Mitsubishi Outlander XL. Manual - part 1184

DIAGNOSIS

Required Special Tool:

｠

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

｠

MB991824: Vehicle Communication Interface (V.C.I.)

｠

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

｠

MB991910:  M.U.T.-III  Main  Harness  A  (Vehicles  with
CAN communication system)

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.
Recheck if the DTC is set.

(1)

Erase the DTC.

(2)

Turn the ignition switch to "ON" position.

(3)

Check if the DTC is set.

Q:Is the check result satisfactory?

YES:

 It can be assumed that this malfunction is

intermittent. Refer to GROUP 00, How to Use
Troubleshooting/Inspection Service Points - How to Cope
with Intermittent Malfunctions P.00-15.

NO:

 Go to Step 3.

STEP 3. Check ambient air temperature sensor connector
A-44 and ETACS-ECU connector C-312 for loose, corroded
or damaged terminals, or terminals pushed back in the
connector.

Q:Are ambient air temperature sensor connector A-44 and

ETACS-ECU connector C-312 in good condition?

YES:

 Go to Step 4.

AIR CONDITIONING

55A-27

MANUAL A/C DIAGNOSIS

NO:

 Repair or replace the connector. Refer to GROUP 00E,

Harness Connector Inspection P.00E-2.

STEP 4. Check the wiring harness between ambient air
temperature sensor connector A-44 (terminals 2 and 1) and
ETACS-ECU connector C-312 (terminals 7 and 14).

Q:Is  the  wiring  harness  between  ambient  air  temperature

sensor connector A-44 (terminals 2 and 1) and ETACS-

ECU  connector  C-312  (terminals  7  and  14)  in  good

condition?

YES:

 Go to Step 5.

NO:

 Repair the wiring harness.

STEP 5. Check the ambient air temperature sensor.

ZC601994AA00

RESISTANCE
(k

W

)

TEMPERATURE ºC (ºF)

8

6

4

2

0

9

7

5

3

1

 -10

  0

 20

  40

(14)

(32)

(68)

(104)

 30

(86)

  10

(50)

10

Measure the resistance between connector terminals 1 and 2
under at least two different temperatures. The resistance values
should generally match those in the graph.

NOTE: 

The temperature at the check should not exceed the

range in the graph.

Q:Is the ambient air temperature sensor in good condition?

YES:

 Replace the A/C-ECU. Then go to Step 6.

NO:

 Replace the ambient air temperature sensor. Then go

to Step 6.

STEP 6. 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:

 The procedure is complete.

NO:

 Return to Step 1.

55A-28

AIR CONDITIONING

MANUAL A/C DIAGNOSIS

DTC B1079: Refrigerant Leaks

M15502000944USA0000010000

A/C-ECU

A/C PRESSURE
SENSOR

A/C Pressure Sensor Circuit 

ZC6008710014

Connector: A-50

A-50 (B)

ZC6008760001

Connector: C-109

C-109 (B)

 

DTC SET CONDITION
DTC B1079 will be set when the A/C pressure sensor
detects the refrigerant pressure of specified level or
less.

NOTE: 

When DTC B1079 is set, the A/C indicator of

A/C control panel flashes.

TECHNICAL DESCRIPTION (COMMENT)

Current trouble

｠

The refrigerant amount is not at the specified level,
or the wiring harness or connector between the A/
C-ECU and A/C pressure sensor, and the A/C-ECU
itself or A/C pressure sensor itself may be failed.

AIR CONDITIONING

55A-29

MANUAL A/C DIAGNOSIS

Past trouble

｠

If DTC B1079 is stored as a past trouble, carry out
diagnosis  with  particular  emphasis  on  wiring  and
connector(s)  between  the  A/C-ECU  and  the  A/C
pressure sensor. 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.

TROUBLESHOOTING HINT

｠

Malfunction of connector.

｠

Malfunction of the harness.

｠

Malfunction of the A/C pressure sensor.

｠

Malfunction of the A/C-ECU.

DIAGNOSIS

Required Special Tool:

｠

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

｠

MB991824: Vehicle Communication Interface (V.C.I.)

｠

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

｠

MB991910:  M.U.T.-III  Main  Harness  A  (Vehicles  with
CAN communication system)

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.
Recheck if the DTC is set.

(1)

Erase the DTC.

(2)

Turn the ignition switch to "ON" position.

(3)

Check if the DTC is set.

Q:Is the check result satisfactory?

YES:

 It can be assumed that this malfunction is

intermittent. Refer to GROUP 00, How to Use
Troubleshooting/Inspection Service Points - How to Cope
with Intermittent Malfunctions P.00-15.

NO:

 Go to Step 3.

55A-30

AIR CONDITIONING

MANUAL A/C DIAGNOSIS