Mitsubishi Outlander XL. Manual - part 1189

Past trouble

｠

If DTC U0154 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 Occupant classification-ECU, and the
power supply system to the Occupant classification-
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 Occupant classification-ECU

｠

Malfunction of the A/C-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

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 Occupant
classification-ECU diagnostic trouble code.
Check whether an Occupant classification-ECU DTCs are set or
not.

AIR CONDITIONING

55A-47

MANUAL A/C DIAGNOSIS

(1)

Turn the ignition switch to the "ON" position.

(2)

Check for Occupant classification-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 Occupant classification-ECU (Refer to

GROUP 52B, Diagnostic Trouble Code P.52B-33).

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.

｠

ETACS-ECU
DTC  indicating  a  time-out  error  related  to  the  Occupant
classification-ECU 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.

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 SRS-ECU and the A/C-ECU (Refer to GROUP 00E, Harness
Connector Inspection P.00E-2.)

NO:

 Replace the Occupant classification-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 SRS-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.

55A-48

AIR CONDITIONING

MANUAL A/C DIAGNOSIS

DTC U0155: Combination meter Time-out

M15502000952USA0000010000

If DTC U0155 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  the  air  conditioning  control-
related  signals  from  the  combination  meter  via  the
CAN bus lines. If any of the air conditioning control-
related signals from the combination meter cannot be
received, the diagnostic trouble code U0155 is stored.

TECHNICAL DESCRIPTION (COMMENT)

Current trouble

｠

Connector(s) or wiring harness in the CAN bus lines
between the combination meter and the A/C-ECU,
the power supply system to the combination meter,
the combination meter itself, or the A/C-ECU may
be defective.

Past trouble

｠

If DTC U0155 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  combination  meter,  and  the  power
supply  system  to  the  combination  meter.  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 combination meter

｠

Malfunction of the A/C-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

AIR CONDITIONING

55A-49

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. Using scan tool MB991958 read the combination
meter diagnostic trouble code.
Check whether a combination meter DTCs are set or not.

(1)

Turn the ignition switch to the "ON" position.

(2)

Check for combination meter 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 combination meter (Refer to GROUP 54Ab,

Diagnostic Trouble Code P.52B-33).

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.

｠

ETACS-ECU
DTC  indicating  a  time-out  error  related  to  the  combination
meter 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.

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.

55A-50

AIR CONDITIONING

MANUAL A/C DIAGNOSIS