Infiniti P1442 Code: EVAP System Leak & Repair Guide

Understanding the Infiniti P1442 Diagnostic Trouble Code

When your Infiniti’s check engine light illuminates and you retrieve the OBD2 code P1442, you’re dealing with a specific issue within the vehicle’s Evaporative Emission Control (EVAP) system. This code is manufacturer-specific, meaning its definition can vary slightly between different Infiniti models, but it universally points to a problem in the EVAP canister system’s ability to control or detect fuel vapors. The EVAP system is a critical component for modern vehicles, designed to prevent fuel vapors from the gas tank from escaping into the atmosphere, thus reducing harmful hydrocarbon emissions.

What Does the P1442 Code Mean?

The generic definition for DTC P1442 is “Evaporative Emission Control System Leak Detected (Fuel Tank Pressure Control Solenoid Valve)”. In the context of Infiniti vehicles, this code typically indicates a malfunction related to the Canister Closed Valve (CCV) or the Purge Volume Control Valve (PVCV) system. The vehicle’s Engine Control Module (ECM) has detected an incorrect flow or pressure condition that suggests a leak, a blockage, or a faulty valve in the subsystem responsible for managing fuel vapor flow from the charcoal canister.

How the Infiniti EVAP System Works

To properly diagnose a P1442 code, a fundamental understanding of the EVAP system is essential. The system consists of several key components:

• Fuel Tank: Stores liquid fuel, which naturally produces vapors.
• Charcoal Canister: A container filled with activated charcoal that temporarily traps and stores fuel vapors.
• Canister Closed Valve (CCV) / Purge Volume Control Valve (PVCV): These valves control the flow of vapors from the canister to the engine intake to be burned during combustion.
• Fuel Tank Pressure Sensor: Monitors pressure/vacuum within the system.
• Vent Solenoid Valve: Allows the system to vent to the atmosphere or seal for leak tests.

The ECM performs periodic self-tests on this system. If it detects a flow rate or pressure that is outside the expected parameters when the CCV or PVCV is commanded open or closed, it will set the P1442 code.

Common Symptoms and Causes of P1442 in Infiniti

A P1442 code will trigger the illumination of the Malfunction Indicator Lamp (MIL), commonly known as the check engine light. While the vehicle may often drive normally, there are several symptoms and underlying causes that an Infiniti owner or technician should be aware of.

Primary Symptoms of a P1442 Code

• Check Engine Light: The most common and sometimes only symptom.
• Failed Emissions Test: Since the EVAP system controls emissions, a fault will cause an automatic test failure.
• Fuel Odor: In some cases, a noticeable smell of gasoline may be present if there is a physical leak.
• Slightly Reduced Fuel Economy: A faulty EVAP system can lead to inefficient fuel vapor management.

Root Causes of the P1442 Infiniti Code

Diagnosing the P1442 code requires a systematic approach, as the issue can stem from several sources. The most frequent causes include:

• Faulty Canister Closed Valve (CCV) or Purge Volume Control Valve (PVCV): The valve itself may be stuck open, stuck closed, or electrically defective.

Clogged or Cracked EVAP Canister: A clogged canister will restrict flow, while a cracked one will cause a leak.

• Damaged, Pinched, or Disconnected Hoses: The network of hoses connecting the EVAP components is vulnerable to damage, leading to leaks or blockages.
• Electrical Issues: Problems such as a damaged wiring harness, poor electrical connection, or blown fuse supplying the valve.
• Faulty Engine Control Module (ECM): This is rare, but a malfunctioning ECM can send incorrect signals.

Step-by-Step Diagnostic and Repair Procedure

Successfully resolving a P1442 code involves a logical diagnostic process. Always begin with a visual inspection before moving on to more complex electrical and functional tests. Ensure you have a professional-grade OBD2 scanner capable of reading live data and activating components.

Step 1: Preliminary Visual Inspection

Start with the simplest and most cost-effective checks. With the engine off, open the hood and locate the EVAP canister and associated valves (often near the firewall or behind the engine bay).

• Inspect all visible rubber hoses for cracks, brittleness, or disconnections.
• Check for any signs of physical damage to the charcoal canister, which is typically a black plastic box.
• Ensure all electrical connectors to the CCV/PVCV are securely plugged in and show no signs of corrosion.

Step 2: Functional Testing with a Scan Tool

Use your scan tool to command the CCV or PVCV on and off. You should hear a distinct clicking sound from the valve as it activates. If you do not hear a click, the valve may be faulty or not receiving power. Proceed to check for power and ground at the valve’s electrical connector with a digital multimeter (DMM).

Step 3: Checking for Vacuum and Restriction

This step requires a hand-held vacuum pump. Disconnect the hoses from the suspected faulty valve (CCV/PVCV).

• Apply vacuum to the valve’s ports according to the service manual diagram. A good valve should hold vacuum when de-energized and release it when commanded on with your scan tool.
• Check the hoses and the canister for restrictions by attempting to blow air through them. There should be minimal resistance.

Step 4: Smoke Testing for Leaks

If the valves and hoses check out, the most definitive test for leaks is a smoke test. A professional smoke machine introduces smoke into the EVAP system. Any leak, no matter how small, will allow smoke to escape, revealing the exact location of the problem. This is the most efficient way to find cracked hoses or a faulty canister.

Step 5: Clearing the Code and Verification

After making the necessary repairs (e.g., replacing a valve, repairing a hose), clear the DTCs with your scan tool. Then, drive the vehicle through a complete drive cycle to allow the ECM to run its self-tests again. If the repair was successful, the check engine light will not return, and the P1442 code will remain cleared.

Preventative Maintenance and Final Thoughts

While EVAP components don’t have a standard replacement interval, being mindful of your fuel filling habits can prolong their life. Avoid “topping off” your gas tank after the pump automatically shuts off, as this can force liquid fuel into the charcoal canister, damaging it and leading to codes like P1442. If you are not comfortable performing these diagnostics, it is highly recommended to seek a qualified technician, as the EVAP system is integral to your vehicle’s emissions compliance and overall performance.