Mitsubishi 380. Manual - part 179

AUTO A/C DIAGNOSIS

HEATER, AIR CONDITIONING AND VENTILATION

55-12

STEP 3. Using diagnostic tool , check data list item 59: 
Inside temperature sensor.

CAUTION

To prevent damage to diagnostic tool , always turn the 
ignition switch to the "LOCK" (OFF) position before con-
necting or disconnecting diagnostic tool .
(1) Connect diagnostic tool  to the data link connector.
(2) Start the engine.
(3) Set diagnostic tool  to the data reading mode for item 59: 

Inside temperature sensor.

• Check that the interior temperature matches the dis-

played value on the diagnostic tool.

NOTE: When this DTC is set and the system is in fail-safe 
status, the value of service data displays 25

°C.

(4) Turn the ignition switch to the "LOCK" (OFF) position.

Q: Does the interior temperature match the displayed value 

on the diagnostic tool?
YES : Replace the A/C-ECU. Then go to Step 7.
NO :  Go to Step 4.

00DB076A

MB991910

DATA LINK

CONNECTOR

MB991824

MB991827

AUTO A/C DIAGNOSIS

HEATER, AIR CONDITIONING AND VENTILATION

55-13

STEP 4. Check A/C-ECU connector C-15, C-16 and interior 
temperature sensor connector C-123 for loose, corroded 
or damaged terminals, or terminals pushed back in the 
connector.
Q: Are A/C-ECU connectors C-15, C-16 and interior 

temperature sensor connector C-123 in good condition?
YES : Go to Step 5.
NO :  Repair or replace the connector. Refer to GROUP 

00E, Harness Connector Inspection 

P.00E-2

. Then go 

to Step 7.

25DB070A

CONNECTORS: C-15, C-16

C-16 (B)

HARNESS SIDE

C-16

C-15

C-15 (B)

HARNESS SIDE

21

22

23

24

25

26

27

28

29

30

31

32

33

34

35

36

25DB071A

CONNECTOR: C-123

HARNESS SIDE

AUTO A/C DIAGNOSIS

HEATER, AIR CONDITIONING AND VENTILATION

55-14

STEP 5. Check the wiring harness between A/C-ECU 
connector C-15 (terminals 20), C-16 (terminals 22) and 
interior temperature sensor connector C-123 (terminals 1 
and 2).
Q: Are the wiring harnesses between A/C-ECU connector 

C-15 (terminals 20), C-16 (terminals 22) and interior 
temperature sensor connector C-123 (terminals 1 and 2) 
in good condition?
YES : Go to Step 6.
NO :  Repair the wiring harness. Then go to Step 7.

25DB070A

CONNECTORS: C-15, C-16

C-16 (B)

HARNESS SIDE

C-16

C-15

C-15 (B)

HARNESS SIDE

21

22

23

24

25

26

27

28

29

30

31

32

33

34

35

36

25DB072A

CONNECTORS: C-03, C-123

C-03

C-123

JUNCTION BLOCK SIDE

C-03

HARNESS SIDE

C-123

AUTO A/C DIAGNOSIS

HEATER, AIR CONDITIONING AND VENTILATION

55-15

STEP 6. Check the interior temperature sensor.
(1) Disconnect interior temperature sensor connector C-123.

(2) When the resistance between the sensor terminals is 

measured under two or more temperature conditions, the 
resistance should approximately satisfy the illustrated 
values.

NOTE: The temperature conditions when checking should 
not exceed the range shown in the diagram.

Q: Is the interior temperature sensor in good condition?

YES : Replace the A/C-ECU. Then go to Step 7.
NO :  Replace the interior temperature sensor. Then go to 

Step 7.

STEP 7. Recheck for diagnostic trouble code.
Check again if the DTC is set.
(1) Connect diagnostic tool  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.

25DB071A

CONNECTOR: C-123

HARNESS SIDE

AC103488 AC

RESISTANCE

   (kΩ)

TEMPERATURE ˚C (˚F)

20

15

10

5

0

0

20

40

60

80

-10

(32) (68) (104) (140) (176)

(14)

00DB076A

MB991910

DATA LINK

CONNECTOR

MB991824

MB991827