2005 MITSUBISHI LANCER air condition

TROUBLESHOOTING
HEATER, AIR CONDITIONER AND VENTILATION55-56
INSPECTION PROCEDURE 10: Malfunction of the A/C-ECU Power Supply System.
COMMENTS ON TROUBLE SYMPTOM
The A/C-ECU power system may be defective if the
air conditioner, defogger, and outside/inside air
selection damper motor all do not operate normally.
TROUBLESHOOTING HINTS
•Damaged the wiring harness or connectors
•Malfunction of the manual air conditioner control
panel (A/C-ECU)
IGNITION
SWITCH (IG2)
HEATER CONTROL PANELA/C-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
A/C-ECU Power Supply Circuit

TROUBLESHOOTING
HEATER, AIR CONDITIONER AND VENTILATION55-57
DIAGNOSIS
STEP 1. Connector check: C-139 A/C-ECU
connector
Q: Is the check result normal?
YES :
Go to Step 2.
NO : Repair the connector.
STEP 2. Voltage measurement at C-139 A/C-ECU
connector.
(1) Disconnect the connector, and measure at the
wiring harness side.
(2) Turn the ignition switch to the "ON" position.
(3) Measure the voltage between terminal 7 and
body earth.
OK: System voltage
Q: Is the check result normal?
YES :
Go to Step 4.
NO : Go to Step 3.
STEP 3. Check the wiring harness between C-139
A/C-ECU connector terminal No.7 and the
ignition switch (IG2).
NOTE:
Prior to the wiring harness inspection, check junction
block connectors C-210, C-212 and joint connector
C-35, and repair if necessary.
•Check the A/C-ECU power supply line for open
circuit.
AC303818
Connector: C-139

AJ
Harness side
C-139 (B)
11 12657 8 9 103 421
AC303818
Connector: C-139

AJ
Harness side
C-139 (B)
11 12657 8 9 103 421
AC301541ES
Connector C-139
(Harness side)
11 12
65
7 8 9 10
3 421
AC303818
Connector: C-139

AJ
Harness side
C-139 (B)
11 12657 8 9 103 421
AC303814
Connector: C-35

AS
C-35(L)
AC303823
Junction block (front view)
Connectors: C-210, C-212
C-210 Harness side
C-212
C-210
AJ

C-212
Harness side

TROUBLESHOOTING
HEATER, AIR CONDITIONER AND VENTILATION55-58
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.
STEP 4. Resistance measurement at the C-139
A/C-ECU connector.
(1) Disconnect the connector, and measure at the
wiring harness side.
(2) Measure the resistance between terminal 3 and
body earth.
OK: 2 ohms or less
Q: Is the check result normal?
YES :
Replace the manual air conditioner control
panel (A/C-ECU).
NO : Go to Step 5.
STEP 5. Check the wiring harness between C-139
A/C-ECU connector terminal No.3 and the earth.
•Check the A/C-ECU earth line for open circuit.
Q: Is the check result normal?
YES :
Replace the manual air conditioner control
panel (A/C-ECU).
NO : Repair the wiring harness.AC303818
Connector: C-139

AJ
Harness side
C-139 (B)
11 12657 8 9 103 421
AC301541ET
Connector C-139
(Harness side)
11 12657 8 9 103 421
AC303818
Connector: C-139

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

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