Mitsubishi 380. Manual — part 206

AUTO A/C DIAGNOSIS

HEATER, AIR CONDITIONING AND VENTILATION

55-120

STEP 14. Check the wiring harness between choke coil
connector D-11 (terminal 1) and rear glass solder joint.
Q: Is the wiring harness between choke coil connector

D-11 (terminal 1) and rear glass solder joint in good
condition?
YES : Go to Step 15.
NO : Repair or replace the wiring harness. Refer to

GROUP 00E, Harness Connector Inspection

P.00E-2

. Check that the defogger system works

normally.

STEP 15. Check rear glass solder joints for loose,
corroded or damaged joints.

Q: Are solder joints in good condition?

YES : Go to Step 16.
NO : Repair solder joint. Check that the defogger system

works normally.

STEP 16. Check the wiring harness between RH rear glass
solder joint and earth point.
Q: Is the wiring harness between RH rear glass solder joint

and earth point in good condition?
YES : Go to Step 17.
NO : Repair or replace the wiring harness or repair solder

joint. . Check that the defogger system works
normally.

25DB152A

CONNECTORS: D-11

D-11

25DB154A

REAR GLASS SOLDER JOINTS:

.

.

AUTO A/C DIAGNOSIS

HEATER, AIR CONDITIONING AND VENTILATION

55-121

STEP 17. Check the defogger.
(1) Let the engine run at 2,000 r/min, and check the printed

heater with the battery fully charged.

(2) Turn on the defogger switch, and use a voltmeter to

measure the voltage in each printed heater at middle point
A on the rear window glass.

• The value should be approximately 6 volts.

Q: Does the defogger work normally?

YES : Replace the A/C-ECU. Check that the defogger

system works normally.

NO : Repair the defogger. Or replace rear glass. Refer to

GROUP 42, Rear Window Glass.

P.42-12

INSPECTION PROCEDURE 9: Defogger Timer Function does not Operate.

.

CIRCUIT OPERATION

Turn ON the defogger switch. If the defogger does
not shut off after about 16 minutes then the defogger
timer is malfunctioning.

.

TROUBLESHOOTING HINT

• Malfunction of the A/C-ECU

• Malfunction of the defogger timer

• Refer to component locations GROUP-

70

• Refer to configuration diagrams GROUP-

80

• Refer to circuit diagrams GROUP-

90

DIAGNOSIS

Replace the A/C-ECU.

12 V

6V

0V

12 V

6V

0V

AC100595

A

NORMAL CHARACTERISTIC CURVE

ABNORMAL CHARACTERISTIC CURVE

VOLTAGE

A (CENTER POINT)

APPROXIMATELY

6 V

NEGATIVE

TERMINAL

PRINTED

HEATER

LINE

POSITIVE

TERMINAL

NEGATIVE

TERMINAL

PRINTED

HEATER

LINE

POSITIVE

TERMINAL

OPENCIRCUIT

POINT

VOLTAGE

AB

AUTO A/C DIAGNOSIS

HEATER, AIR CONDITIONING AND VENTILATION

55-122

INSPECTION PROCEDURE 10: Malfunction of the A/C-ECU Power Supply System.

.

TECHNICAL DESCRIPTION (COMMENT)

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

• Malfunction of the A/C-ECU

• 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 A/C-ECU connector C-16 for loose,
corroded or damaged terminals, or terminals pushed back
in the connector.
Q: Is A/C-ECU connector C-16 in good condition?

YES : Go to Step 2.
NO : Repair or replace the connector. Refer to GROUP

00E, Harness Connector Inspection

P.00E-2

. Check

that the air conditioning works normally.

25DB107A

CONNECTOR: C-29

25DB068A

C-16 (B)

C-15 (B)

CONNECTORS: C-15, C-16

25DB094A

CONNECTORS: C-211, C-215

JUNCTION BLOCK

(FRONT VIEW)

C-215

C-211

25DB132A

HARNESS SIDE

C-16 (B)

21

22

23

24

25

26

27

28

29

30

31

32

33

34

35

36

CONNECTOR: C-16

AUTO A/C DIAGNOSIS

HEATER, AIR CONDITIONING AND VENTILATION

55-123

STEP 2. Measure the voltage at A/C-ECU connector C-16.
(1) Disconnect A/C-ECU connector C-16 and measure the

voltage at the harness side.

(2) Turn the ignition switch to the "ON" position.

(3) Measure the voltage between terminal 28 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 4.
NO : Go to Step 3.

STEP 3. Check the wiring harness between A/C-ECU
connector C-16 (terminal 28) and the ignition switch (IG2).

35DB032A

A-02 (GR)

CONNECTOR: A-02

HYDRAULIC UNIT

(WITH BUILT-IN ABS-ECU)

AC209365

21

22

23

24

25

26

27

28

29

30

31

32

33

34

35

36

CONNECTOR C-16
(HARNESS SIDE)

HK

25DB132A

HARNESS SIDE

C-16 (B)

21

22

23

24

25

26

27

28

29

30

31

32

33

34

35

36

CONNECTOR: C-16