Mitsubishi Lancer Evolution IX. Manual - part 311

TROUBLESHOOTING

REAR AXLE

27-19

STEP 7. Check the harness between direction 
valve (RH) connector F-23 terminal No.2 and 
4WD-ECU connector C-25 terminal No.14.

AC310740

1 2

Connector: F-23

F-23 (2-B)

AB

Hydraulic unit
assembly

AC310721

18

16

1415

17

23

21

1920

22

26

2425

3

1 2

4 5

10

8

6 7

9

13

12

11

4WD-ECU

C-25 (26-Y)

Connector: C-25

AB

Check the output line for short-circuited or open cir-
cuit.

Q: Is the check result normal?

YES : 

Replace the 4WD-ECU.

NO : 

Repair the wiring harness.

Code No.73: Direction valve (LH) system

DIRECTION VALVE (LH) SYSTEM 
CIRCUIT

 Refer to 

P.27-11

.

OPERATION

• After processing information of various sensors 

and switches, the 4WD-ECU calculates the 
amount of AYC torque movement and direction, 
and controls the direction valve (LH).

• The current flows from the 4WD-ECU to activate 

the direction valve (LH), which supplies the oil 
pressure to the AYC left clutch.

DIAGNOSIS CODE SET CONDITIONS

Diagnosis code No.73 is set when the direction valve 
(LH) control circuit is open circuited or 
short-circuited.

PROBABLE CAUSES

• Malfunction of the direction valve (LH)

• Damaged harness wires and connectors

• Malfunction of the 4WD-ECU

TROUBLESHOOTING

REAR AXLE

27-20

DIAGNOSIS

STEP 1. M.U.T.-II/III data list
Set M.U.T.-II/III to data reading mode, and check the 
data list item.
Item 60: direction valve (LH) (Refer to Data List Table 

P.22A-142

). 

Q: Is the check result normal?

YES : 

This malfunction is intermittent. Refer to 

GROUP 00, How to Use 
Troubleshooting/Inspection Service Points 

− 

How to Cope with Intermittent Malfunction 

P.00-5

.

NO : 

Go to Step 2.

STEP 2. Measure the resistance at direction valve 
(LH) connector F-22.

AC310739

1 2

Connector: F-22

F-22 (2-B)

AB

Hydraulic unit
assembly

Disconnect the connector, and measure the resist-
ance between terminal 1 and 2 at the direction valve 
(LH) side.

OK: 19 

− 21 Ω or less

Q: Is the check result normal?

YES : 

Go to Step 3.

NO : 

Replace the hydraulic unit.

STEP 3. Measure the resistance at direction valve 
(LH) connector F-22.

AC310739

1 2

Connector: F-22

F-22 (2-B)

AB

Hydraulic unit
assembly

Measure the resistance between terminal 1 and 
earth at the direction valve (LH) side

OK: 2 

Ω or less

Q: Is the check result normal?

YES : 

Go to Step 4.

NO : 

Repair the defective connector.

STEP 4. Connectors check: F-22 direction valve 
(LH) connector, F-21 intermediate connector

AC310739

1 2

Connector: F-22

F-22 (2-B)

AB

Hydraulic unit
assembly

7

3

5

1

6

2

8

4

AC310719AB

Connector: F21

F-21 (8-B)

Check for the contact with terminals.

Q: Is the check result normal?

YES : 

Go to Step 5.

NO : 

Repair the defective connector.

TROUBLESHOOTING

REAR AXLE

27-21

STEP 5. Check the harness wires between 
direction valve (LH) connector F-22 terminal 1 
and intermediate connector F-21 and body earth.

AC310739

1 2

Connector: F-22

F-22 (2-B)

AB

Hydraulic unit
assembly

7

3

5

1

6

2

8

4

AC310719AB

Connector: F21

F-21 (8-B)

Check the earth line for open circuit.

Q: Is the check result normal?

YES : 

Go to Step 6.

NO : 

Repair the wiring harness.

TROUBLESHOOTING

REAR AXLE

27-22

STEP 6. Connectors check: C-25 4WD-ECU 
connector, C-122, C-134 and F-21 intermediate 
connectors, and F-22 direction valve (LH) 
connector

AC310721

18

16

1415

17

23

21

1920

22

26

2425

3

1 2

4 5

10

8

6 7

9

13

12

11

4WD-ECU

C-25 (26-Y)

Connector: C-25

AB

AC310724

2

1

3

13

12

14

21

10

5

4

6

16

15

17

7 8 9

19

18

20

11

22

Connector: C-122
<LHD>

AB

C-122 
(22-L)

AC310725

2

1

3

13

12

14

21

10

5

4

6

16

15

17

7 8 9

19

18

20

11

22

Connector: C-122
<RHD>

AB

C-122 (22-L)

AC310723

6

2

5

1

7 8

11

4

9 10

3

Connector: C-134
<LHD>

AB

C-134 (11-B)

AC310726

6

2

5

1

7 8

11

4

9 10

3

Connector: C-134
<RHD>

AB

C-134 (11-B)

7

3

5

1

6

2

8

4

AC310719AB

Connector: F21

F-21 (8-B)

AC310739

1 2

Connector: F-22

F-22 (2-B)

AB

Hydraulic unit
assembly

Check for the contact with terminals.

Q: Is the check result normal?

YES : 

Go to Step 7.

NO : 

Repair the defective connector.