Mitsubishi Outlander GS45X. Manual — part 1004

MANUAL A/C DIAGNOSIS

TSB Revision

HEATER, AIR CONDITIONING AND VENTILATION

55A-43

STEP 3. Using scan tool MB991958, check for any
diagnostic trouble code.
Check if a DTC, which relates to CAN communication-linked
systems below, is set.

• WCM <vehicles with WCM>

B2204: Coding data unmatched

• KOS <vehicles with KOS>

B2204: Coding data unmatched

(1) Turn the ignition switch to the "ON" position.
(2) Check for a DTC related to the relevant system.
(3) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the check result satisfactory?

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

STEP 4. Recheck for diagnostic trouble code.
Check again if the DTC is set.
(1) Turn the ignition switch to the "ON" position.
(2) Check if the DTC is set.
(3) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the check result satisfactory?

YES : A poor connection, open circuit or other intermittent

malfunction is present in the lines between the
ETACS-ECU and the A/C-ECU (Refer to GROUP
00E, Harness Connector Inspection

P.00E-2

.)

NO : Replace the ETACS-ECU. On completion, check that

the DTC is not reset.

STEP 5. Recheck for diagnostic trouble code.
Check again if the DTC is set.
(1) Turn the ignition switch to the "ON" position.
(2) Check if the DTC is set.
(3) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the check result satisfactory?

YES : A poor connection, open circuit or other intermittent

malfunction is present in the lines between the
ETACS-ECU and the A/C-ECU (Refer to GROUP
00E, Harness Connector Inspection

P.00E-2

.)

NO : Replace the A/C-ECU. On completion, check that the

DTC is not reset.

MANUAL A/C DIAGNOSIS

TSB Revision

HEATER, AIR CONDITIONING AND VENTILATION

55A-44

DTC U0019: Bus Off (CAN1)

CAUTION

If DTC U0019is set in the A/C-ECU, diagnose the
CAN main bus line.

CAUTION

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

.

TROUBLE JUDGMENT

DTC U0019 will be stored when the A/C-ECU ceases
CAN communication (bus off) and then resumes the
communication when the ignition switch is turned to
the "LOCK" (OFF) position.

.

TECHNICAL DESCRIPTION (COMMENT)

The wiring harness wire or connectors may have
loose, corroded, or damage terminals, or terminals
pushed back in the connector, or the A/C-ECU may
be defective.

.

TROUBLESHOOTING HINTS

• Defective connector(s) or wiring harness

• Malfunction of the A/C-ECU

DIAGNOSIS

Required Special Tools:

• MB991223: Harness Set

• MB992006: Extra Fine Probe

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

• MB991824: V.C.I.

• MB991827: M.U.T.-III USB Cable

• MB991910: M.U.T.-III Main Harness A

STEP 1. Using scan tool MB991958, diagnose the 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. Refer to "How to connect the

Scan Tool (M.U.T.-III)

P.55A-7

."

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

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

Diagnosis

P.54C-17

).

ZC501967

AC404789

AC701411AB

MB991824

MB991827

MB991910

Data link
connector

MANUAL A/C DIAGNOSIS

TSB Revision

HEATER, AIR CONDITIONING AND VENTILATION

55A-45

STEP 2. Recheck for diagnostic trouble code.
Check again if the DTC is set.
(1) Connect scan tool MB991958 to the data link connector
(2) Turn the ignition switch to the "ON" position.
(3) Check if the DTC is set.
(4) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the check result satisfactory?

YES : There is an intermittent malfunction such as poor

engaged connector(s) or open circuit (Refer to
GROUP 00, How to Use Troubleshooting/Inspection
Service Points

− How to Cope with Intermittent

Malfunctions

P.00-15

.)

NO : Replace the A/C-ECU. On completion, check that the

DTC is not reset.

DTC U0141: ETACS-ECU Time-out

CAUTION

If DTC U0141 is set in the A/C-ECU, diagnose the
CAN main bus line.

CAUTION

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

.

TROUBLE JUDGMENT

The A/C-ECU receives air conditioning opera-
tion-related signals from the ETACS-ECU via the
CAN bus lines. If the ECU cannot receive any of the
air conditioning control-related signals from the
ETACS-ECU, the diagnostic trouble code U0141 is
stored.

.

TECHNICAL DESCRIPTION (COMMENT)

Current trouble

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

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

Past trouble

• If DTC U0141 is stored as a past trouble, carry

out diagnosis with particular emphasis on wiring
and connector(s) in the CAN bus line between
the A/C-ECU and the ETACS-ECU, and the
power supply system to the ETACS-ECU. If the
connectors and wiring are normal, and obviously
the ECU is the cause of the trouble, replace the
ECU. If in doubt, do not replace the ECU.
NOTE: For a past trouble, you cannot find it by
the scan tool CAN bus diagnostics even if there is
a 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

P.00-15

) and check the CAN

bus lines. You can narrow down the possible
cause of the trouble by referring to the DTC,
which is set regarding the CAN communica-
tion-linked ECUs (Refer to GROUP 54C, Expla-
nation about the scan too CAN bus diagnostics

P.54C-16

).

.

TROUBLESHOOTING HINTS

• Malfunction of the A/C-ECU

• Malfunction of the ETACS-ECU

• Damaged harness wires and connectors

DIAGNOSIS

Required Special Tools:

• MB991223: Harness Set

• MB992006: Extra Fine Probe

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

• MB991824: V.C.I.

MANUAL A/C DIAGNOSIS

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HEATER, AIR CONDITIONING AND VENTILATION

55A-46

• MB991827: M.U.T.-III USB Cable

• MB991910: M.U.T.-III Main Harness A

STEP 1. Using scan tool MB991958, diagnose the 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. Refer to "How to connect the

Scan Tool (M.U.T.-III)

P.55A-7

."

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

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

Diagnosis

P.54C-17

).

STEP 2. Using scan tool MB991958 read the ETACS-ECU
diagnostic trouble code.
Check whether an ETACS-ECU DTCs are set or not.
(1) Turn the ignition switch to the "ON" position.
(2) Check for ETACS-ECU DTCs.
(3) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the check result satisfactory?

YES : Go to Step 3.
NO : Diagnose the ETACS-ECU (Refer to GROUP 54A,

Diagnostic Trouble Code

P.54A-733

).

STEP 3. Using scan tool MB991958, check for any
diagnostic trouble code.
Check if a DTC, which relates to CAN communication-linked
systems below, is set.

• Combination meter

DTC indicating a time-out error related to the engine or
automatic transaxle control system

(1) Turn the ignition switch to the "ON" position.
(2) Check for a DTC related to the relevant system.
(3) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the check result satisfactory?

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

ZC501967

AC404789

AC701411AB

MB991824

MB991827

MB991910

Data link
connector