display MITSUBISHI 380 2005 Workshop Manual

AUTO A/C DIAGNOSIS
HEATER, AIR CONDITIONING AND VENTILATION55-24
STEP 3. Using diagnostic tool , check data list item 20: Air
thermo sensor.
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) Ignition switch: ON
(3) Set diagnostic tool to the data reading mode for item 20: Air
thermo sensor.
Check that the passenger room temperature matches
the displayed value on the diagnostic tool while the
engine is cold.
NOTE: When this DTC is set and the system is fail-safe sta-
tus, the value of service data displays
6C.
(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 VENTILATION55-30
STEP 3. Using diagnostic tool , check data list item 63: Air
mix 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 63: Air
mix 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 VENTILATION55-43
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 VENTILATION55-60
DTC U1111: Multi-Center Display Unit Time-out
If DTC U1111 is set in the A/C-ECU, diagnose the
CAN main bus line.
Whenever the ECU is replaced, ensure that the
communication circuit is normal.
.
TROUBLE JUDGMENT
The A/C-ECU receives signals from the multi-center
display unit. If the ECU cannot receive the signal
r e l a t e d t o t h e m u l t i - c e n t e r d i s p l a y u n i t , D T C U 1111
will be set.
.
TECHNICAL DESCRIPTION (COMMENT)
Current trouble
Connector(s) or wiring harness in the CAN bus
lines between the A/C-ECU and the multi-center
display unit, the power supply system to the dis-
play unit, the display unit itself, or the A/C-ECU
may be defective.
Past trouble
W h e n D T C U 1111 i s s e t a s a p a s t t r o u b l e , c a r r y
out diagnosis with particular emphasis on con-
nector(s) or wiring harness in the CAN bus lines
between the A/C-ECU and the multi-center dis-
play unit, the power supply system to the display unit. If the connectors and wiring are normal, and
obviously the ECU or the multi-center display is
the cause of the trouble, replace the ECU or the
multi-center display. If in doubt, do not replace
the ECU or the display unit.
NOTE: For a past trouble, you cannot find it by
the diagnostic tool CAN bus diagnostics even if
there is a failure in the CAN bus lines. In this
case, refer to GROUP 00, How to Use Trouble-
shooting/Inspection Service Points
How to
Cope with Intermittent Malfunctions P.00-14.)
and check the CAN bus lines. You can narrow
down the possible cause of the trouble by refer-
ring to the DTC, which is set regarding the CAN
communication-linked ECUs (Refer to GROUP
54C
Explanation about the diagnostic tool CAN
bus diagnostics P.54C-6).
.
TROUBLESHOOTING HINTS
Malfunction of multi-center display unit
Malfunction of the A/C-ECU
Damaged harness wires and connectors
Refer to component locations GROUP-70
Refer to configuration diagrams GROUP-80
Refer to circuit diagrams GROUP-90
DIAGNOSIS
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 VENTILATION55-61
STEP 1. Using diagnostic tool , diagnose the CAN bus line.
To prevent damage to diagnostic tool (MUT-III), always turn
the ignition switch to the "LOCK" (OFF) position before
connecting or disconnecting diagnostic tool (MUT-III).
(1) Connect diagnostic tool to the data link connector.
(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-15).
STEP 2. Using diagnostic tool , read the Electronic control
unit diagnostic trouble code.
Check that the multi-center display unit sets a DTC.
(1) Turn the ignition switch to the "ON" position.
(2) Check for the DTC related to the multi-center display unit.
(3) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the check result satisfactory?
YES : Refer to GROUP 54A, multi-center display unit

Diagnosis P.54A-254.
NO : Go to Step 3.

AUTO A/C DIAGNOSIS
HEATER, AIR CONDITIONING AND VENTILATION55-62
STEP 3. Using diagnostic tool , check for any diagnostic
trouble code.
Check if a DTC, which relates to CAN communication-linked
systems below, is set.
ETACS-ECU
DTC indicating a time-out error of multi-center display unit
(1) Turn the ignition switch to the "ON" position.
(2) Check for a DTC related to the relevant system.
(3) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the check result satisfactory?
YES : Go to Step 4.
NO : Go to Step 5.
STEP 4. Recheck for diagnostic trouble code.
Check again if the DTC is set.
(1) Turn the ignition switch to the "ON" position.
(2) Check if the DTC is set.
(3) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the check result satisfactory?
YES : Replace the multi-center display unit. On completion,
check that the DTC is not reset.
NO : A poor connection, open circuit or other intermittent
malfunction is present in the CAN bus lines between
the multi-center display unit and the A/C-ECU (Refer
to GROUP 00, How to Use
Troubleshooting/Inspection Service Points
How to
Cope with Intermittent Malfunctions P.00-14).

AUTO A/C DIAGNOSIS
HEATER, AIR CONDITIONING AND VENTILATION55-63
STEP 5. Recheck for diagnostic trouble code.
Check again if the DTC is set.
(1) Turn the ignition switch to the "ON" position.
(2) Check if the DTC is set.
(3) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the check result satisfactory?
YES : Replace the A/C-ECU. On completion, check that the
DTC is not reset.
NO : A poor connection, open circuit or other intermittent
malfunction is present in the CAN bus lines between
the multi-center display unit and the A/C-ECU (Refer
to GROUP 00, How to Use
Troubleshooting/Inspection Service Points
How to
Cope with Intermittent Malfunctions P.00-14).

AUTO A/C DIAGNOSIS
HEATER, AIR CONDITIONING AND VENTILATION55-66
STEP 3. Using diagnostic tool , check for any diagnostic
trouble code.
Check if a DTC, which relates to CAN communication-linked
systems below, is set.
Combination meter
DTC indicating a time-out error related to the engine or
automatic transmission control system
ETACS
DTC indicating a time-out error related to the engine or
automatic transmission control system
Multi-center display unit
DTC indicating a time-out error related to the engine or
automatic transmission control system
(1) Turn the ignition switch to the "ON" position.
(2) Check for a DTC related to the relevant system.
(3) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the check result satisfactory?
YES : Go to Step 5.
NO : Go to Step 4.
STEP 4. Recheck for diagnostic trouble code.
Check again if the DTC is set.
(1) Turn the ignition switch to the "ON" position.
(2) Check if the DTC is set.
(3) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the check result satisfactory?
YES : Replace the Electronic control unit. On completion,
check that the DTC is not reset.
NO : There is an intermittent malfunction such as poor
engaged connector(s) or open circuit (Refer to
GROUP 00, How to Use Troubleshooting/Inspection
Service Points
How to Cope with Intermittent
Malfunctions P.00-14).

AUTO A/C DIAGNOSIS
HEATER, AIR CONDITIONING AND VENTILATION55-130
STEP 3. Using scan tool , check data list item 67: Photo
sensor.
(1) Connect scan tool to the data link connector.
(2) Start the engine.
(3) Set scan tool to the data reading mode for item 67: Photo
sensor.
Check that the display on the scan tool changes when
the photo sensor is covered with hands.
(4) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the sensor within the specified range?
YES : Go to Step 7.
NO : Go to Step 4.

AUTO A/C DIAGNOSIS
HEATER, AIR CONDITIONING AND VENTILATION55-133
DATA LIST REFERENCE TABLEM1554005100136
MUT-III
DIAGNOSTIC
TOOL DISPLAYITEM
NO.INSPECTION ITEM INSPECTION REQUIREMENT NORMAL VALUE
Inside
temperature
sensor59 Interior temperature
sensorIgnition switch: ON Inside air
temperature and
temperature
displayed on the
diagnostic tool are
identical.
Outside
temperature
sensor58 Outside temperature
sensorIgnition switch: ON Outside air
temperature and
temperature
displayed on the
diagnostic tool are
identical.
Air thermo sensor 20 Air thermo sensor Ignition switch: ON The temperature
measured behind
the evaporator
matches the
displayed value on
the diagnostic tool
while the engine is
cold.
Pressure sensor 61 A/C pressure sensor Ignition switch: ON Measured refrigerant
pressure is nearly
equal to the value
shown on the
diagnostic tool
(MPa).
Water
temperature
sensor62 Engine coolant
temperature sensor
(Data received by
CAN
Communication)Ignition switch: ON Engine coolant
temperature and
temperature
displayed on the
diagnostic tool are
identical.
Photo sensor 67 Photo sensor Ignition switch: ON Amount of light is
proportional to
voltage displayed on
the diagnostic tool.
Air mix
potentiometer63 Air mixing damper
control motor
potentiometerIgnition switch: ON Damper
positionOpening degree (V)
MAX. HOT Approx. 5
MAX. COOL Approx. 0
Air mix
potentiometer
(Target)64 Target value for air
mixing damper
control motor
potentiometerIgnition switch: ON Damper
positionOpening degree (V)
MAX. HOT Approx. 5
MAX. COOL Approx. 0