Mitsubishi L200. Manual — part 292

TROUBLESHOOTING

AUTOMATIC TRANSMISSION

23A-75

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 54C, Explanation about
the M.U.T.-III CAN Bus Diagnostics ).

PROBABLE CAUSES

• Damaged wiring harness or connector

• Malfunction of the engine-ECU

• Malfunction of the A/T-ECU

DIAGNOSIS PROCEDURE

STEP 1. M.U.T.-III CAN bus diagnostics
Using M.U.T.-III, perform CAN busline diagnosis.

Q: Is the check result normal?

YES :

Go to Step 2.

NO :

Repair the CAN busline (Refer to
GROUP54C, Diagnosis

− Can Bus

Diagnostic Chart ), and then go to Step 4.

STEP 2. M.U.T.-III other system diagnosis codes
Check whether the diesel fuel system diagnosis
codes are set or not.

Q: Is the diagnosis code output?

YES :

Diagnose the diesel fuel system (Refer to

GROUP 13A, Troubleshooting ).

NO :

Go to Step 3.

STEP 3. M.U.T.-III diagnosis code
Reconfirm whether the diagnosis codes are output
from A/T-ECU.
(1) Erase the diagnosis code.
(2) Turn the ignition switch to ON position.
(3) Check if the diagnosis code is set.

Q: Is the diagnosis code output?

YES :

Go to Step 4.

NO :

Intermittent malfunction in CAN busline
between engine-ECU and A/T-ECU (Refer
to GROUP 00

− How to Use

Troubleshooting/Inspection Service Points

−

How to Cope with Intermittent Malfunction ).

STEP 4. Replace the engine-ECU
After replacing the engine-ECU, re-check the A/T
diagnosis code output.

Q: Is the diagnosis code output?

YES :

Replace the A/T-ECU.

NO :

The check is end.

Code No.U1073: Bus off

CAUTION

• If diagnosis code U1073 is set in the A/T-ECU,

always diagnose the CAN main bus line. If
there is any fault in the CAN bus lines, an
incorrect diagnosis code may be set.

• Whenever the ECU is replaced, ensure that

the communication circuit is normal.

DIAGNOSIS CODE SET CONDITIONS
The failure is possibly caused by malfunction of the
harness and connector in CAN busline or by mal-
function in A/T-ECU.

PROBABLE CAUSES

• Damaged wiring harness or connector

• Malfunction of the A/T-ECU

DIAGNOSIS PROCEDURE

STEP 1. M.U.T.-III CAN bus diagnostics
Using M.U.T.-III, perform CAN busline diagnosis.

Q: Is the check result normal?

YES :

Go to Step 2.

NO :

Repair the CAN bus line (Refer to GROUP
54C, CAN bus line Diagnostic flow .) Then
go to Step 3.

STEP 2. M.U.T.-III diagnosis code
Check again if the diagnosis code is set.
(1) Turn the ignition switch to the ON position.
(2) Erase the diagnosis code.
(3) Turn the ignition switch to the LOCK (OFF)

position.

(4) Turn the ignition switch to the ON position.
(5) Check if the diagnosis code is set.
(6) Turn the ignition switch to the LOCK (OFF)

position.

Q: Is code No.U1073 set?

YES :

Replace the A/T-ECU. Then go to Step 3.

NO :

Intermittent malfunction (Refer to GROUP
00

− How to Use Troubleshooting/

Inspection Service Points ).

TROUBLESHOOTING

AUTOMATIC TRANSMISSION

23A-76

STEP 3. Check whether the diagnosis code is
reset.
Check again if the diagnosis code is set.
(1) Turn the ignition switch to the ON position.
(2) Erase the diagnosis code.
(3) Turn the ignition switch to the LOCK (OFF)

position.

(4) Turn the ignition switch to the ON position.
(5) Check if the diagnosis code is set.
(6) Turn the ignition switch to the LOCK (OFF)

position.

Q: Is code No.U1073 set?

YES :

Go to Step 1.

NO :

The procedure is complete.

Code No.U1100: Engine-ECU time-out (related to engine)

CAUTION

• If diagnosis code U1100 is set in the A/T-ECU,

always diagnose the CAN main bus line. If
there is any fault in the CAN bus lines, an
incorrect diagnosis code may be set.

• Whenever the ECU is replaced, ensure that

the communication circuit is normal.

DIAGNOSIS CODE SET CONDITIONS

Current trouble

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

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

Past trouble

• Carry out diagnosis with particular emphasis on

connector(s) or wiring harness in the CAN bus
lines between the engine-ECU and the A/T-ECU,
and the power supply system to the engine-ECU.
For diagnosis procedures, refer to "How to cope
with past trouble" (Refer to GROUP 00, How to
Use Troubleshooting/Inspection Service Points ).

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

M.U.T.-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/Inspec-
tion Service Points

−

How to Cope with Intermit-

tent Malfunctions ). 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 54C, Explanation about
the M.U.T.-III CAN Bus Diagnostics ).

PROBABLE CAUSES

• Damaged wiring harness or connector

• Malfunction of the engine-ECU

• Malfunction of the A/T-ECU

DIAGNOSIS PROCEDURE

STEP 1. M.U.T.-III CAN bus diagnostics
Using M.U.T.-III, perform CAN busline diagnosis.

Q: Is the check result normal?

YES :

Go to Step 2 .

NO :

Repair the CAN busline (Refer to
GROUP54C, Diagnosis

− Can Bus

Diagnostic Chart ), and then go to Step 6.

STEP 2. M.U.T.-III other system diagnosis codes
Check whether the diesel fuel system diagnosis
codes are set or not.

Q: Is the diagnosis code set?

YES :

Diagnose the diesel fuel system (Refer to

GROUP 13A, Troubleshooting ).

NO :

Go to Step 3.

STEP 3. M.U.T.-III other system diagnosis codes
Check if a diagnosis code, which relates to CAN
communication-linked systems below, is set.

• ETACS-ECU: Code No.U1100

Q: Is the diagnosis code set?

YES :

Go to Step 4.

NO :

Go to Step 5.

STEP 4. M.U.T.-III diagnosis code
Reconfirm whether the diagnosis codes are output
from A/T-ECU.
(1) Erase the diagnosis code.
(2) Turn the ignition switch to ON position.
(3) Check if the diagnosis code is set.

Q: Is the diagnosis code output?

YES :

Replace engine-ECU. Then go to Step 6.

NO :

Intermittent malfunction in CAN busline
between engine-ECU and A/T-ECU (Refer
to GROUP 00

− How to Use

Troubleshooting/Inspection Service Points ).

TROUBLESHOOTING

AUTOMATIC TRANSMISSION

23A-77

STEP 5. M.U.T.-III diagnosis code
Reconfirm whether the diagnosis codes are output
from A/T-ECU.
(1) Erase the diagnosis codes being output.
(2) Ignition switch: LOCK (OFF) to ON
(3) Confirm whether the diagnosis codes are output.

Q: Is the diagnosis code output?

YES :

Replace A/T-ECU. Then go to Step 6.

NO :

Intermittent malfunction in CAN busline
between engine-ECU and A/T-ECU (Refer
to GROUP 00

− How to Use

Troubleshooting/Inspection Service Points ).

STEP 6. M.U.T.-III diagnosis code
Reconfirm whether the diagnosis codes are output
from A/T-ECU.
(1) Erase the diagnosis codes being output.
(2) Ignition switch: LOCK (OFF) to ON
(3) Confirm whether the diagnosis codes are output.

Q: Is the diagnosis code output?

YES :

Go to step 1.

NO :

The procedure is complete.

Code No. U1102 ASTC-ECU time-out

CAUTION

• If diagnosis code U1102 is set in the A/T-ECU,

always diagnose the CAN main bus line. If
there is any fault in the CAN bus lines, an
incorrect diagnosis code may be set.

• Whenever the ECU is replaced, ensure that

the communication circuit is normal.

DIAGNOSIS CODE SET CONDITIONS

Current trouble

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

lines between the ASTC-ECU and the A/T-ECU,
the power supply system to the ASTC-ECU, the
ASTC-ECU itself, or the A/T-ECU may be defec-
tive.

Past trouble

• Carry out diagnosis with particular emphasis on

connector(s) or wiring harness in the CAN bus
lines between the ASTC-ECU and the A/T-ECU,
and the power supply system to the ASTC-ECU.
For diagnosis procedures, refer to "How to cope
with past trouble" (Refer to GROUP 00, How to
Use Troubleshooting/Inspection Service Points ).

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

M.U.T.-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/Inspec-
tion Service Points

−

How to Cope with Intermit-

tent Malfunctions ). 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 54C, Explanation about
the M.U.T.-III CAN Bus Diagnostics ).

PROBABLE CAUSES

• Damaged wiring harness or connector

• Malfunction of the ASTC-ECU

• Malfunction of the A/T-ECU

DIAGNOSIS PROCEDURE

STEP 1. M.U.T.-III CAN bus diagnostics
Using M.U.T.-III, perform CAN busline diagnosis.

Q: Is the check result normal?

YES :

Go to Step 2.

NO :

Repair the CAN busline (Refer to
GROUP54C, Diagnosis

− Can Bus

Diagnostic Chart ), and then go to Step 4.

STEP 2. M.U.T.-III other system diagnosis codes
Check whether the ASTC system diagnosis codes
are set or not.

Q: Is the diagnosis code output?

YES :

Diagnose the ASTC system (Refer to

GROUP 35C, Troubleshooting ).

NO :

Go to Step 3.

STEP 3. M.U.T.-III diagnosis code
Reconfirm whether the diagnosis codes are output
from A/T-ECU.
(1) Erase the diagnosis code.
(2) Turn the ignition switch to ON position.
(3) Check if the diagnosis code is set.

Q: Is the diagnosis code output?

TROUBLESHOOTING

AUTOMATIC TRANSMISSION

23A-78

YES :

Go to Step 4.

NO :

Intermittent malfunction in CAN busline
between ASTC-ECU and A/T-ECU (Refer to
GROUP 00

− How to Use Troubleshooting/

Inspection Service Points

− How to Cope

with Intermittent Malfunction ).

STEP 4. Replace the ASTC-ECU
After replacing the ASTC-ECU, re-check the A/T
diagnosis code output.

Q: Is the diagnosis code output?

YES :

Replace the A/T-ECU.

NO :

The check is end.

Code No.U1109: ETACS-ECU time-out

CAUTION

• If diagnosis code U1109 is set in the A/T-ECU,

always diagnose the CAN main bus line. If
there is any fault in the CAN bus lines, an
incorrect diagnosis code may be set.

• Whenever the ECU is replaced, ensure that

the communication circuit is normal.

DIAGNOSIS CODE SET CONDITIONS

Current trouble

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

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

Past trouble

• Carry out diagnosis with particular emphasis on

connector(s) or wiring harness in the CAN bus
lines between the ETACS-ECU and the A/T-ECU,
and the power supply system to the ETACS-ECU.
For diagnosis procedures, refer to "How to cope
with past trouble" (Refer to GROUP 00, How to
Use Troubleshooting/Inspection Service Points ).

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

M.U.T.-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/Inspec-
tion Service Points

−

How to Cope with Intermit-

tent Malfunctions ). 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 54C, Explanation about
the M.U.T.-III CAN Bus Diagnostics ).

PROBABLE CAUSES

• Damaged wiring harness or connector

• Malfunction of the ETACS-ECU

• Malfunction of the A/T-ECU

DIAGNOSIS PROCEDURE

STEP 1. M.U.T.-III CAN bus diagnostics
Using M.U.T.-III, perform CAN busline diagnosis.

Q: Is the check result normal?

YES :

Go to Step 2 .

NO :

Repair the CAN busline (Refer to
GROUP54C, Diagnosis

− Can Bus

Diagnostic Chart ), and then go to Step 6.

STEP 2. M.U.T.-III other system diagnosis codes
Check whether the local interconnect network sys-
tem diagnosis codes are set or not.

Q: Is the diagnosis code set?

YES :

Diagnose the ETACS system (Refer to

GROUP 54A, Troubleshooting ).

NO :

Go to Step 3.

STEP 3. M.U.T.-III other system diagnosis codes
Check if a diagnosis code, which relates to CAN
communication-linked systems below, is set.

• Engine-ECU: Code No.U1109

Q: Is the diagnosis code set?

YES :

Go to Step 4.

NO :

Go to Step 5.

STEP 4. M.U.T.-III diagnosis code
Reconfirm whether the diagnosis codes are output
from A/T-ECU.
(1) Erase the diagnosis code.
(2) Turn the ignition switch to ON position.
(3) Check if the diagnosis code is set.

Q: Is the diagnosis code output?

YES :

Replace ETACS-ECU. Then go to Step 6.

NO :

Intermittent malfunction in CAN busline
between ETACS-ECU and A/T-ECU (Refer
to GROUP 00

− How to Use

Troubleshooting/Inspection Service Points ).