Nissan Frontier D22. Manual - part 350

DTC P1490 VACUUM CUT VALVE BYPASS VALVE

EC-503

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Wiring Diagram

UBS00DC5

BBWA1067E

EC-504

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DTC P1490 VACUUM CUT VALVE BYPASS VALVE

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

UBS00DC6

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 CIRCUIT

1.

Turn ignition switch ON.

2.

Perform “VC/V BYPASS/V” in “ACTIVE TEST” mode.

3.

Make sure that clicking sound is heard from the vacuum cut
valve bypass valve.

OK or NG

OK

>> GO TO 7.

NG

>> GO TO 3.

TER-

MINAL 

NO.

WIRE 

COLO

R

ITEM

CONDITION

DATA (DC Voltage)

120

P/B

Vacuum cut valve bypass 
valve

[Ignition switch: ON]

BATTERY VOLTAGE
(11 - 14V)

SEF806Y

DTC P1490 VACUUM CUT VALVE BYPASS VALVE

EC-505

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3. 

CHECK POWER SUPPLY

1.

Turn ignition switch OFF.

2.

Disconnect vacuum cut valve bypass valve harness connector.

3.

Turn ignition switch ON.

4.

Check voltage between terminal 2 and ground with CONSULT-II
or tester.

OK or NG

OK

>> GO TO 5.

NG

>> GO TO 4.

4. 

DETECT MALFUNCTIONING PART

Check the following.

●

Harness connectors E43, M65

●

Harness connectors M67, C1

●

Fuse block (J/B) connector E49

●

10A fuse

●

Harness for open or short between vacuum cut valve bypass valve and fuse

>> Repair harness or connectors.

5. 

CHECK OUTPUT SIGNAL CIRCUIT

1.

Turn ignition switch OFF.

2.

 Disconnect ECM harness connector.

3.

Check harness continuity between ECM terminal 120 and vacuum cut valve bypass valve terminal 1.
Refer to Wiring Diagram.

4.

Also check harness for short to ground and short to power.

OK or NG

OK

>> GO TO 7.

NG

>> GO TO 6.

SEF186S

Voltage

: Battery voltage

SEF192V

Continuity should exist.

EC-506

[KA24DE]

DTC P1490 VACUUM CUT VALVE BYPASS VALVE

6. 

DETECT MALFUNCTIONING PART

Check the following.

●

Harness connectors M67, C1

●

Harness connectors M81, F36

●

Harness for open or short between vacuum cut valve bypass valve and ECM

>> Repair open circuit or short to ground or short to power in harness or connectors.

7. 

CHECK VACUUM CUT VALVE BYPASS VALVE

 With CONSULT-II

Check air passage continuity.
Perform “VC/V BYPASS/V” in “ACTIVE TEST” mode.

 Without CONSULT-II

Check air passage continuity shown in the figure.

OK or NG

OK

>> GO TO 8.

NG

>> Replace vacuum cut valve bypass valve.

8. 

CHECK INTERMITTENT INCIDENT

Perform 

EC-120, "TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT"

 .

>> INSPECTION END

SEF807Y

SEF557Y