2005 MITSUBISHI 380 heater

AUTO A/C DIAGNOSIS
HEATER, AIR CONDITIONING AND VENTILATION55-39
STEP 6. Check the air mixing damper control motor and
potentiometer.
Do not apply battery voltage when the damper is in the
MAX COOL or MAX HOT position.
Check the air mix damper control motor by the following proce-
dures.
Q: Are the air mixing damper control motor and
potentiometer in good condition?
YES : Replace the A/C-ECU. Then go to Step 7.
NO : Replace the air mixing damper control motor and
potentiometer. Then go to Step 7. LEVER POSITION BATTERY
CONNECTIONLEVER
OPERATION
At the MAX COOL
position
Connect
terminal 2 to the
positive battery
terminal
Connect
terminal 1 to the
negative battery
terminalThe lever moves
from the MAX
COOL position to
the MAX HOT
position
At the MAX HOT
position
Connect
terminal 1 to the
positive battery
terminal
Connect
terminal 2 to the
negative battery
terminalThe lever moves
from the MAX HOT
position to the MAX
COOL position

AUTO A/C DIAGNOSIS
HEATER, AIR CONDITIONING AND VENTILATION55-40
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.

AUTO A/C DIAGNOSIS
HEATER, AIR CONDITIONING AND VENTILATION55-41
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

AUTO A/C DIAGNOSIS
HEATER, AIR CONDITIONING AND VENTILATION55-42
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.

AUTO A/C DIAGNOSIS
HEATER, AIR CONDITIONING AND VENTILATION55-43
STEP 3. Using diagnostic tool , check data list item 55: Air
outlet c/o potentiometer.
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.

AUTO A/C DIAGNOSIS
HEATER, AIR CONDITIONING AND VENTILATION55-44
STEP 4. Check A/C-ECU connector C-15, C-16 and mode
selection damper control motor and potentiometer
connector C-102 for loose, corroded or damaged
terminals, or terminals pushed back in the connector.
Q: Are A/C-ECU connectors C-15, C-16 and mode selection
damper control motor and potentiometer connector
C-102 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.

AUTO A/C DIAGNOSIS
HEATER, AIR CONDITIONING AND VENTILATION55-45
STEP 5. Check the wiring harness between A/C-ECU
connectors C-15 (terminals 16 and 20), C-21 (terminal 21)
and mode selection damper control motor and
potentiometer connector C-102 (terminals 5, 7 and 3).
Q: Are the wiring harnesses between A/C-ECU connectors
C-10 (terminals 15, 11 and 10) and mode selection
damper control motor and potentiometer connector
C-102 (terminals 5, 7 and 3) in good condition?
YES : Go to Step 6.
NO : Repair the wiring harness. Then go to Step 7.

AUTO A/C DIAGNOSIS
HEATER, AIR CONDITIONING AND VENTILATION55-46
STEP 6. Check the mode selection damper control motor
and potentiometer.
Do not apply battery voltage when the damper is in the
FACE or DEF position.
(1) Operate the mode selection damper control motor as
described in the table below.
(2) Measure the resistances between connector terminals 3
and 5, and between 3 and 7, while the mode selection
damper control motor is running. The resistances should
change gradually within the standard value.
Standard value: 0.8 (DEF)
4.8 (FACE) k
Q: Are the mode selection damper control motor and
potentiometer in good condition?
YES : Replace the A/C-ECU. Then go to Step 7.
NO : Replace the mode selection damper control motor
and potentiometer. Then go to Step 7. LEVER POSITION BATTERY
CONNECTIONLEVER
OPERATION
At the FACE
position
Connect
terminal 2 to the
positive battery
terminal
Connect
terminal 1 to the
negative battery
terminalThe lever moves
from the FACE
position to the DEF
position
At the DEF position
Connect
terminal 1 to the
positive battery
terminal
Connect
terminal 2 to the
negative battery
terminalThe lever moves
from the DEF
position to the
FACE position