AutoCodes – Nissan – P1801 Nissan

P1801 Nissan Code - Variable Intake Air System Control Solenoid Valve 2

Quick Answer

When the engine is running at low or medium speed, the power valve is fully closed. Common causes include Faulty VIAS control solenoid valve 2, VIAS control solenoid valve circuit harness is open or shorted, VIAS control solenoid valve circuit poor electrical connection. Severity is High - diagnose this code as soon as possible. Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.

What it means: P1801 Nissan indicates Variable Intake Air System Control Solenoid Valve 2.
Common causes: Common causes include Faulty VIAS control solenoid valve 2, VIAS control solenoid valve circuit harness is open or shorted, VIAS control solenoid valve circuit poor electrical connection.
Severity: High - diagnose this code as soon as possible.
Can I drive?: Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.

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Code Popularity 29,688

How popular is this code, among other codes? Low

Repair Importance Level

Urgent (Diagnose now) (3 / 3)

Repair Difficulty Level

Intermediate (2 / 3)

What is this?

Table of contents Created and updated by William Orellana on Sep 20, 2019

Description
Possible Causes
How To Fix
Cost to Diagnose
Comments
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Code P1801 Nissan Description

When the engine is running at low or medium speed, the power valve is fully closed. Under this condition, the effective suction port length is equivalent to the total length of the intake manifold collector's suction port including the intake valve. This long suction port provides increased air intake which results in improved suction efficiency and higher torque generation.
The surge tank and one-way valve are provided. When the engine is running at high speed, the Engine Control Module (ECM) sends the signal to the Variable Intake Air System (VIAS) control solenoid valve. This signal introduces the intake manifold vacuum into the power valve actuator and therefore opens the power valve to two suction passages together in the collector.
Under this condition, the effective port length is equivalent to the length of the suction port provided independently for each cylinder. This shortened port length results in enhanced engine output with reduced suction resistance under high speeds.

OBDII Code P1801 Nissan - Variable Intake Air System Control Solenoid Valve 2 - AutoCodes.com — P1801 Nissan Code - Variable Intake Air System Control Solenoid Valve 2

What does this mean?

What are the Possible Causes of the DTC P1801 Nissan?

Faulty VIAS control solenoid valve 2
VIAS control solenoid valve circuit harness is open or shorted
VIAS control solenoid valve circuit poor electrical connection

How to Fix the DTC P1801 Nissan?

Review the 'Possible Causes' above and visually examine the corresponding wiring harness and connectors. Check for damaged components and inspect connector pins for signs of being broken, bent, pushed out, or corroded.

What is the Cost to Diagnose the Code?

Labor: 1.0

To diagnose the P1801 Nissan code, it typically requires 1.0 hour of labor. Rates vary by location, vehicle, and shop. Many shops charge between $80–$150 per hour; dealerships and metro areas may be higher, independents may be lower.

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Information for Specific Nissan Models

P1801 2008 Nissan Altima Sedan — Variable Intake Air System Control Solenoid Valve 2
P1801 2009 Nissan Altima Sedan — Variable Intake Air System Control Solenoid Valve 2
P1801 2010 Nissan Altima Sedan — Variable Intake Air System Control Solenoid Valve 2
P1801 2011 Nissan Altima Sedan — Variable Intake Air System Control Solenoid Valve 2
P1801 2012 Nissan Altima Sedan — Variable Intake Air System Control Solenoid Valve 2

About the author: William Orellana is a Master Mechanic and Mechanical Engineer with over 30 years of experience diagnosing and repairing vehicles. Learn more about his background.