2005 MITSUBISHI 380 Workshop Manual

GENERAL DESCRIPTION
HEATER, AIR CONDITIONING AND VENTILATION55-4
OPERATION
.
CONDENSER FAN AND RADIATOR FAN
CONTROL
The ECU judges the required revolution speed of
radiator fan motor and condenser fan motor using
the input signals transmitted from A/C switch, output
shaft speed sensor and engine coolant temperature
sensor. The ECU activates the fan control relays to
drive the radiator fan motor and condenser fan
motor.
.
COMPRESSOR CONTROL
When operating the air conditioning switch
The air thermo sensor, which senses the temper-
ature of the air flowing out of the evaporator,
deactivates the compressor at 3
C (37.4F) or
below.
The dual pressure switch turns OFF when the
refrigerant pressure becomes excessively high or
low, thus protecting the compressor circuit (See
Table below).
When the air thermo sensor is activated, and the
ignition switch, blower switch, and air condition-
ing switch are ON, the A/C compressor clutch
relay is energized.
When operating the mode selection dial
The air conditioning will work when the mode
selection dial is set to the "Defroster" or
"Defroster/foot" position, or the temperature con-
trol dial is set to the "MAX A/C" position. In other
dial positions, when the air conditioning switch is
turned on, the air conditioning will work.
A/C Compressor Clutch Relay ON Conditions
Ignition switch (IG2) ONNOTE: A/C compressor clutch relay is
de-energized when any one switch, sensor
or control unit shown on the left turns off.
NOTE: The components marked by
*
communicate with the ECU. If the air thermo
sensor detects a temperature of 3
C
(37.4
F), the A/C-ECU will turn off the A/C
compressor clutch relay. Blower switch ON
Air conditioning switch, mode selection dial
defroster, defroster/foot position or temperature
control MAX A/CON
Air thermo sensor*
Pressure detected
by A/C pressure
sensor2940 kPa or less (If the
refrigerant pressure exceeds
2940 kPa, A/C compressor
clutch relay is not ON
condition until the refrigerant
pressure has been measured
up to 2350 kPa or less.)ON
190 kPa or more (If the
refrigerant pressure falls short
of 190 kPa, A/C compressor
clutch relay is not ON
condition until the refrigerant
pressure has been measured
up to 220 kPa or more.)
A/C compressor clutch relay driving transistor (within
ecu)ON

AUTO A/C DIAGNOSIS
HEATER, AIR CONDITIONING AND VENTILATION55-5
AUTO A/C DIAGNOSIS
INTRODUCTIONM1554006200062
After air is taken in through the damper, it is fed to
the evaporator by the blower fan and motor and
cooled. The air cooled by the air mix damper is
mixed appropriately with the warmed air to achieve a
comfortable temperature. If the A/C does not operate
or the cooled air is not discharged, the system com-
ponents or relay may be faulty.
AUTOMATIC AIR CONDITIONING TROUBLESHOOTING STRATEGYM1554004700157
Use these steps to plan your diagnostic strategy. If
you follow them carefully, you will be sure that you
have exhausted most of the possible ways to find a
heater, air conditioning and ventilation fault.
1. Gather information from the customer.2. Verify that the condition described by the
customer exists.
3. Find the malfunction by following the Symptom
Chart.
4. Verify malfunction is eliminated.
DIAGNOSTIC FUNCTIONM1552019800046
HOW TO CONNECT THE DIAGNOSTIC TOOL
(MUT-III)
Required Special Tools:
: 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)
To prevent damage to diagnostic tool , always turn the
ignition switch to the "LOCK" (OFF) position before con-
necting or disconnecting diagnostic tool .
1. Ensure that the ignition switch is at the "LOCK" (OFF)
position.
2. Start up the personal computer.
3. Connect special tool MB991827 to special tool MB991824
and the personal computer.
4. Connect special tool MB991910 to special tool MB991824
5. Connect special tool MB991910 to the data link connector.
6. Turn the power switch of special tool MB991824 to the "ON"
position.
NOTE: When the special tool MB991824 is energized, the
special tool MB991824 indicator light will be illuminated in a
green color.
7. Start the MUT-III system on the personal computer.
NOTE: Disconnecting the diagnostic tool special tool
MB991824 is the reverse of the connecting sequence, making
sure that the ignition switch is at the "LOCK" (OFF) position.

AUTO A/C DIAGNOSIS
HEATER, AIR CONDITIONING AND VENTILATION55-6
HOW TO READ AND ERASE DIAGNOSTIC
TROUBLE CODES
Required Special Tools:
: 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)
To prevent damage to diagnostic tool , always turn the
ignition switch to the "LOCK" (OFF) position before con-
necting or disconnecting diagnostic tool .
NOTE: If the battery voltage is low, diagnostic trouble codes will
not be output. Check the battery if diagnostic tool does not dis-
play.
1. Connect the diagnostic tool to the data link connector.
2. Turn the ignition switch to the "ON" position.
3. Select "Interactive Diagnosis" from the start-up screen.
4. Select "System Select."
5. Choose "AUTO A/C" from the "BODY" tab.
6. Select "MITSUBISHI."
7. Select "Diagnostic Trouble Code."
8. If a DTC is set, it is shown.
9. Choose "Erase DTC" to erase the DTC.
HOW TO READ DATA LIST
Required Special Tools:
: 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)

AUTO A/C DIAGNOSIS
HEATER, AIR CONDITIONING AND VENTILATION55-7
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 the diagnostic tool to the data link connector.
2. Turn the ignition switch to the "ON" position.
3. Select "Interactive Diagnosis" from the start-up screen.
4. Select "System Select."
5. Choose "AUTO A/C" from the "BODY" tab.
6. Select "MITSUBISHI."
7. Select "Data List."
8. Choose an appropriate item and select the "OK" button.
HOW TO PERFORM ACTUATOR TEST
Required Special Tools:
: 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)
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 the diagnostic tool to the data link connector.
2. Turn the ignition switch to the "ON" position.
3. Select "Interactive Diagnosis" from the start-up screen.
4. Select "System Select."
5. Choose "AUTO A/C" from the "BODY" tab.
6. Select "MITSUBISHI."
7. Choose "Actuator Test" from "AUTO A/C" screen.
8. Choose an appropriate item and select the "OK" button.

AUTO A/C DIAGNOSIS
HEATER, AIR CONDITIONING AND VENTILATION55-8
HOW TO DIAGNOSE THE CAN BUS LINE
Required Special Tools:
: Diagnostic Tool (MUT-III Sub Assembly)
MB991824: Vehicle Communication Interface (V.C.I.)
MB991827: MUT-III USB Cable
MB991910: MUT-III Main Harness A
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. Turn the ignition switch to the "ON" position.
3. Select "CAN bus diagnosis" from the start-up screen.
4. When the vehicle information is displayed, confirm that it
matches the vehicle whose CAN bus lines will be
diagnosed.
If they match, go to step 8.
If not, go to step 5.
5. Select "view vehicle information" button.
6. When the vehicle information is displayed, confirm again
that it matches the vehicle which is diagnosed CAN bus line.
If they match, go to step 8.
If not, go to step 5.
7. Press the "OK" button.
8. When the options are displayed, choose the options (mark
the check) and then select "OK".

AUTO A/C DIAGNOSIS
HEATER, AIR CONDITIONING AND VENTILATION55-9
DIAGNOSTIC TROUBLE CODE CHART M1554004900214
During diagnosis, a DTC code associated with
other system may be set when the ignition switch
is turned on with connector(s) disconnected. On
completion of repairs, confirm all systems for
DTC code(s). If DTC code(s) are set, erase them
all.
DIAGNOSTIC
TROUBLE CODE
NO.DIAGNOSTIC ITEM REFERENCE
PA G E
B1001 Interior temperature sensor system (short circuit)
P.55-10
B1002 Interior temperature sensor system (open circuit)
P.55-10
B1011 Ambient air temperature sensor system (short circuit)
P.55-16
B1012 Ambient air temperature sensor system (open circuit)
P.55-16
B1021 Air thermo sensor system (short circuit)
P.55-22
B1022 Air thermo sensor system (open circuit)
P.55-22
B1041 Air mixing damper control motor and potentiometer (potentiometer
system shorted to its power supply)P.55-28
B1042 Air mixing damper control motor and potentiometer (potentiometer
system shorted to its ground)P.55-28
B1045 Air mixing damper control motor and potentiometer (activating
system failure)P.55-35
B1061 Mode selection damper control motor and potentiometer
(potentiometer system shorted to its power supply)P.55-41
B1062 Mode selection damper control motor and potentiometer
(potentiometer system shorted to its ground)P.55-41
B1065 Mode selection damper control motor and potentiometer (activating
system failure)P.55-48
U1073 Bus off
P.55-54
U1100
Electronic control unit time-out (related to engine)P.55-56
U 1111 M u l t i - c e n t e r d i s p l a y u n i t ( m i d d l e g r a d e t y p e ) t i m e - o u t
P.55-60
U1120 Failure information on Electronic control unit (related to engine)
P.55-64

AUTO A/C DIAGNOSIS
HEATER, AIR CONDITIONING AND VENTILATION55-10
DIAGNOSTIC TROUBLE CODE PROCEDURES
DTC B1001, B1002: Interior Temperature Sensor System.
DTC SET CONDITION
DTC B1001 is set if there is a short circuit in the
interior temperature sensor input circuit.
DTC B1002 is set if there is a defective connector
connection, or if there is an open circuit in the
harness.
.
TECHNICAL DESCRIPTION (COMMENT)
Current trouble
The A/C-ECU, the interior air temperature sensor,
or connector(s) or wiring between the two may be
defective.Past trouble
If DTC B1001 or B1002 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 interior air temperature sensor. If the con-
nectors 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 interior temperature sensor.
Malfunction of the A/C-ECU.
Refer to component locations GROUP-70
Refer to configuration diagrams GROUP-80
Refer to circuit diagrams GROUP-90
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)

AUTO A/C DIAGNOSIS
HEATER, AIR CONDITIONING AND VENTILATION55-11
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.