Mitsubishi 380. Manual - part 186

AUTO A/C DIAGNOSIS

HEATER, AIR CONDITIONING AND VENTILATION

55-40

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.

00DB076A

MB991910

DATA LINK

CONNECTOR

MB991824

MB991827

AUTO A/C DIAGNOSIS

HEATER, AIR CONDITIONING AND VENTILATION

55-41

DTC B1061, B1062: Mode Selection Damper Control Motor and Potentiometer

.

DTC SET CONDITION

• DTC B1061 or B1062 is set if there is an open or 

short circuit in the potentiometer input circuit, or if 
there is an open in the power circuit or ground cir-
cuit.

.

TECHNICAL DESCRIPTION (COMMENT)

Current trouble

• The A/C-ECU, the mode selection damper con-

trol motor and potentiometer, or connector(s) or 
wiring between the two may be defective.

Past trouble

• If DTC B1061 or B1062 is stored as a past trou-

ble, carry out diagnosis with particular emphasis 
on wiring and connector(s) between the A/C-ECU 
and the mode selection damper control motor 
and potentiometer. 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 mode selection damper control 

motor and potentiometer.

• Malfunction of the A/C-ECU.

• Refer to component locations GROUP-

70

• Refer to configuration diagrams GROUP-

80

• Refer to circuit diagrams GROUP-

90

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

25DB087A

CONNECTOR: C-102

C-102

AUTO A/C DIAGNOSIS

HEATER, AIR CONDITIONING AND VENTILATION

55-42

DIAGNOSIS

Required Special Tool:

•  : Diagnostic Tool (MUT-III Sub Assembly)

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

• MB991827: MUT-III USB Cable

• MB991910: MUT-III Main Harness A (Vehicles with CAN 

communication system)

STEP 1. Using diagnostic tool , diagnose the CAN bus line.
Use diagnostic tool  to diagnose the CAN bus lines.
(1) Connect diagnostic tool  to the data link connector.
(2) Turn the ignition switch to "ON" position.
(3) Diagnose the CAN bus line.

Q: Is the check result satisfactory?

YES : Go to Step 2.
NO :  Repair the CAN bus lines. (Refer to GROUP 54C, 

Diagnosis-Can Bus Diagnostic Chart 

P.54C-405

). 

Then go to Step 7.

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.00-14

.

NO :  Go to Step 3. 

00DB076A

MB991910

DATA LINK

CONNECTOR

MB991824

MB991827

AUTO A/C DIAGNOSIS

HEATER, AIR CONDITIONING AND VENTILATION

55-43

STEP 3. Using diagnostic tool , check data list item 55: Air 
outlet c/o potentiometer.

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 55: Air 

outlet c/o potentiometer.

• Check that the set position of the heater control matches 

the displayed position on the diagnostic tool.

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

Q: Is the sensor within the specified range?

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

00DB076A

MB991910

DATA LINK

CONNECTOR

MB991824

MB991827