2005 MITSUBISHI LANCER Workshop Manual

TROUBLESHOOTING
HEATER, AIR CONDITIONER AND VENTILATION55-53
INSPECTION PROCEDURE 9: 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)
A/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 HEATER CONTROL PANEL
A/C-ECU Power Supply Circuit

TROUBLESHOOTING
HEATER, AIR CONDITIONER AND VENTILATION55-54
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 the voltage 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 10 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.10 and the
ignition switch (IG2).
NOTE:
Prior to the wiring harness inspection, check junction
block connectors C-210 and C-212, and repair if
necessary.
•Check the A/C-ECU 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.
AC303802
Connector: C-139

AE
C-139 (B)
Harness side
AC303802
Connector: C-139

AE
C-139 (B)
Harness side
AC301541EQ
Connector C-139
(Harness side)
9
1
1574
12
1110
23
13
5
14616
8
AC303802
Connector: C-139

AE
C-139 (B)
Harness side
AC303809
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 VENTILATION55-55
STEP 4. Resistance measurement resistance at
C-139 A/C-ECU connector.
(1) Disconnect the connector, and measure at the
wiring harness side.
(2) Measure the resistance between terminal 12 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.12 and the earth.
NOTE:
Prior to the wiring harness inspection, check joint
connector C-104, and repair if necessary.
•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.
AC303802
Connector: C-139

AE
C-139 (B)
Harness side
AC301541ER
Connector C-139
(Harness side)
91
1574
12111023135146168
AC303802
Connector: C-139

AE
C-139 (B)
Harness side
AC303804
Connector: C-104

AJ
C-104 (GR)

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