Mitsubishi Outlander XL. Manual - part 1187

STEP 1. Using scan tool MB991958, diagnose the CAN bus
line

ZC501967

AC404789

ZC5019680000

MB991824

MB991827

MB991910

Data link

connector

To prevent damage to scan tool MB991958, always turn the
ignition  switch  to  the  "LOCK"  (OFF)  position  before
connecting or disconnecting scan tool MB991958.

(1)

Connect scan tool MB991958. Refer to "How to connect the
Scan Tool (M.U.T.-III) P.55A-6."

(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 54D,

Diagnosis P.54D-17).

STEP 2. Using scan tool MB991958 read the ETACS-ECU
diagnostic trouble code.
Check whether an engine and automatic transaxle DTCs are set
or not.

(1)

Turn the ignition switch to the "ON" position.

(2)

Check for the DTC related to the ETACS-ECU.

(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 54Ab,

Diagnostic Trouble Code P.54Ad-8).

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.

AIR CONDITIONING

55A-39

MANUAL A/C DIAGNOSIS

(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.

DTC U0019: Bus Off (CAN1)

M15502000949USA0000010000

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

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

55A-40

AIR CONDITIONING

MANUAL A/C DIAGNOSIS

STEP 1. Using scan tool MB991958, diagnose the CAN bus
line

ZC501967

AC404789

ZC5019680000

MB991824

MB991827

MB991910

Data link

connector

To prevent damage to scan tool MB991958, always turn the
ignition  switch  to  the  "LOCK"  (OFF)  position  before
connecting or disconnecting scan tool MB991958.

(1)

Connect scan tool MB991958. Refer to "How to connect the
Scan Tool (M.U.T.-III) P.55A-6."

(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 54D,

Diagnosis P.54D-17).

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

M15502000948USA0000010000

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

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

TROUBLE JUDGMENT
The  A/C-ECU  receives  air  conditioning  operation-
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.

AIR CONDITIONING

55A-41

MANUAL A/C DIAGNOSIS

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/
Inspection Service Points - How to Cope with
Intermittent 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
communication-linked ECUs (Refer to GROUP 54D,
Explanation about the scan too CAN bus
diagnostics P.54D-10).

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.

｠

MB991827: M.U.T.-III USB Cable

｠

MB991910: M.U.T.-III Main Harness A

55A-42

AIR CONDITIONING

MANUAL A/C DIAGNOSIS