Mitsubishi Grandis. Manual - part 144

DIAGNOSTIC TROUBLE CODE PROCEDURES

SMART WIRING SYSTEM (SWS) USING SWS MONITOR

54C-38

<A/T> or the engine-ECU <M/T>. For diagnosis 
procedures, refer to "How to treat past trouble" 
(Refer to GROUP 00 

− How to Use 

Troubleshooting/Inspection Service Points 

P.00-5

).

NOTE: For a past trouble, you can not find it by the 

MUT-III CAN bus diagnostics even if there is any 
failure in CAN bus lines. In this case, refer to 
GROUP 00, How to Use 
Troubleshooting/Inspection Service Points 

P.00-5

 

and check the CAN bus lines. You can narrow 
down the possible cause of the trouble by 
referring to the diagnosis code, which is set 
regarding the CAN communication-linked ECUs 
(Refer to GROUP 54D 

−

 CAN Bus Line 

Diagnostic Flow 

P.54D-9

).

POSSIBLE CAUSES

• Malfunction of the engine-A/T-ECU <A/T> or 

engine-ECU <M/T>

• Malfunction of the ETACS-ECU

• Malfunction of the CAN bus

DIAGNOSTIC PROCEDURE

Step 1. MUT-III CAN bus diagnostics
Use the MUT-III to diagnose the CAN bus lines.

Q: Is the check result normal?

YES : 

Go to Step 2.

NO : 

Repair the CAN bus line (Refer to GROUP 
54D 

− Diagnosis 

P.54D-16

). Repair the 

CAN bus line and go to Step 6.

Step 2. Check for engine control diagnosis code.

Check whether the engine control-related diagnosis 
code is set.

Q: Is the check result normal?

YES : 

Go to Step 3.

NO : 

Engine (Refer to GROUP 13A 

− 

Troubleshooting 

P.13A-11

).

Step 3. MUT-III diagnosis code

Check if a diagnosis code, which relates to CAN 
communication-linked systems below, is set.

• Combination meter

U1100: Engine-related time-out diagnosis code

• Multi-display

U1100: Engine-related time-out diagnosis code

Q: Is the check result normal?

YES : 

Go to Step 5.

NO : 

Go to Step 4.

Step 4. Check whether the diagnosis code is 
reset.

Check again if the diagnosis code is set.
(1) Erase the diagnosis code.
(2) Ignition switch: LOCK (OFF) position to ON
(3) On completion, check that the diagnosis code is 

not reset.

Q: Is the check result normal?

YES : 

A poor connection, open circuit or other 

intermittent malfunction is present in the 
CAN bus lines between the engine-A/T-ECU 
<A/T> or the engine-ECU <M/T> and the 
ETACS-ECU (Refer to GROUP 00 

− How to 

Use Troubleshooting/Inspection Service 
Points 

P.00-5

).

NO : 

Replace the engine-A/T-ECU, and then go 
to Step 6.

Step 5. Check whether the diagnosis code is 
reset.

Check again if the diagnosis code is set.
(1) Erase the diagnosis code.
(2) Ignition switch: LOCK (OFF) position to ON
(3) On completion, check that the diagnosis code is 

not reset.

Q: Is the check result normal?

YES : 

A poor connection, open circuit or other 

intermittent malfunction is present in the 
CAN bus lines between the engine-A/T-ECU 
<A/T> or the engine-ECU <M/T> and the 
ETACS-ECU (Refer to GROUP 00 

− How to 

Use Troubleshooting/Inspection Service 
Points 

P.00-5

).

NO : 

Replace the ETACS-ECU, and then go to 
Step 6.

Step 6. Check whether the diagnosis code is 
reset.

Recheck if the diagnosis code is set.
(1) Erase the diagnosis code.
(2) Ignition switch: LOCK (OFF) position to ON
(3) On completion, check that the diagnosis code is 

not reset.

Q: Is the check result normal?

YES : 

The procedure is complete.

NO : 

Return to Step 1.

DIAGNOSTIC TROUBLE CODE PROCEDURES

SMART WIRING SYSTEM (SWS) USING SWS MONITOR

54C-39

Diagnosis code No.12 Engine-A/T-ECU time-out (related to A/T)

CAUTION

If diagnosis code No.12 is set in the ETACS, 
diagnose the CAN main bus line.

CAUTION

Whenever the ECU is replaced, ensure that the 
communication circuit is normal.

TROUBLE JUDGMENT

• The ETACS-ECU receives engine and 

transmission control-related signals from the 
engine-A/T-ECU via the CAN bus lines. If the 
ECU cannot receive the transmission control 
signal at all, diagnosis code No.12 will be set.

NOTE: For M/T-vehicles, diagnosis code No.12 does 
not mean that there is a problem.

COMMENTS ON TROUBLE SYMPTOM

Current trouble

• Connector(s) or wiring harness in the CAN bus 

lines between the ETACS-ECU and the 
engine-A/T-ECU, the power supply system to the 
engine-A/T-ECU, or the ETACS-ECU itself may 
be defective.

Past trouble

• If diagnosis code No.12 is stored as a past 

trouble, carry out diagnosis with particular 
emphasis on wiring and connector(s) in the CAN 
bus line between the ETACS-ECU and the 
engine-A/T-ECU, and the power supply system to 
the engine-A/T-ECU. For diagnosis procedures, 
refer to "How to treat past trouble" (Refer to 
GROUP 00 

− How to Use 

Troubleshooting/Inspection Service Points 

P.00-5

).

NOTE: For a past trouble, you can not find it by the 

MUT-III CAN bus diagnostics even if there is any 
failure in CAN bus lines. In this case, refer to 
GROUP 00, How to Use 
Troubleshooting/Inspection Service Points 

P.00-5

 

and check the CAN bus lines. You can narrow 
down the possible cause of the trouble by 
referring to the diagnosis code, which is set 
regarding the CAN communication-linked ECUs 
(Refer to GROUP 54D 

−

 CAN Bus Line 

Diagnostic Flow 

P.54D-9

).

POSSIBLE CAUSES

• Malfunction of the engine-A/T-ECU

• Malfunction of the ETACS-ECU

• Malfunction of the CAN bus

DIAGNOSTIC PROCEDURE

Step 1. MUT-III CAN bus diagnostics
Use the MUT-III to diagnose the CAN bus lines.

Q: Is the check result normal?

YES : 

Go to Step 2.

NO : 

Repair the CAN bus line (Refer to GROUP 
54D 

− Diagnosis 

P.54D-16

). On completion, 

go to Step 6.

Step 2. Check for A/T control-related diagnosis 
code.
Check if an A/T system diagnosis code is set.

Q: Is the check result normal?

YES : 

Go to Step 3.

NO : 

Diagnose the automatic transmission 
system (Refer to GROUP 23 

− 

Troubleshooting 

P.23A-17

).

Step 3. MUT-III diagnosis code
Check if a diagnosis code, which relates to CAN 
communication-linked systems below, is set.

• Combination meter

U1101: Engine-related time-out diagnosis code

Q: Is the check result normal?

YES : 

Go to Step 5.

NO : 

Go to Step 4.

Step 4. Check whether the diagnosis code is 
reset.
Check again if the diagnosis code is set.
(1) Erase the diagnosis code.
(2) Ignition switch: LOCK (OFF) position to ON
(3) On completion, check that the diagnosis code is 

not reset.

Q: Is the check result normal?

YES : 

A poor connection, open circuit or other 

intermittent malfunction is present in the 
CAN bus lines between the engine-A/T-ECU 
and the ETACS-ECU (Refer to GROUP 00 

− 

How to Use Troubleshooting/Inspection 
Service Points 

P.00-5

).

NO : 

Replace the engine-A/T-ECU, and then go 
to Step 6.

DIAGNOSTIC TROUBLE CODE PROCEDURES

SMART WIRING SYSTEM (SWS) USING SWS MONITOR

54C-40

Step 5. Check whether the diagnosis code is 
reset.
Check again if the diagnosis code is set.
(1) Erase the diagnosis code.
(2) Ignition switch: LOCK (OFF) position to ON
(3) On completion, check that the diagnosis code is 

not reset.

Q: Is the check result normal?

YES : 

A poor connection, open circuit or other 

intermittent malfunction is present in the 
CAN bus lines between the engine-A/T-ECU 
and the ETACS-ECU (Refer to GROUP 00 

− 

How to Use Troubleshooting/Inspection 
Service Points 

P.00-5

).

NO : 

Replace the ETACS-ECU, and then go to 
Step 6.

Step 6. Check whether the diagnosis code is 
reset.
Recheck if the diagnosis code is set.
(1) Erase the diagnosis code.
(2) Ignition switch: LOCK (OFF) position to ON
(3) On completion, check that the diagnosis code is 

not reset.

Q: Is the check result normal?

YES : 

The procedure is complete.

NO : 

Return to Step 1.

Diagnosis code No.13 A/C-ECU time-out

CAUTION

If diagnosis code No.13 is set in the ETACS-ECU, 
diagnose the CAN bus lines.

CAUTION

Whenever the ECU is replaced, ensure that the 
input and output signal circuits are normal.

TROUBLE JUDGMENT

The ETACS-ECU receives air conditioner 
system-related signal from the A/C-ECU. If air 
conditioner control system-related signal can not be 
received at all, diagnosis code No.13 will be set.

COMMENT ON TROUBLE SYMPTOM

Current trouble

• Connector(s) or wiring harness in the CAN bus 

lines between the A/C-ECU and the 
ETACS-ECU, the power supply system to the 
combination meter, the combination meter itself, 
or the ETACS-ECU may be defective.

Past trouble

• If diagnosis code No.13 is stored as a past 

trouble, carry out diagnosis with particular 
emphasis on wiring and connector(s) in the CAN 
bus line between the ETACS-ECU and the 
A/C-ECU, and the power supply system to the 
A/C-ECU. For diagnosis procedures, refer to 
"How to treat past trouble" (Refer to GROUP 00 

− 

How to Use Troubleshooting/Inspection Service 
Points 

P.00-5

).

NOTE: For a past trouble, you can not find it by the 

MUT-III CAN bus diagnostics even if there is any 
failure in CAN bus lines. In this case, refer to 
GROUP 00, How to Use 
Troubleshooting/Inspection Service Points 

P.00-5

 

and check the CAN bus lines. You can narrow 
down the possible cause of the trouble by 
referring to the diagnosis code, which is set 
regarding the CAN communication-linked ECUs 
(Refer to GROUP 54D 

−

 CAN Bus Line 

Diagnostic Flow 

P.54D-9

).

POSSIBLE CAUSES

• Malfunction of the A/C-ECU

• Malfunction of the ETACS-ECU

• Damaged harness wires and connectors

DIAGNOSIS PROCEDURE

Step 1. MUT-III CAN bus diagnostics

Use the MUT-III to diagnose the CAN bus lines.

Q: Is the check result normal?

YES : 

Go to Step 2.

NO : 

Repair the CAN bus line (Refer to GROUP 
54D 

− Diagnosis 

P.54D-16

). On completion, 

go to Step 5.

Step 2. MUT-III diagnosis code

Check if an A/C-ECU diagnosis code is set.

Q: Is the diagnosis code set?

DIAGNOSTIC TROUBLE CODE PROCEDURES

SMART WIRING SYSTEM (SWS) USING SWS MONITOR

54C-41

YES : 

Diagnose the A/C-ECU (Refer to GROUP 

55 

− Troubleshooting 

P.55-7

).

NO : 

Go to Step 3.

Step 3. Check whether the diagnosis code is 
reset.

Check again if the diagnosis code is set.
(1) Erase the diagnosis code.
(2) Ignition switch: ON 

→ LOCK (OFF) → ON

(3) On completion, check that the diagnosis code is 

not reset.

Q: Is the check result normal?

YES : 

A poor connection, open circuit or other 

intermittent malfunction is present in the 
CAN bus lines between the A/C-ECU and 
the ETACS-ECU (Refer to GROUP 00 

− 

How to Use Troubleshooting/Inspection 
Service Points 

P.00-5

).

NO : 

Replace the A/C-ECU, and then go to Step 
4.

Step 4. Check whether the diagnosis code is 
reset.

Check again if the diagnosis code is set.
(1) Erase the diagnosis code.

(2) Ignition switch: ON 

→ LOCK (OFF) → ON

(3) On completion, check that the diagnosis code is 

not reset.

Q: Is the check result normal?

YES : 

A poor connection, open circuit or other 

intermittent malfunction is present in the 
CAN bus lines between the A/C-ECU and 
the ETACS-ECU (Refer to GROUP 00 

− 

How to Use Troubleshooting/Inspection 
Service Points 

P.00-5

).

NO : 

Replace the ETACS-ECU, and then go to 
Step 5.

Step 5. Check whether the diagnosis code is 
reset.

Recheck if the diagnosis code is set.
(1) Erase the diagnosis code.
(2) Ignition switch: ON 

→ LOCK (OFF) → ON

(3) On completion, check that the diagnosis code is 

not reset.

Q: Is the check result normal?

YES : 

The procedure is complete.

NO : 

Return to Step 1.

Diagnosis code No.14 Meter time-out

CAUTION

If diagnosis code No.14 is set in the ETACS-ECU, 
diagnose the CAN bus lines.

CAUTION

Whenever the ECU is replaced, ensure that the 
input and output signal circuits are normal.

TROUBLE JUDGMENT

The ETACS-ECU receives combination 
meter-related signal from the combination meter. If 
meter-related signal can not be received at all, 
diagnosis code No.14 will be set.

COMMENT ON TROUBLE SYMPTOM

Current trouble

• Connector(s) or wiring harness in the CAN bus 

lines between the combination meter and the 
ETACS-ECU, the power supply system to the 
combination meter, the combination meter itself, 
or the ETACS-ECU may be defective.

Past trouble

• If diagnosis code No.14 is stored as a past 

trouble, carry out diagnosis with particular 
emphasis on wiring and connector(s) in the CAN 
bus line between the combination meter and the 
ETACS-ECU, and the power supply system to the 
combination meter. For diagnosis procedures, 
refer to "How to treat past trouble" (Refer to 
GROUP 00 

− How to Use 

Troubleshooting/Inspection Service Points 

P.00-5

).

NOTE: For a past trouble, you can not find it by the 

MUT-III CAN bus diagnostics even if there is any 
failure in CAN bus lines. In this case, refer to 
GROUP 00, How to Use 
Troubleshooting/Inspection Service Points 

P.00-5

 

and check the CAN bus lines. You can narrow 
down the possible cause of the trouble by 
referring to the diagnosis code, which is set 
regarding the CAN communication-linked ECUs 
(Refer to GROUP 54D 

−

 CAN Bus Line 

Diagnostic Flow 

P.54D-9

).