2005 MITSUBISHI 380 Workshop Manual

AUTO A/C DIAGNOSIS
HEATER, AIR CONDITIONING AND VENTILATION55-108
STEP 5. Check A/C-ECU C-15 and C-16 for loose, corroded
or damaged terminals, or terminals pushed back in the
connector.
Q: Are A/C-ECU C-15 and C-16 in good condition?
YES : Go to Step 6.
NO : Repair or replace the connector. Refer to GROUP
00E, Harness Connector Inspection P.00E-2. Check
that the air conditioning works normally.

AUTO A/C DIAGNOSIS
HEATER, AIR CONDITIONING AND VENTILATION55-109
STEP 6. Check the wiring harness between A/C-ECU
connector C-15 (terminal 12), C-16 (terminals 34 and 26)
and A/C pressure sensor connector A-30 (terminals 3, 1
and 2).
Q: Is the wiring harness between A/C-ECU connector C-15
(terminal 12), C-16 (terminals 34 and 26) and A/C
pressure sensor connector A-30 (terminals 3, 1 and 2) in
good condition?
YES : Repair the A/C-ECU. Check that the air conditioning
works normally.
NO : Repair the wiring harness. Check that the air
conditioning works normally.
STEP 7. Check the refrigerant level.
Use the refrigerant recovery station to remove all of the refrig-
erant, and then calculate the amount of the refrigerant and
charge it.
Q: Is the refrigerant level correct?
YES : Replace the A/C-ECU.Check that the air conditioning
works normally.
NO : Correct the refrigerant level (Refer to On-vehicle
ServiceP.55-144). Check that the air conditioning
works normally.

AUTO A/C DIAGNOSIS
HEATER, AIR CONDITIONING AND VENTILATION55-110
INSPECTION PROCEDURE 8: Defogger Function Does Not Operate.
.
TECHNICAL DESCRIPTION (COMMENT)
If the defogger does not operate when the defogger
switch is turned on, the defogger relay system may
be defective.
.
TROUBLESHOOTING HINTS
Malfunction of the A/C-ECU
Malfunction of the defogger relay
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 the A/C and outside/inside air selection
damper control motor operation.
Q: Do the A/C 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 systemP.55-122."

AUTO A/C DIAGNOSIS
HEATER, AIR CONDITIONING AND VENTILATION55-111
STEP 2. Check defogger relay connector C-201 for loose,
corroded or damaged terminals, or terminals pushed back
in the connector.
Q: Is defogger relay connector C-201 in good condition?
YES : Go to Step 3.
NO : Repair or replace the connector. Refer to GROUP
00E, Harness Connector Inspection P.00E-2. The
defogger system should work normally.
STEP 3. Check the defogger relay continuity.
Follow the table below to check the defogger relay for continu-
ity.
Q: Is the defogger relay in good condition?
YES : Go to Step 4.
NO : Replace the defogger relay. The defogger system
should work normally.
BATTERY VOLTAGE CONNECT
TESTER
BETWEENSPECIFIED
CONDITION
Not applied 4
5 Open Circuit
Connect terminal 1
to the positive
battery terminal
Connect terminal 3
to the negative
battery terminal4
5 Less than 2 ohms

AUTO A/C DIAGNOSIS
HEATER, AIR CONDITIONING AND VENTILATION55-112
STEP 4. Check choke coil connector D-11 for loose,
corroded or damaged terminals, or terminals pushed back
in the connector.
Q: Is choke coil connector D-11 in good condition?
YES : Go to Step 5.
NO : Repair or replace the connector. Refer to GROUP
00E, Harness Connector Inspection P.00E-2. The
defogger system should work normally.

AUTO A/C DIAGNOSIS
HEATER, AIR CONDITIONING AND VENTILATION55-113
STEP 5.Measure the voltage at choke coil connector D-11.
(1) Disconnect connector D-11, and measure the voltage at the
harness side.
(2) Disconnect A/C-ECU connector C-15 and ground harness
side terminal No.27.
(3) Turn the ignition switch to the "ON" position.
(4) Measure the voltage between choke coil connector D-11
terminal No.1 and ground.
The measured value should be approximately 12 volts.
Q: Is the measured voltage approx. 12 volts?
YES : Go to Step 13.
NO : Go to Step 6.

AUTO A/C DIAGNOSIS
HEATER, AIR CONDITIONING AND VENTILATION55-114
STEP 6. Measure the voltage at defogger relay connector
C-201.
(1) Disconnect defogger relay connector C-201, and measure
the voltage at the junction block side.
(2) Measure the voltage between terminal 5 and ground.
The measured value should be approximately 12 volts
(battery positive voltage).
Q: Is the measured voltage approx. 12 volts?
YES : Go to Step 8.
NO : Go to Step 7.

AUTO A/C DIAGNOSIS
HEATER, AIR CONDITIONING AND VENTILATION55-115
STEP 7. Check the wiring harness between defogger relay
connector C-201 (terminal 5) and the fusible link (1).
NOTE: Also check intermediate connector C-31 and junction
block connector C-216 for loose, corroded, or damaged termi-
nals, or terminals pushed back in the connector. If intermediate
connector C-31 and junction block connector C-216 is dam-
aged, repair or replace the connector as described in GROUP
00E, Harness Connector Inspection P.00E-2.
Q: Is the wiring harness between defogger relay connector
C-201(terminal 5) and the fusible link (1) in good
condition?
YES : It can be assumed that this malfunction is intermittent.
Refer to GROUP 00, How to Use
Troubleshooting/Inspection Service Points
How to
Cope with Intermittent Malfunctions P.00-14.
NO : Repair the wiring harness. Check that the defogger
system works normally.