SPEED MITSUBISHI 380 2005 Service Manual

AUTO A/C DIAGNOSIS
HEATER, AIR CONDITIONING AND VENTILATION55-69
SYMPTOM PROCEDURES
INSPECTION PROCEDURE 1: When the Ignition Switch is "ON", the A/C does not Operate.
.
TECHNICAL DESCRIPTION (COMMENT)
The blower system or the compressor system may
be defective if there is no cool air coming from the
vents.
.
TROUBLESHOOTING HINTS
Malfunction of blower motor
Malfunction of A/C compressor
Refer to component locations GROUP-70
Refer to configuration diagrams GROUP-80
Refer to circuit diagrams GROUP-90
DIAGNOSIS
Check that the blower motor operation when the blower
switch is moved to the "HI" position.
(1) Turn the ignition switch to the "ON" position.
(2) Turn the blower speed selection dial to the blower operating
position.
Q: Does the blower motor operate when the speed
selection dial is turned to the blower operating
position?
YES : Refer to Inspection procedure 4 "When the A/C is
operating, temperature inside the passenger
compartment does not decrease (cool air not emitted)
P.55-75."
NO : Refer to Inspection procedure 5 "Blower fan and
motor do not turn P.55-89."
INSPECTION PROCEDURE 2: When the Air Outlet Changeover Control Knob is Moved to
DEFROSTER or DEFROSTER/FOOT Position, the A/C or the Inside/outside Air Changeover Damper
Motor does not operate.
.
TECHNICAL DESCRIPTION (COMMENT)
If the outside/inside air selection damper control
motor does not operate normally, the inside/outside
air changeover damper motor system may be defec-
tive.
.
TROUBLESHOOTING HINTS
Malfunction of the A/C-ECU
Malfunction of the outside/inside air selection
damper control motor
Damaged harness wires or connectors
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 VENTILATION55-100
STEP 17. Replace the power transistor.
Q: Does the blower motor operate normally?
YES : No action is necessary and testing is complete.
NO : Replace the A/C-ECU. Check that the air conditioning
works normally.
INSPECTION PROCEDURE 6: Front Blower Air Amount cannot be Changed.
.
CIRCUIT OPERATION
If the blower motor speed cannot be changed, the
power transistor circuit is suspected.
.
TROUBLESHOOTING HINTS
Malfunction of the power transistor
Malfunction of the front A/C-ECU
Damaged harness wires or connectors
Refer to component locations GROUP-70
Refer to configuration diagrams GROUP-80
Refer to circuit diagrams GROUP-90
DIAGNOSIS
Required Special Tool:
MB991223: Test Harness Set
STEP 1. Check blower power transistor connector C-104
for loose, corroded or damaged terminals, or terminals
pushed back in the connector.
Q: Is power transistor connector C-104 in good condition?
YES : Go to Step 2.
NO : Repair or replace the connector. Refer to GROUP
00E, Harness Connector Inspection P.00E-2.The
blower motor should operate normally.

AUTO A/C DIAGNOSIS
HEATER, AIR CONDITIONING AND VENTILATION55-134
Air outlet c/o
potentiometer55 Mode selection
damper control
motor potentiometerIgnition switch: ON Damper
positionOpening degree (V)
FA C E A p pr o x . 5
FOOT Approx. 3.75
FOOT/DEF. Approx. 2.5
DEF. Approx. 1.75
Air outlet c/o
potentiometer
(target)56 Target value for
mode selection
damper control
motor potentiometerIgnition switch: ON Damper
positionOpening degree (V)
FA C E A p pr o x . 5
FOOT Approx. 3.75
FOOT/DEF. Approx. 2.5
DEF. Approx. 1.75
In/out air
changeover
damper motor65 Outside/inside air
selection damper
control motorIgnition switch: ON Damper set
positionDamper position
Fresh air
positionFRESH
Air recirculation
positionRECIRC
Front blower fan 68 Blower motor Ignition switch: ON The actual air
volume (blower
motor speed)
corresponds to the
air volume shown on
the diagnostic tool.
Front blower
motor voltage 71 Blower motor Ignition switch: ON The air volume set
by the heater control
corresponds to the
value shown on the
diagnostic tool. (V)
Air conditioning
switch state1 Air conditioning
switchIgnition switch: ON Air conditioning
switch: ONDiagnostic tool
indication: "pressed"
Air conditioning
switch: OFFDiagnostic tool
indication: "release"
Rear defogger
switch state7 Rear window
defogger switchIgnition switch: ON Rear window
defogger
switch: ONDiagnostic tool
indication: "pressed"
Rear window
defogger
switch: OFFDiagnostic tool
indication: "release"
Refrigerant
pressure73 Refrigerant pressure Ignition switch: ON The diagnostic tool
indication is normal MUT-III
DIAGNOSTIC
TOOL DISPLAYITEM
NO.INSPECTION ITEM INSPECTION REQUIREMENT NORMAL VALUE

AUTO A/C DIAGNOSIS
HEATER, AIR CONDITIONING AND VENTILATION55-135
Temperature
setting23 Temperature setting
actualIgnition switch: ON The actual setting
corresponds with
diagnostic tool
display.
Vehicle speed 26 Actual vehicle speed Ignition switch: ON The vehicle speed
corresponds with
diagnostic tool
display.
A/C compressor
drive request27 Compressor clutch Engine: ON
Compressor:
ONDiagnostic tool
indication: "ON"
Compressor:
OFFDiagnostic tool
indication: "OFF"
Illumination 15 Display lighting Ignition switch: ON
Lights: ON
Diagnostic tool
indication: "ON"
Lights: OFF
Diagnostic tool
indication: "OFF"
Engine speed 23 Actual engine speed Engine: ON The engine speed
corresponds with
diagnostic tool
display.
In/out air select
switch state3 In/out air select
switch Ignition switch: ON In/out air
switch: ONDiagnostic tool
indication: "pressed"
In/out air
switch: OFFDiagnostic tool
indication: "release"
Rear defogger
relay72 Rear defogger relay Ignition switch: ON
Rear defogger:
ONDiagnostic tool
indication: "ON"
Rear defogger:
OFFDiagnostic tool
indication: "OFF" MUT-III
DIAGNOSTIC
TOOL DISPLAYITEM
NO.INSPECTION ITEM INSPECTION REQUIREMENT NORMAL VALUE

AUTO A/C DIAGNOSIS
HEATER, AIR CONDITIONING AND VENTILATION55-136
ACTUATOR TEST REFERENCEM1554005200133
MUT-III DIAGNOSTIC
TOOL DISPLAYITEM NO. INSPECTION ITEM DRIVE CONTENT
Blower fan: OFF 83 Blower motor OFF
Blower fan: Middle 84 Middle speed
Blower fan: High 85 High speed
Air mix damper motor:
0%42 Air mixing damper control motor Opening degree: approx.
0% (Max cool)
Air mix damper motor:
100%43 Opening degree: approx.
100% (Max hot)
Air outlet c/o damper:
FA C E70 Mode selection damper control
motorFA C E
Air outlet c/o damper: Bi_
Level67 FOOT/FACE
Air outlet c/o damper:
FOOT71 FOOT
Air outlet c/o damper:
DEF/FOOT69 DEF/FOOT
Air outlet c/o damper:
DEF68 DEF
Idle up request: high load 74 Idle speed HIGH idle up
Idle up request: low load 75 LOW idle up
Idle up request: OFF 76 OFF
Rear defogger switch:
OFF40 Rear window defogger switch Rear window defogger: OFF
Rear defogger switch:
ON41 Rear window defogger: ON
Idle up request: OFF 50 Idle up operation Idle up: OFF
Idle up request: low load 51 Idle up: low load
Idle up request: high load 52 Idle up: high load
Condenser: 0% 77 Condenser fan OFF
Condenser: 50% 79 Middle speed
Rheostat: 0% 80 Rheostat- Illumination control OFF
Rheostat: 100% 81 Full duty
Rheostat: 50% 82 Half duty

AUTO A/C DIAGNOSIS
HEATER, AIR CONDITIONING AND VENTILATION55-138
16 Potentiometer power supply Ignition switch: ON 5 V
17 Power transistor (BASE) When the blower speed
selection dial shows Maximum
air volume.1 V
18 Power transistor
(COLLECTOR)When the blower speed
selection dial shows Maximum
air volume.12.1 V
19 Photo sensor Ignition switch: ON 5 V
20 Sensors and potentiometers
groundAlways 0 V
21 Mode selection damper control
motor potentiometer inputWhen the damper is moved to
the FACE position. 4 V
22 Interior temperature sensor Ignition switch: ON 5 V
23 Ambient temperature sensor
inputWhen sensor temperature is
25
C (77F) [4 k]1.9 V
24 Air thermo sensor input When sensor temperature is
25
C (77F) [1.5 k]2.2 V
25 Photo sensor ground Ignition switch: ON 0 V
26 A/C pressure sensor at 2.6 MPa 3.9 V
27 Ground Always 0 V
28 Power supply to the ignition
switch (IG2)Ignition switch: ON Battery positive voltage
29 Air mixing damper control motor
potentiometer inputWhen the damper door is
moved to the MAX. HOT
position.1.4 V
30 Illumination ground Always 0 V
31 ILL power supply Lighting switch: ON Battery positive voltage
34 A/C pressure sensor ground Always 0 V
36 Power supply to the ignition
switch (ACC)Ignition switch: ON Battery positive voltage TERMINAL
NO.CHECK ITEM CHECKING REQUIREMENTS NORMAL CONDITION

SPECIAL TOOLS
HEATER, AIR CONDITIONING AND VENTILATION55-140
A: MB991824
B: MB991827
C: MB991910
D: MB991911
E: MB991914
F: MB991825
G: MB991826
MUT-III Sub
Assembly
A: Vehicle
communicatio
n interface
(V.C.I.)
B: MUT-III USB
cable
C: MUT-III main
harness A
(Vehicles with
CAN
communicatio
n system)
D: MUT-III main
harness B
(Vehicles
without CAN
communicatio
n system)
E: MUT-III main
harness C (for
Daimler
Chrysler
models only)
F: MUT-III
measurement
adapter
G: MUT-III
Trigger
HarnessMB991824-KIT
NOTE: . G:
MB991826 MUT-III
Trigger Harness is not
necessary when
pushing V.C.I.
ENTER key.Checking diagnostic trouble codes
For vehicles with CAN
communication, use MUT-III
main harness A to send
simulated vehicle speed. If you
connect MUT-III main harness B
instead, the CAN
communication does not
function correctly. TOOL TOOL NUMBER
AND NAMESUPERSESSION APPLICATION

ON-VEHICLE SERVICE
HEATER, AIR CONDITIONING AND VENTILATION55-143
PERFORMANCE TEST M1552001400526
The vehicles to be tested should be parked out of direct sun-
light.
1. Close the high and low-pressure valve of the gauge
manifold.
2. Connect the charging hose (blue) to the low-pressure valve
and connect the charging hose (red) to the high-pressure
valve of the gauge manifold.
3. Install the quick joint (for low-pressure) to the charging hose
(blue), and connect the quick joint (for high-pressure) to the
charging hose (red).
To connect the quick joint, press section A firmly
against the service valve until a click is heard.
When connecting, run your hand along the hose while
pressing to ensure that there are no bends in the hose.
4. Connect the quick joint (for low-pressure) to the
low-pressure service valve and connect the quick joint (for
high-pressure) to the high-pressure service valve.
NOTE: The high-pressure service valve is on the A/C pipe
and the low-pressure service valve is on the suction hose.
5. Start the engine.
6. Set the A/C controls as follows:
A/C switch: A/C ON position
Mode selection: FACE position
Temperature control: MAXIMUM COOLING position
Air selection: RECIRCULATION position
Blower switch: Maximum air volume
7. Adjust engine speed to 1,500 r/min with A/C clutch engaged.
8. Engine should be warmed up with doors and windows
closed.
9. Insert a thermometer in the center air outlet and operate the
engine for 20 minutes.
NOTE: If the A/C clutch cycles, take the reading before the
clutch disengages.
10.Note the discharge air temperature.
PERFORMANCE TEMPERATURE CHART
GARAGE AMBIENT AIR TEMPERATURE C
(
F)20 (68) 25 (77) 30 (86) 35 (95)
Discharge air temperature
C (F) 1 (34) 6 (43)
Compressor high pressure kPa (psi) 1275 (185)
1863 (270)
Compressor low pressure kPa (psi) 49 (7.1)
294 (42.7)

ON-VEHICLE SERVICE
HEATER, AIR CONDITIONING AND VENTILATION55-146
Sharper bends will reduce the flow of refrigerant. The flexible
hose lines should be routed so that they are at least 80 mm
(3.1 inches) from the exhaust manifold. It is good practice to
inspect all flexible hose lines at least once a year to make sure
they are in good condition and properly routed.
On standard plumbing fittings with O-rings, these O-rings are
not reusable.
AIR CONDITIONING NOISE TEST
You must first know the conditions when the noise occurs.
These conditions are: weather, vehicle speed, in gear or neu-
tral, engine temperature or any other special conditions.
Noises that develop during A/C operation can often be mislead-
ing. For example: what sounds like a failed front bearing or
connecting rod, may be caused by loose bolts, nuts, mounting
brackets, or a loose clutch assembly. Verify accessory drive
belt tension (power steering or generator).
Improper accessory drive belt tension can cause a misleading
noise when the compressor is engaged and little or no noise
when the compressor is disengaged.
Drive belts are speed-sensitive. That is, at different engine
speeds, and depending upon belt tension, belts can develop
unusual noises that are often mistaken for mechanical prob-
lems within the compressor.
Normal air conditioning operation will generate some level of
operational noise. To judge what is normal and abnormal,
requires an understanding of the air conditioning system. This
test is to detail the most common noise complaints and the
repair methods.
VEHICLE CONDITION
1. Ensure the system is not over or under charged.(Refer to
P.55-142).
2. Tighten all compressor mounting bolts, clutch mounting
bolts and compressor drive belt.
3. Inspect layout of the system is correct, ie no interference
between hoses and all retaining clamps are in place.

ON-VEHICLE SERVICE
HEATER, AIR CONDITIONING AND VENTILATION55-147
TEST PROCEDURES
1. Select a quiet area for testing.
2. Duplicate problem (customer complaint) as much as
possible.
3. Judge if the noise is abnormal (ie. it is important to
understand the characteristics of the vehicle and its normal
state to judge what is abnormal) - Compare with similar
vehicle if necessary.
4. Detail what and how noise occurs.
5. Find the noise source and verify its transmission by isolating
the subject part from the vehicle.
6. Repair the problem.
7. Explain and report your findings.
DETAILS OF A/C NOISE
POSSIBLE CAUSES, CHECKS AND REPAIRS
NOISE DESCRIPTION WHEN IT OCCURS SOURCE OF NOISE
Rumbling (Bearing noise) With A/C On or Off Magnetic clutch, idler pulley
Clang-Clack noise When compressor is engaged Magnetic clutch operation
Squawking (Belt sliding noise) When compressor is engaged V-belt
Whistling or Whooping noise Immediately after the A/C is
engaged.Expansion valve
Hissing or swishing noise When A/C is engaged, but
decreases as flow is stable Refrigerant flow
Rattling (Internal compressor) When compressor is operating Compressor internal part
Wooing (Resonant noise) With A/C On, occurs at certain
speed.Resonance of accessories
Cooing (Discharge pulsation
noise)With A/C On or Off Resonating noise with the vehicle
body
NOISE DESCRIPTION POSSIBLE CAUSE CHECK REPAIR
Rumbling (Bearing
noise)Bearing damage in rotor Manual rotation of bearing Replace compressor
Rotor slipping on boss Wear on compressor boss
surfaceReplace compressor
Bearing damage in pulley Check alignment between
pulleysReplace compressor
Clang-Clack noise Hub to stator misaligned Wear on inner clutch face Replace compressor
Gap between clutch
surface is too largeCheck Air gap is within
specificationReplace compressor
Squawking (Belt sliding
noise)Oil/water between the belt
and rotor surfaceOil and water
contaminationClean
Low belt tension Belt tension Reset or Replace belt and
set tension to correct
specification
Whistling or Whooping
noiseVibration of expansion
valveExpansion valve Replace TX valve