2005 MITSUBISHI LANCER ac compressor

TROUBLESHOOTING
HEATER, AIR CONDITIONER AND VENTILATION55-21
COMMENTS ON TROUBLE SYMPTOM
If cool air is not distributed when the A/C switch is on,
the air thermo sensor or the A/C compressor relay
system may be defective.
TROUBLESHOOTING HINTS
•Improper amount of refrigerant
•Malfunction of the air thermo sensor
•Malfunction of the dual pressure switch
•Malfunction of the A/C compressor relay
•Malfunction of the A/C refrigerant temperature
switch
•Malfunction of the magnetic clutch
•Malfunction of the manual air conditioner control
panel (A/C-ECU)
•Damaged the wiring harness or connectors
•Malfunction of the engine-ECU or the
engine-A/T-ECU
DIAGNOSIS
STEP 1. Check the defogger and outside/inside
air selection damper control motor operation.
Q: Do the defogger and outside/inside air selection
damper control motor work normally?
YES :
Go to Step 2.
NO : Refer to Inspection procedure 10
"Malfunction of the A/C-ECU power supply
system P.55-56 ."
STEP 2. Check the blower motor operation.
Q: Does the blower motor work normally?
YES :
Go to Step 3.
NO : Refer to Inspection procedure 5 "Blower fan
and motor do not turn P.55-29."
STEP 3. Check the A/C compressor.
Check the A/C compressor for compressor oil leaks.
Q: Is the check result satisfactory?
YES :
Go to Step 4.
NO : Replace the A/C compressor or the
expansion valve.
STEP 4. Connector check: B-114 A/C compressor
connector and C-123 engine-ECU connector
or C-122 engine-A/T-ECU connector
Q: Is the check result normal?
YES :
Go to Step 5.
NO : Repair the connector.
AC303786
Connector: B-114
<4G1-R.H.D.>
AB
Harness side
B-114 (B)
AC303794
Connector: B-114
<4G6-R.H.D.>
AB
Harness side
B-114 (B)
AC303817
Connectors: C-122 , C-123
AF

C-122C-122 (GR)
C-123 (Y)
C-123 Harness side

TROUBLESHOOTING
HEATER, AIR CONDITIONER AND VENTILATION55-22
STEP 5. Voltage measurement at the B-114 A/C
compressor connector.
(1) Disconnect the connector, and measure at the
wiring harness side.
(2) Turn the ignition switch to the "ON" position.(3) Disconnect engine-ECU connector C-123, and
earth terminal 8.
(4) Disconnect engine-A/T-ECU connector C-122,
and earth terminal 20.
(5) Measure the voltage between terminal 1 and
body earth.
OK: System voltage
Q: Is the check result normal?
YES :
Go to Step 6.
NO : Refer to Inspection procedure 11 "A/C
compressor power supply system P.55-59."
AC303786
Connector: B-114
<4G1-R.H.D.>
AB
Harness side
B-114 (B)
AC303794
Connector: B-114
<4G6-R.H.D.>
AB
Harness side
B-114 (B)
AC303817
Connectors: C-122 , C-123
AF

C-122C-122 (GR)
C-123 (Y)
C-123 Harness side
AC305159 Connector C-123
(Harness side)AB
AC305161
Connector C-122
(Harness side)
AB
AC301541EW
Connector B-114
(Harness side)
1

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 VENTILATION55-59
INSPECTION PROCEDURE 11: A/C Compressor power supply system.
A/C
COMPRESSOR
RELAY
A/C
COMPRESSOR
A/C
REFRIGERANT
TEMPERATURE
SWITCH
MAGNETIC
CLUTCH
IGNITION
SWITCH (IG2)
ENGINE-ECU BATTERY
RELAY
BOX
ENGINE-A/T-ECU
Wire colour code
B : Black LG : Light green G : Green L : Blue
W : White Y : Yellow SB : Sky blue BR : Brown
O : Orange GR : Gray R : Red P : Pink V : Violet
: M/T
: A/TNOTE
A/C Compressor Circuit

TROUBLESHOOTING
HEATER, AIR CONDITIONER AND VENTILATION55-60
COMMENTS ON TROUBLE SYMPTOM
If the power is not supplied to the A/C compressor,
the A/C compressor circuit system may be
defective..
TROUBLESHOOTING HINTS
•Malfunction of the A/C compressor relay
•Damaged the wiring harness or connectors
DIAGNOSIS
STEP 1. Connector check: B-17X A/C
compressor relay connector
Q: Is the check result normal?
YES :
Go to Step 2.
NO : Repair the connector.
STEP 2. Check the A/C compressor relay
continuity.
Refer to P.55-75.
Q: Is the A/C compressor relay in good condition?
YES :
Go to Step 3.
NO : Replace the A/C compressor relay.
STEP 3. Voltage measurement at B-17X A/C
compressor relay connector.
(1) Remove the relay, and measure at the relay box
side.
(2) Turn the ignition switch to the "ON" position.
(3) Measure the voltage between terminal 2 and
body earth.
OK: System voltage
Q: Is the check result normal?
YES :
Go to Step 6.
NO : Go to Step 4.
NO : Go to Step 5.
AC304988AB
Connector: B-17X
Front of
vehicle
1
3 2
4
Relay box side
AC304988AB
Connector: B-17X
Front of
vehicle
1
3 2
4
Relay box side
AC301541EU
Connector B-17X
(Relay box side)
Front of
vehicle1
3 2
4

TROUBLESHOOTING
HEATER, AIR CONDITIONER AND VENTILATION55-61
STEP 4. Check the wiring harness between B-17X
A/C compressor relay connector terminal No.2
and the ignition switch (IG2).
NOTE:
Prior to the wiring harness inspection, check
intermediate connector C-15, joint connector C-35,
junction block connectors C-209 and C-210, and
repair if necessary.
•Check the A/C compressor relay power supply
line for open circuit.
Q: Is the check result normal?
YES :
The trouble can be an intermittent
malfunction (Refer to GROUP 00, How to
Cope with Intermittent Malfunction P.00-5).
NO : Repair the wiring harness.
AC304988AB
Connector: B-17X
Front of
vehicle
1
3 2
4
Relay box side
AC303800
Connector: C-15

AE
C-15 (L)
AC303798
Connector: C-35

AJ
2 1313 12 1421 105 4616 15 17789
19 18 2011
22
C-35 (L)
AC303809
Connectors: C-209, C-210
AF
C-209
C-210
Junction block (front view)
C-209
Harness side
1016
145
12134117 238 9
C-210
Harness side
4 65321

TROUBLESHOOTING
HEATER, AIR CONDITIONER AND VENTILATION55-62
STEP 5. Check the wiring harness between B-17X
A/C compressor relay connector terminal No.2
and the ignition switch (IG2).
NOTE:
Prior to the wiring harness inspection, check
intermediate connector C-135, joint connector C-35,
junction block connectors C-209 and C-210, and
repair if necessary.
•Check the A/C compressor relay power supply
line for open circuit.
Q: Is the check result normal?
YES :
The trouble can be an intermittent
malfunction (Refer to GROUP 00, How to
Cope with Intermittent Malfunction P.00-5).
NO : Repair the wiring harness.
AC304988AB
Connector: B-17X
Front of
vehicle
1
3 2
4
Relay box side
AC303814
Connector: C-35

AI
C-35(L)
AC303818
Connector: C-135

AH
C-135 (L)
AC303823
Connectors: C-209, C-210
AE
C-210
Junction block (front view)
C-209
C-209
Harness side
1016
145
12134117 238 9
C-210
Harness side
4 65321

TROUBLESHOOTING
HEATER, AIR CONDITIONER AND VENTILATION55-63
STEP 6. Voltage measurement at B-17X A/C
compressor relay connector.
(1) Remove the relay, and measure at the junction
block side.
(2) Measure the voltage between terminal 1 and
body earth.
OK: System voltage
Q: Is the check result normal?
YES :
Go to Step 8.
NO : Go to Step 7.
STEP 7. Check the wiring harness between B-17X
A/C compressor relay connector terminal No.1
and the battery.
NOTE:
Prior to the wiring harness inspection, check
intermediate connector A-13 or C-111
, and repair if necessary.
•Check the A/C compressor relay power supply
line for open circuit.
Q: Is the check result normal?
YES :
The trouble can be an intermittent
malfunction (Refer to GROUP 00, How to
Cope with Intermittent Malfunction P.00-5).
NO : Repair the wiring harness.
AC304988AB
Connector: B-17X
Front of
vehicle
1
3 2
4
Relay box side
AC301541EV
Connector B-17X
(Relay box side)
Front of
vehicle1
3 2
4
AC304988AB
Connector: B-17X
Front of
vehicle
1
3 2
4
Relay box side
AC303857
Connector: A-13

AB
A-13 (B)
AC303816
Connector: C-111

AF
615
121179
810234