Vacuum Cut Valve Bypass Valve
Table of contents
- Possible Causes
- How To Fix
- Tech Notes
- Cost To Diagnose
- When is the code detected
- Possible Symptoms
- Description
P1490 NISSAN Possible Causes
- Faulty Vacuum Cut Valve Bypass Valve
- Clogged vacuum hoses to the Vacuum Cut Valve Bypass Valve
- Vacuum cut valve bypass valve harness is open or shorted
- Vacuum cut valve bypass valve electrical circuit poor connection
How do I fix code P1490 NISSAN?
Check the “Possible Causes” listed above. Visually inspect the related wiring harness and connectors. Check for damaged components and look for broken, bent, pushed out, or corroded connector’s pins.
Tech Notes
- There is a factory service bulletin for the following Nissan models:
- 2002 Nissan Altima
- 2003 Nissan Altima
- 2004 Nissan Altima
- 2005 Nissan Altima
- 2002-2005 Nissan Altima Service Bulletin OBDII Code P1490
Cost of diagnosing the P1490 NISSAN code
The cost of diagnosing the P1490 NISSAN code is 1.0 hour of labor. The auto repair labor rates vary by location, your vehicle’s make and model, and even your engine type. Most auto repairs shops charge between $75 and $150 per hour.
When is the code detected
An improper voltage signal is sent to ECM through vacuum cut valve bypass valve.
Possible Symptoms
- Engine Light ON (or Service Engine Soon Warning Light)
P1490 NISSAN Description
The vacuum cut valve and vacuum cut valve bypass valve are installed in parallel on the EVAP purge line between the fuel tank and the EVAP canister.
The vacuum cut valve prevents the intake manifold vacuum from being applied to the fuel tank. The vacuum cut valve bypass valve is a solenoid type valve and generally remains closed. It opens only for on board diagnosis.
The vacuum cut valve bypass valve responds to signals from the Engine Control Module (ECM). When the ECM sends an ON (ground) signal, the valve is opened. The vacuum cut valve is then bypassed to apply intake manifold vacuum to the fuel tank.