The Nissan P1491 code is an error code that is associated with the vehicle’s EVAP Vacuum Cut Valve/Bypass Circuit. When the engine is running at normal operating temperature, the PCM (Powertrain Control Module) detects an open or shorted condition in the Vacuum Vent Cut Valve/Bypass valve circuit. This issue can be caused by a variety of factors such as damage to the EVAP vacuum cut bypass valve, the EVAP vacuum cut valve, the EVAP control system pressure sensor, a blocked or bent vapor hose between the fuel tank and the cut valve, or a clogged or damaged canister purge valve. It is important to understand the causes and solutions of the Nissan P1491 code in order to properly repair the issue and prevent further damage to the vehicle.
Causes and Solutions of the Nissan P1491 Code
| Cause | Solution |
|---|---|
| EVAP vacuum cut bypass valve is damaged or has failed | Replace the valve with a new one |
| EVAP vacuum cut valve is damaged or has failed | Replace the valve with a new one |
| EVAP control system pressure sensor damaged or has failed | Replace the sensor with a new one |
| Vapor hose between fuel tank and cut valve is blocked or bent | Clean and straighten the hose |
| Clogged or damaged canister purge valve | Replace the valve with a new one |
Understanding the Nissan P1491 code is essential for vehicle owners, as it is an indication that a problem has arisen with the EVAP Vacuum Cut Valve/Bypass Circuit. This code is associated with the Powertrain Control Module (PCM) detecting an open or shorted condition in the circuit, which can be caused by a variety of factors. It is important to be aware of the causes and solutions of the Nissan P1491 code in order to properly repair the issue and prevent further damage to the vehicle.
EVAP Vacuum Cut Bypass Valve
When the engine is running at normal operating temperature, the PCM will detect an open or shorted condition in the EVAP Vacuum Cut Bypass Valve/Bypass Circuit. This can be caused by a damaged or failed EVAP Vacuum Cut Bypass Valve. To repair this issue, the valve must be replaced with a new one.
EVAP Vacuum Cut Valve
Another possible cause of the Nissan P1491 code is a damaged or failed EVAP Vacuum Cut Valve. This valve is responsible for controlling the flow of the vapor from the fuel tank to the EVAP system. To repair this issue, the valve must be replaced with a new one.
EVAP Control System Pressure Sensor
The EVAP Control System Pressure Sensor monitors the pressure of the vapor in the EVAP system. If the sensor is damaged or has failed, it can cause the Nissan P1491 code. To repair this issue, the sensor must be replaced with a new one.
Vapor Hose Between Fuel Tank and Cut Valve
Another possible cause of the Nissan P1491 code is a blocked or bent vapor hose between the fuel tank and the cut valve. To repair this issue, the hose must be cleaned and straightened.
Clogged or Damaged Canister Purge Valve
The final possible cause of the Nissan P1491 code is a clogged or damaged canister purge valve. This valve is responsible for controlling the flow of the vapor from the fuel tank to the EVAP system. To repair this issue, the valve must be replaced with a new one.
Conclusion
The Nissan P1491 code is an indication that a problem has arisen with the EVAP Vacuum Cut Valve/Bypass Circuit. There are five possible causes of this code, and it is important to be aware of the causes and solutions in order to properly repair the issue and avoid further damage to the vehicle. By understanding the Nissan P1491 code and taking the appropriate steps to repair the issue, vehicle owners can ensure that their vehicle’s EVAP system is functioning properly.
https://www.youtube.com/watch?v=HU6PeVZOUCs