Mitsubishi Galant (2004+). Manual - part 1029

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <2.4L ENGINE>

13A-933

COMMENT

Current Trouble

• Some of the possible causes are a harness or 

connector damage between the PCM and the 
combination meter on the CAN bus line, a failure 
in the combination meter power supply system, a 
failure in the combination meter, or a failure in the 
PCM.

Past Trouble

• Proceed to troubleshoot based on a harness or 

connector damage on the CAN bus line between 
the PCM and combination meter, and a failure in 
the combination meter power supply system. 
Refer to "How to cope with past trouble" (Refer to 
GROUP 00, How to Use Troubleshooting/Inspec-
tion Service Points 

P.00-6

).

NOTE: If a malfunction occurred in the past, a failure 
cannot be discovered through the MUT 

−

 III CAN bus 

diagnosis even if there might be a problem with the 
CAN bus. In this case, refer to GROUP 00, How to 
Use Troubleshooting/Inspection Service Points-How 
to Cope with Intermittent Malfunction 

P.00-6

. Fur-

thermore, it is possible to narrow down the areas of 
the possible failures from the DTCs that are output 
by the ECUs, which are communicating on the CAN 
bus (Refer to GROUP 54C, CAN bus line Diagnos-
tics Flow 

P.54C-6

).

.

OBD-II DRIVE CYCLE PATTERN
None.

.

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

• CAN line harness damage or connector damage.

• Combination meter failed.

• 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, diagnose CAN bus 
line.

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) Diagnose CAN bus line.
(4) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the CAN bus line normal?

YES : Go to Step 2.
NO :  Repair the CAN bus line. Refer to GROUP 54C, Can 

Bus Diagnostics Table 

P.54C-14

. Then go to Step 6.

AK303804AB

MB991910

DATA LINK
CONNECTOR

MB991824

MB991827

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <2.4L ENGINE>

13A-934

STEP 2. Using scan tool MB991958, read the diagnostic 
trouble code (DTC).

(1) Connect scan tool MB991958 to the data link connector.
(2) Turn the ignition switch to the "ON" position.

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

YES : Refer to GROUP 54A, Chassis Electrical-Diagnostic 

Trouble Code Chart 

P.54A-13

.

NO :  Go to Step 3.

STEP 3. Using scan tool MB991958, read the diagnostic 
trouble code (DTC).

(1) Connect scan tool MB991958 to the data link connector.
(2) Turn the ignition switch to the "ON" position.

(3) Read the combination ETACS-DTC.
(4) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is DTC 013 set?

YES : Go to Step 4.
NO :  Go to Step 5.

AK303804AB

MB991910

DATA LINK
CONNECTOR

MB991824

MB991827

AK303804AB

MB991910

DATA LINK
CONNECTOR

MB991824

MB991827

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <2.4L ENGINE>

13A-935

STEP 4. Using scan tool MB991958, read the diagnostic 
trouble code (DTC).

(1) Connect scan tool MB991958 to the data link connector.
(2) Turn the ignition switch to the "ON" position.
(3) After the MFI-DTC has been deleted, read the MFI-DTC 

again.

(4) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is DTC U1108 set?

YES : Replace the combination meter. Then go to Step 6.
NO :  It can be assumed that this malfunction is intermittent 

of CAN bus line between PCM and combination 
meter. Refer to GROUP 00, How to Use 
Troubleshooting/Inspection Service Points 

P.00-6

.

STEP 5. Using scan tool MB991958, read the diagnostic 
trouble code (DTC).

(1) Connect scan tool MB991958 to the data link connector.
(2) Turn the ignition switch to the "ON" position.

(3) After the MFI-DTC has been deleted, read the MFI-DTC 

again.

(4) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is DTC U1108 set?

YES : Replace the PCM. Then go to Step 6.
NO :  It can be assumed that this malfunction is intermittent 

of CAN bus line between PCM and combination 
meter. Refer to GROUP 00, How to Use 
Troubleshooting/Inspection Service Points 

P.00-6

.

AK303804AB

MB991910

DATA LINK
CONNECTOR

MB991824

MB991827

AK303804AB

MB991910

DATA LINK
CONNECTOR

MB991824

MB991827

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <2.4L ENGINE>

13A-936

STEP 6. Using scan tool MB991958, read the diagnostic 
trouble code (DTC).

(1) Connect scan tool MB991958 to the data link connector.
(2) Turn the ignition switch to the "ON" position.
(3) After the MFI-DTC has been deleted, read the MFI-DTC 

again.

(4) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is DTC U1108 set?

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

DTC U1110: A/C-ECU TIME-OUT

CAUTION

• If the PCM output the DTC U1110, make sure 

to diagnose the CAN bus line.

• Before replacing the ECU, make sure that the 

communication circuit is operating normally.

.

DTC SET CONDITIONS

Check Conditions

• Battery positive voltage is 10 volts or higher.

• Engine is not cranked, or at least 3 seconds or 

more have passed since engine was cranked.

Judgement Criteria

• Unable to receive A/C-ECU signals through the 

CAN bus line.

.

COMMENT

Current Trouble

• Some of the possible causes are a harness or 

connector damage between the PCM and the 
A/C-ECU on the CAN bus line, a failure in the 
A/C-ECU power supply system, a failure in the 
A/C-ECU, or a failure in the PCM.

Past Trouble

• Proceed to troubleshoot based on a harness or 

connector damage on the CAN bus line between 
the PCM and A/C-ECU, and a failure in the A/C 
power supply system. Refer to "How to cope with 
past trouble" (Refer to GROUP 00, How to Use 
Troubleshooting/Inspection Service Points 

P.00-6

).

AK303804AB

MB991910

DATA LINK
CONNECTOR

MB991824

MB991827