Mitsubishi Galant 9G. Manual — part 880

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <2.4L ENGINE>

13A-962

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

− How

to Cope with Intermittent Malfunctions

P.00-14

).

AK303804AB

MB991910

DATA LINK
CONNECTOR

MB991824

MB991827

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <2.4L ENGINE>

13A-963

CAUTION

When the ignition key is maintained within the
range "A" (i.e., the ignition switch IG2 is in OFF
position but the cranking does not start) for more
than 1 second, PCM stores DTC U1110 (the past
trouble).
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.00-14

.

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-6

).

.

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

• CAN line harness damage or connector damage.

• A/C-ECU 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

AK204418 AB

ACC POSITION

LOCK (OFF)
POSITION

ON POSITION

START
POSITION

RANGE
"A"

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <2.4L ENGINE>

13A-964

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.

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 A/C-DTC.
(4) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the A/C-DTC set?

YES : Refer to GROUP 55B, Auto A/C Diagnosis

−

Diagnostic Trouble Code Chart

P.55B-8

.

NO : Go to Step 3.

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-965

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 012 set?

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

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 U1110 set?

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

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

− How to Cope with Intermittent

Malfunctions

P.00-14

.

AK303804AB

MB991910

DATA LINK
CONNECTOR

MB991824

MB991827

AK303804AB

MB991910

DATA LINK
CONNECTOR

MB991824

MB991827