AutoCodes – Infiniti – P1440 Infiniti

P1440 Infiniti Code - Evaporative Emission Control System Small Leak

Quick Answer

This diagnosis detects leaks in the Evaporative Emission (EVAP) purge line using vapor pressure in the fuel tank. Common causes include Fuel filler cap remains open or fails to close, Foreign matter caught in fuel filler cap, Incorrect fuel tank vacuum relief valve. 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: P1440 Infiniti indicates Evaporative Emission Control System Small Leak.
Common causes: Common causes include Fuel filler cap remains open or fails to close, Foreign matter caught in fuel filler cap, Incorrect fuel tank vacuum relief valve.
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 19,508

How popular is this code, among other codes? Low

Repair Importance Level

Urgent (Diagnose now) (3 / 3)

Repair Difficulty Level

Advanced (Pro) (3 / 3)

What is this?

Table of contents Created and updated by William Orellana on Jun 30, 2020

Description
Possible Causes
How To Fix
Tech Notes
Cost to Diagnose
FAQs
Comments
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Code P1440 Infiniti Description

This diagnosis detects leaks in the Evaporative Emission (EVAP) purge line using vapor pressure in the fuel tank. The EVAP canister vent control valve is closed to shut the EVAP purge line. The vacuum cut valve bypass valve will then be opened to clear the line between the fuel tank and the EVAP canister purge volume control solenoid valve. The EVAP control system pressure sensor can now monitor the pressure inside the fuel tank. If pressure increases, the Engine Control Module (ECM) will check for leaks in the line between the vacuum cut valve and EVAP canister purge volume control solenoid valve.

OBDII Code P1440 Infiniti - Evaporative Emission Control System Small Leak - AutoCodes.com — P1440 Infiniti Code - Evaporative Emission Control System Small Leak

What does this mean?

What are the Possible Causes of the DTC P1440 Infiniti?

Fuel filler cap remains open or fails to close
Foreign matter caught in fuel filler cap
Incorrect fuel tank vacuum relief valve
Incorrect fuel filler cap used
Leak is in line between intake manifold and EVAP canister purge volume control solenoid valve
Foreign matter caught in EVAP canister vent control valve
EVAP canister or fuel tank leaks
EVAP purge line (pipe and rubber tube) leaks
EVAP purge line rubber tube bent
Blocked or bent rubber tube to EVAP control system pressure sensor
Loose or disconnected rubber tube
EVAP canister vent control valve and the circuit
O-ring of EVAP canister vent control valve is missing or damaged
EVAP canister is saturated with water
EVAP control system pressure sensor
Absolute pressure sensor

How to Fix the DTC P1440 Infiniti?

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 does this mean?

Code Tech Notes

The most common cause for the P1440 code is a loose or missing fuel filler cap. Resecure or install the cap and reset the engine light. In some cases, the light will turn off by itself after a few days of driving the vehicle. if the problem persists replaced the gas cap.

There is an Infiniti Service Bulletin to help diagnose the P1440 code:
Infiniti Factory Service Bulletin OBDII Code P1440

What is the Cost to Diagnose the Code?

Labor: 1.0

To diagnose the P1440 Infiniti 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.

Need more information about the P1440 Infiniti code?

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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.

Frequently Asked Questions about P1440 Infiniti Code

1. What are the common symptoms of an OBDII code P1440 in an Infiniti related to the Evaporative Emission Control System Small Leak?

- Common symptoms include the illumination of the check engine light, a noticeable fuel odor around the vehicle, and potential issues with the vehicle's emissions system.

2. What are the possible causes of an OBDII code P1440 in an Infiniti?

- The code P1440 in an Infiniti is often caused by a loose or damaged gas cap, a leak in the evaporative emission system, a faulty purge control valve, or a problem with the charcoal canister.

3. How can I diagnose the source of an Evaporative Emission Control System Small Leak in my Infiniti triggering the P1440 code?

- To diagnose the issue, you can start by checking the gas cap for proper sealing, inspecting the evaporative emission system components for visible damage or leaks, and using a smoke machine to identify the source of the leak.

4. Can a loose gas cap trigger the OBDII code P1440 in an Infiniti?

- Yes, a loose or improperly tightened gas cap can create a small leak in the evaporative emission control system, leading to the triggering of the P1440 trouble code.

5. What are some repair tips for addressing an OBDII code P1440 related to the Evaporative Emission Control System Small Leak in an Infiniti?

- Repair tips include ensuring the gas cap is tightened properly, inspecting and replacing damaged hoses or components in the evaporative emission system, testing and potentially replacing the purge control valve, and checking the charcoal canister for any issues.

6. Is it safe to continue driving an Infiniti with an OBDII code P1440 related to the Evaporative Emission Control System Small Leak?

- While the vehicle may still be operational with this code, it is important to address the issue promptly to prevent potential damage to the emissions system and ensure the vehicle meets regulatory standards.

7. How much does it typically cost to repair an OBDII code P1440 in an Infiniti caused by an Evaporative Emission Control System Small Leak?

- The cost of repairs can vary depending on the exact cause of the code, but it may range from around $100 for a simple fix like a gas cap replacement to several hundred dollars for more complex repairs involving components like the charcoal canister or purge valve.

8. Can I reset the OBDII code P1440 in my Infiniti after making repairs to the Evaporative Emission Control System?

- Yes, once the issue causing the code has been addressed, you can reset the code using an OBDII scanner or by disconnecting the vehicle's battery for a few minutes to clear the stored error code.

9. How long does it typically take to repair an OBDII code P1440 related to the Evaporative Emission Control System Small Leak in an Infiniti?

- The repair time can vary depending on the specific cause of the issue and the complexity of the repair needed, but most repairs for this code can be completed within a few hours to a day at a qualified repair shop.

10. Are there any preventative maintenance steps I can take to avoid triggering the OBDII code P1440 in my Infiniti in the future?

- Regularly checking and properly tightening the gas cap, conducting routine inspections of the evaporative emission system components, and following the manufacturer's recommended maintenance schedule can help prevent the recurrence of the P1440 trouble code.