Infiniti M45 (Y34). Manual - part 476

DTC P1491 VACUUM CUT VALVE BYPASS VALVE

EC-593

C

D

E

F

G

H

I

J

K

L

M

A

EC

Overall Function Check

ABS002RT

Use this procedure to check the overall function of vacuum cut valve bypass valve. During this check, the 1st
trip DTC might not be confirmed.

 WITH GST

1.

Remove vacuum cut valve and vacuum cut valve bypass valve as an assembly.

2.

Apply vacuum to port A  and check that there is no suction from
port B .

3.

Apply vacuum to port B  and check that there is suction from
port A .

4.

Blow air in port B  and check that there is a resistance to flow out
of port A .

5.

Supply battery voltage to the terminal.

6.

Blow air in port A  and check that air flows freely out of port B .

7.

Blow air in port B  and check that air flows freely out of port A .

8.

If NG, go to “

EC-595, "Diagnostic Procedure"

 .

SEF530Q

EC-594

DTC P1491 VACUUM CUT VALVE BYPASS VALVE

Wiring Diagram

ABS002RU

TBWA0310E

DTC P1491 VACUUM CUT VALVE BYPASS VALVE

EC-595

C

D

E

F

G

H

I

J

K

L

M

A

EC

Specification data are reference values and are measured between each terminal and ground.

CAUTION:

Do not use ECM ground terminals when measuring input/output voltage. Doing so may result in dam-
age to the ECM's transistor. Use a ground other than ECM terminals, such as the ground.

Diagnostic Procedure

ABS002RV

1. 

INSPECTION START

Do you have CONSULT-II?
Yes or No

Yes

>> GO TO 2.

No

>> GO TO 3.

2. 

CHECK VACUUM CUT VALVE BYPASS VALVE OPERATION

 With CONSULT-II

1.

Turn ignition switch OFF.

2.

Remove vacuum cut valve and vacuum cut valve bypass valve as an assembly.

3.

Apply vacuum to port A and check that there is no suction from port B.

4.

Apply vacuum to port B and check that there is suction from port A.

5.

Blow air in port B and check that there is a resistance to flow out of port A.

6.

Turn ignition switch ON.

7.

Select “VC/V BYPASS/V” in “ACTIVE TEST” mode with CONSULT-II and touch “ON”.

8.

Blow air in port A and check that air flows freely out of port B.

9.

Blow air in port B and check that air flows freely out of port A.

OK or NG

OK

>> GO TO 4.

NG

>> GO TO 5.

TER-

MINAL 

NO.

WIRE 

COLOR

ITEM

CONDITION

DATA (DC Voltage)

43

G/Y

Vacuum cut valve 
bypass valve

[Ignition switch: ON]

BATTERY VOLTAGE
(11 - 14V)

PBIB0161E

EC-596

DTC P1491 VACUUM CUT VALVE BYPASS VALVE

3. 

CHECK VACUUM CUT VALVE BYPASS VALVE OPERATION

 Without CONSULT-II

1.

Turn ignition switch OFF.

2.

Remove vacuum cut valve and vacuum cut valve bypass valve as an assembly.

3.

Apply vacuum to port A and check that there is no suction from port B.

4.

Apply vacuum to port B and check that there is suction from port A.

5.

Blow air in port B and check that there is a resistance to flow out of port A.

6.

Disconnect vacuum cut valve bypass valve harness connector.

7.

Supply battery voltage to the terminal.

8.

Blow air in port A and check that air flows freely out of port B.

9.

Blow air in port B and check that air flows freely out of port A.

OK or NG

OK

>> GO TO 4.

NG

>> GO TO 7.

4. 

CHECK EVAP PURGE LINE

Check EVAP purge line between EVAP canister and fuel tank for clogging or disconnection.
OK or NG

OK

>> GO TO 5.

NG

>> Repair it.

5. 

CHECK EVAP PURGE PORT

Check EVAP purge port of fuel tank for clogging.
OK or NG

OK

>> GO TO 6.

NG

>> Clean EVAP purge port.

6. 

CHECK EVAP CANISTER

1.

Pinch the fresh air hose.

2.

Blow air into port A  and check that it flows freely out of port B .

OK or NG

OK

>> GO TO 12.

NG

>> Replace EVAP canister.

PBIB0635E

AEC630A