Mitsubishi 380. Manual - part 586

MULTIPORT FUEL INJECTION (MPI) DIAG

MULTIPORT FUEL INJECTION (MPI)

13A-436

STEP 7. Using diagnostic tool , read the diagnostic trouble 
code (DTC).

CAUTION

To prevent damage to diagnostic tool , always turn the 
ignition switch to the "LOCK"(OFF) position before con-
necting or disconnecting diagnostic tool .
(1) Connect diagnostic tool 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 P0638 set?

YES : Then go to Step 8.
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

.

STEP 8. Using diagnostic tool , read the diagnostic trouble 
code (DTC).
(1) Connect diagnostic tool 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 P0638 set?

YES : Retry the troubleshooting.
NO :  The inspection is complete.

00DB076A

MB991910

DATA LINK

CONNECTOR

MB991824

MB991827

00DB076A

MB991910

DATA LINK

CONNECTOR

MB991824

MB991827

MULTIPORT FUEL INJECTION (MPI) DIAG

MULTIPORT FUEL INJECTION (MPI)

13A-437

DTC P1603: Battery Backup Line Malfunction 

.

TECHNICAL DESCRIPTION

• The ENGINE-ECU checks the open circuit of bat-

tery 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).

.

DTC SET CONDITIONS

Check Conditions

• None

Judgement Criteria

• RAM area check failed

.

EOBD DRIVE CYCLE PATTERN

None.

.

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

• Refer to component locations GROUP-

70

• Refer to configuration diagrams GROUP-

80

• Refer to circuit diagrams GROUP-

90

• Open or shorted battery backup line, harness 

damage or connector damage.

• ENGINE-ECU failed.

DIAGNOSIS

Required Special Tools:

• : Diagnostic tool (MUT-III Sub Assembly)

• MB991824: V.C.I.

• MB991827: USB Cable

• MB991910: Main Harness A

• MB992044: Power Plant ENGINE-ECU Check Harness

16DB400A

COVER

ENGINE

CONTROL

UNIT

AIR

CLEANER

MULTIPORT FUEL INJECTION (MPI) DIAG

MULTIPORT FUEL INJECTION (MPI)

13A-438

STEP 1. Using diagnostic tool , read the diagnostic trouble 
code (DTC).

CAUTION

To prevent damage to diagnostic tool , always turn the 
ignition switch to the "LOCK" (OFF) position before con-
necting or disconnecting diagnostic tool .
(1) Connect diagnostic tool 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.

00DB076A

MB991910

DATA LINK

CONNECTOR

MB991824

MB991827

MULTIPORT FUEL INJECTION (MPI) DIAG

MULTIPORT FUEL INJECTION (MPI)

13A-439

STEP 2. Measure the backup power supply voltage at 
ENGINE-ECU connector B-21 by using power plant 
ENGINE-ECU check harness special tool MB992044.
(1) Disconnect the all ENGINE-ECU connectors and connect 

power plant ENGINE-ECU check harness special tool 
MB992044 between the separated connectors.

(2) Measure the voltage between terminal No.16 and ground.

• Voltage should be battery positive voltage.

Q: Is battery positive voltage (approximately 12 volts) 

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

16DB400A

COVER

ENGINE

CONTROL

UNIT

AIR

CLEANER

03DB182A

POWER PLANT ECU 

CHECK HARNESS 

CONNECTOR