Mitsubishi Outlander GS45X. Manual — part 1001

MANUAL A/C DIAGNOSIS

TSB Revision

HEATER, AIR CONDITIONING AND VENTILATION

55A-31

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).

• Check the sensor signal line and ground line for open and

short circuit.

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.
Measure the resistance between connector terminals 1 and 2
under at least two different temperatures. The resistance val-
ues 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.

AC209192

10

8

6

4

2

0

AB

10
(50)

30
(86)

Resistance

(k

Ω)

Temperature ºC (ºF)

0
(32)

40
(104)

-10
(14)

20
(68)

MANUAL A/C DIAGNOSIS

TSB Revision

HEATER, AIR CONDITIONING AND VENTILATION

55A-32

DTC B1079: Refrigerant Leaks

.

DTC SET CONDITION

DTC B1079 will be set when the A/C pressure sen-
sor 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.

AC702371

A/C-ECU

AB

A/C Pressure Sensor Circuit

A/C PRESSURE
SENSOR

AC702372AB

Connector: A-50

A-50 (B)

AC702208AH

Connector: C-109

C-109 (B)

MANUAL A/C DIAGNOSIS

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HEATER, AIR CONDITIONING AND VENTILATION

55A-33

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

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. 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.

ZC501967

AC404789

AC701411AB

MB991824

MB991827

MB991910

Data link
connector

MANUAL A/C DIAGNOSIS

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HEATER, AIR CONDITIONING AND VENTILATION

55A-34

STEP 3. Check A/C pressure sensor connector A-50 and
A/C-ECU connector C-109 for loose, corroded or damaged
terminals, or terminals pushed back in the connector.
Q: Are air A/C pressure sensor connector A-50 and

A/C-ECU connector C-109 in good condition?
YES : Go to Step 4.
NO : Repair or replace the connector. Refer to GROUP

00E, Harness Connector Inspection

P.00E-2

.

STEP 4. Check the wiring harness between A/C-ECU
connector C-109 (terminals 20, 16 and 19) and A/C
pressure sensor connector A-50 (terminals 3, 2 and 1).
NOTE: Also check intermediate connectors C-33 for loose, cor-
roded, or damaged terminals, or terminals pushed back in the
connector. If intermediate connector C-33 is damaged, repair or
replace the connector as described in GROUP 00E, Harness
Connector Inspection

P.00E-2

.

• Check the sensor signal line and ground line for open and

short circuit.

Q: Is the wiring harness between A/C-ECU connector

C-109 (terminals 20, 16 and 19) and A/C pressure sensor
connector A-50 (terminals 3, 2 and 1) in good condition?
YES : Go to Step 5.
NO : Repair the wiring harness.