 1. Using scan tool MB991958, read the 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) Erase the DTC.
(4) Start the engine and run it at idle.
(5) Read the DTC.
(6) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is DTC P1603 set?

YES : Go to Step 2.
NO : The inspection is complete.

AC305412

AB

MB991910

DATA LINK

CONNECTOR

MB991824

MB991827