Mitsubishi Outlander GS45X. Manual - part 720

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <2.4L ENGINE>

13A-703

STEP 3. Using scan tool MB991958, read the diagnostic 
trouble code (DTC).
(1) Turn the ignition switch to the "ON" position.
(2) Check that the other ECU performing CAN communication 

with TCM sets DTC No. U0101. Refer to GROUP 54C, CAN 
Communication-related DTC (U-code) Table 

P.54C-220

.

(3) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is DTC U0101 set?

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

STEP 4. Using scan tool MB991958, read the diagnostic 
trouble code (DTC).
(1) Turn the ignition switch to the "ON" position.
(2) After the MFI-DTC has been deleted, read the MFI-DTC 

again.

(3) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is DTC U0101 set?

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

of CAN bus line between ECM and TCM. Refer to 
GROUP 00, How to Use Troubleshooting/Inspection 
Service Points 

− How to Cope with Intermittent 

Malfunctions 

P.00-15

.

STEP 5. Using scan tool MB991958, read the diagnostic 
trouble code (DTC).
(1) Turn the ignition switch to the "ON" position.
(2) After the MFI-DTC has been deleted, read the MFI-DTC 

again.

(3) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is DTC U0101 set?

YES : Replace the ECM. When the ECM is replaced, 

register the ID code. Refer to GROUP 42B, Diagnosis 
− ID Code Registration Judgment Table <Vehicles 

with KOS> 

P.42B-15

 or GROUP 42C, Diagnosis 

− ID 

Codes Registration Judgment Table <Vehicles with 
WCM> 

P.42C-10

. Then go to Step 6.

NO :  It can be assumed that this malfunction is intermittent 

of CAN bus line between ECM and TCM. Refer to 
GROUP 00, How to Use Troubleshooting/Inspection 
Service Points 

− How to Cope with Intermittent 

Malfunctions 

P.00-15

.

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <2.4L ENGINE>

13A-704

STEP 6. Using scan tool MB991958, read the diagnostic 
trouble code (DTC).
(1) Turn the ignition switch to the "ON" position.
(2) After the MFI-DTC has been deleted, read the MFI-DTC 

again.

(3) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is DTC U0101 set?

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

DTC U0121: ASC-ECU Time-out

CAUTION

• If the ECM output the DTC U0121, 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.

• At least 2 seconds have passed since the ignition 

switch is turned to "ON" position.

Judgement Criterion

• Unable to receive ASC-ECU signals through the 

CAN bus line for 4 seconds.

.

COMMENT

Current Trouble

• Some of the possible causes are a harness or 

connector damage between the ECM and the 
ASC-ECU on the CAN bus line, a failure in the 
ASC-ECU power supply system, a failure in the 
ASC-ECU, or a failure in the ECM.

Past Trouble

• Proceed to troubleshoot based on a harness or 

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

− How 

to Treat Past Trouble 

P.00-17

).

NOTE: If a malfunction occurred in the past, a failure 
cannot be discovered through the MB991958 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 Malfunctions 

P.00-15

. 

Furthermore, 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-10

).

.

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

• CAN line harness damage or connector damage.

• ASC-ECU failed.

• ECM failed. 

DIAGNOSIS

Required Special Tools:

• MB991958: Scan tool (M.U.T.-III Sub Assembly)

• MB991824: V.C.I.

• MB991827: USB Cable

• MB991910: Main Harness A

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <2.4L ENGINE>

13A-705

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, 

Diagnosis 

− Can Bus Diagnostics Table 

P.54C-17

. 

Then go to Step 6.

STEP 2. Using scan tool MB991958, read the diagnostic 
trouble code (DTC).
(1) Turn the ignition switch to the "ON" position.
(2) Read the ASC-DTC.
(3) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the ASC-DTC set?

YES : Refer to GROUP 35C, Diagnosis 

− Diagnostic 

Trouble Code Chart 

P.35C-18

.

NO :  Go to Step 3.

STEP 3. Using scan tool MB991958, read the diagnostic 
trouble code (DTC).
(1) Turn the ignition switch to the "ON" position.
(2) Check that the other ECU performing CAN communication 

with ASC-ECU sets DTC No. U0121. Refer to GROUP 54C, 
CAN Communication-related DTC (U-code) Table 

P.54C-220

.

(3) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is DTC U0121 set?

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

AK700568AB

MB991824

MB991827

MB991910

Data link
connector

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <2.4L ENGINE>

13A-706

STEP 4. Using scan tool MB991958, read the diagnostic 
trouble code (DTC).
(1) Turn the ignition switch to the "ON" position.
(2) After the MFI-DTC has been deleted, read the MFI-DTC 

again.

(3) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is DTC U0121 set?

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

of CAN bus line between ECM and ASC-ECU. Refer 
to GROUP 00, How to Use 
Troubleshooting/Inspection Service Points 

− How to 

Cope with Intermittent Malfunctions 

P.00-15

.

STEP 5. Using scan tool MB991958, read the diagnostic 
trouble code (DTC).
(1) Turn the ignition switch to the "ON" position.
(2) After the MFI-DTC has been deleted, read the MFI-DTC 

again.

(3) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is DTC U0121 set?

YES : Replace he ECM. When the ECM is replaced, register 

the ID code. Refer to GROUP 42B, Diagnosis 

− ID 

Code Registration Judgment Table <Vehicles with 
KOS> 

P.42B-15

 or GROUP 42C, Diagnosis 

− ID 

Codes Registration Judgment Table <Vehicles with 
WCM> 

P.42C-10

. Then go to Step 6.

NO :  It can be assumed that this malfunction is intermittent 

of CAN bus line between ECM and ASC-ECU. Refer 
to GROUP 00, How to Use 
Troubleshooting/Inspection Service Points 

− How to 

Cope with Intermittent Malfunctions 

P.00-15

.

STEP 6. Using scan tool MB991958, read the diagnostic 
trouble code (DTC).
(1) Turn the ignition switch to the "ON" position.
(2) After the MFI-DTC has been deleted, read the MFI-DTC 

again.

(3) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is DTC U0121 set?

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