2005 MITSUBISHI LANCER sensor

TROUBLESHOOTING
HEATER, AIR CONDITIONER AND VENTILATION55-24
STEP 10. Connector check: A-31 dual pressure
switch connector
Q: Is the check result normal?
YES :
Go to Step 11.
NO : Repair the connector.
STEP 11. Check the dual pressure switch
operation.
Refer to P.55-69.
Q: Is the dual pressure switch operating properly?
YES :
Go to Step 12.
NO : Replace the dual pressure switch.
STEP 12. Connector check: C-106 air thermo
sensor connector
Q: Is the check result normal?
YES :
Go to Step 13.
NO : Repair the connector.
STEP 13. Check the wiring harness between
C-106 air thermo sensor connector (terminals 4
and 5) and C-139 A/C-ECU connector (terminals 4
and 6).
•Check the air thermo sensor output and earth line
for open or short circuit.
Q: Is the check result normal?
YES :
Go to Step 14.
NO : Repair the wiring harness.
AC303825
Connector: A-31

AH
A-31 (BR)
Harness side
AC303816
Connector: C-106
AH

AC303816
Connector: C-106
AH

AC303818
Connector: C-139

AJ
Harness side
C-139 (B)
11 12657 8 9 103 421

TROUBLESHOOTING
HEATER, AIR CONDITIONER AND VENTILATION55-28
STEP 19. Check the magnetic clutch operation.
Refer to P.55-93.
Q: Can the sound of the magnetic clutch (click) be
heard?
YES :
Go to Step 20.
NO : Replace the compressor magnet clutch.
STEP 20. Check the refrigerant temperature
switch.
Refer to P.55-95.
Q: Is the refrigerant temperature switch operating
properly?
YES :
Go to Step 21.
NO : Replace the refrigerant temperature switch.
STEP 21. Check the air thermo sensor.
Refer to P.55-90.
Q: Is the air thermo sensor in good condition?
YES :
Go to Step 22.
NO : Replace the air thermo sensor.
STEP 22. Check the refrigerant level.
Refer to P.55-69.
Q: Is the refrigerant level correct?
YES :
Go to Step 23.
NO : Correct the refrigerant level (Refer to
On-vehicle Service P.55-70).
STEP 23. Replace the A/C-ECU.
Check that the air conditioner works normally.
Q: Is the check result normal?
YES :
This diagnosis is complete.
NO : Replace the engine-ECU or the
engine-A/T-ECU .

TROUBLESHOOTING
HEATER, AIR CONDITIONER AND VENTILATION55-67
CHECK AT ECU TERMINAL M1552010300527
12
345
678
9 10111213141516
AC300861AC

Terminal No. Check item Checking requirement Normal condition
1 Rear defogger switch Defogger switch: ON 0 V
Defogger switch: OFF System voltage
2 Inside/outside air selection
damper motor (outside air)When the damper is moved to
the inside air recirculation
position0 V
When the damper is moved to
the outside air inside air intake
positionSystem voltage
3 Inside/outside air selection
damper motor (inside air)When the damper is moved to
the inside air recirculation
positionSystem voltage
When the damper is moved to
the outside air inside air intake
position0 V
4 Output to the engine-A/T-ECU
(A/C1)A/C stopped 0 V
•A/C switch: ON
•Blower switch: ONSystem voltage
5 Output to the engine-A/T-ECU
(A/C2)When the A/C is under low load System voltage
When the A/C is under high
load0 V
6 Power supply to the A/C
illuminationLighting switch: ON System voltage
7---
8 Blower switch (lo) blower switch: lo System voltage
9---
10 Power supply to the ignition
switch (IG2)Ignition switch: ON System voltage
11 Earth to the A/C illumination Always 0 V
12 Earth Always 0 V
13 Air thermo sensor (outlet side) Sensor probe temperature 25°C
(1.5k ohm)2.2 V
14, 15 - - -
16 Earth to the air thermo sensor Always 0 V

TROUBLESHOOTING
HEATER, AIR CONDITIONER AND VENTILATION55-68
CHECK AT ECU TERMINAL M1552010300538
21
78
6 534
11
10912
AC304990
AB

Terminal No. Check item Checking requirement Normal condition
1 Output to the engine-A/T-ECU
(A/C1)A/C stopped 0 V
•A/C switch: ON
•Blower switch: ONSystem voltage
2 Output to the engine-A/T-ECU
(A/C2)When the A/C is under low load System voltage
When the A/C is under high
load0 V
3 Earth Always 0 V
4 Earth to the air thermo sensor Always 0 V
5 Power supply to the A/C
illuminationLighting switch: ON System voltage
6 Air thermo sensor (outlet side) Sensor probe temperature 25°C
(1.5k ohm)2.2 V
7 Power supply to the ignition
switch (IG2)Ignition switch: ON System voltage
8 Blower switch (lo) blower switch: lo System voltage
9 Rear defogger switch Defogger switch: ON 0 V
Defogger switch: OFF System voltage
10 Inside/outside air selection
damper motor (outside air)When the damper is moved to
the inside air recirculation
position0 V
When the damper is moved to
the outside air inside air intake
positionSystem voltage
11 Inside/outside air selection
damper motor (inside air)When the damper is moved to
the inside air recirculation
positionSystem voltage
When the damper is moved to
the outside air inside air intake
position0 V
12 Earth to the A/C illumination Always 0 V

HEATER UNIT, HEATER CORE, BLOWER ASSEMBLY AND EVAPORATOR UNIT
HEATER, AIR CONDITIONER AND VENTILATION55-81
HEATER UNIT, HEATER CORE, BLOWER ASSEMBLY
AND EVAPORATOR UNIT
REMOVAL AND INSTALLATION
M1552011600457
Pre-removal and Post-installation Operation
•Refrigerant draining and Refilling (Refer to Charging
P.55-70 and Discharging P.55-72).
•Engine coolant Draining and Refilling (Refer to GROUP
14, On vehicles service P.14-22).
•Instrument Panel Removal and Installation (Refer to
GROUP 52A, Instrument Panel P.52A-2).
•Air cleaner cover and air flow sensor assembly Removal
and Installation (Refer to GROUP 15, Air cleaner P.15-3).
•Rear console assembly Removal and Installation (Refer
to GROUP 52A, Rear console assembly P.52A-8).
•Front floor console assembly Removal and Installation
(Refer to GROUP 52A, Front floor console assembly
P.52A-6).
•Front seat assembly Removal and Installation (Refer to
GROUP 52A, Front seat assembly P.52A-24).
AC304861
1
2
3
4 5
6
7
8
N
9
AB
12 ± 2 N·m
6, 7O ring -Pipe coupling
A/C compressor oil:
SUN PAG 56
44 ± 10 N·m
44 ± 10 N·m
Removal steps
1. Front deck crossmember
2. Centre duct
3. Intake duct
•Foot duct (RH), Rear heater duct A
(RH) upper side (Refer to
P.55-101.)4. Blower assembly
5. Heater hose connection
<>6. Flexible suction hose connection
<>7. Liquid pipe B connection
8. O ring
9. Heater unitRemoval steps (Continued)

HEATER UNIT, HEATER CORE, BLOWER ASSEMBLY AND EVAPORATOR UNIT
HEATER, AIR CONDITIONER AND VENTILATION55-82
REMOVAL SERVICE POINT
<> FLEXIBLE SUCTION HOSE AND
LIQUID PIPE B DISCONNECTION
CAUTION
As the compressor oil and receiver are highly
moisture absorbent, use a non-porous material
to plug the hose and nipples.
To prevent the entry of dust or other foreign bodies,
plug the dismantled hose and the nipples of the
expansion valves.
HEATER UNIT
DISASSEMBLY AND REASSEMBLY

M1551005400224
AC304862
1
2
3
4
5
6
7
8
9
10
AB
4, 7O ring -Pipe coupling
A/C compressor oil:
SUN PAG 56
N
Disassembly steps
1. Foot duct (LH)
2. Heater core
3. Expansion valve
4. Joint
5. O ring6. Evaporator cover
7. Evaporator
8. Air thermo sensor clip
9. Air thermo sensor
10. Heater caseDisassembly steps (Continued)

HEATER UNIT, HEATER CORE, BLOWER ASSEMBLY AND EVAPORATOR UNIT
HEATER, AIR CONDITIONER AND VENTILATION55-83
DISASSEMBLY AND ASSEMBLY M1551005400235
AC304863
1
2
3
4
5
N
6
7
8
9
AB
6O ring -Pipe coupling
A/C compressor oil:
SUN PAG 56
Disassembly steps
1. Foot duct (RH)
2. Heater core
3. Expansion valve
4. O ring
5. Evaporator cover6. Evaporator
7. Air thermo sensor clip
8. Air thermo sensor
9. Heater caseDisassembly steps (Continued)

EVAPORATOR ASSEMBLY
HEATER, AIR CONDITIONER AND VENTILATION55-88
EVAPORATOR ASSEMBLY
REMOVAL AND INSTALLATION M1552003600355
REMOVAL SERVICE POINT
<> FLEXIBLE SUCTION HOSE AND
LIQUID PIPE B DISCONNECTION
CAUTION
As the compressor oil and receiver are highly
moisture absorbent, use a non-porous material
to plug the hose and nipples.
To prevent the entry of dust or other foreign bodies,
plug the dismantled hose and the nipples of the
expansion valves.
Pre-removal and Post-installation Operation
•Refrigerant draining and Refilling (Refer to Charging
P.55-70 and Discharging P.55-72).
•Air cleaner assembly <1300,1600> or Air cleaner and air
cleaner air flow sensor assembly <2000> Removal and
Installation (Refer to GROUP 15, Air cleaner P.15-3).
Y2346AU
1, 2, 4, 7
A/C compressor oil:
SUN PAG 56O ring
-Pipe coupling
2
101
3 4
7
6
5 98
8
12 ± 2 N·m
Removal steps
<>1. Flexible suction hose connection
<>2. Liquid pipe B connection
3. Expansion valve
4. Joint
•Glove box (Refer to GROUP 52A,
Instrument Panel P.52A-2).
•Engine-ECU or
Engine-A/T-ECU (Refer to
GROUP 13A, Engine-ECU and
Engine-A/T-ECU P.13A-401).
5. Joint duct
•Foot duct (LH), Rear heater duct
(LH), Rear heater duct (LH) (Refer
to P.55-101).
6. Evaporator cover
7. Evaporator
8. O ring 9. Air thermo sensor clip
10. Air thermo sensorRemoval steps (Continued)