AutoCodes – Nissan – P1421 2009 Nissan Sentra

P1421 2009 Nissan Sentra Code - Cold Start Control

Quick Answer

The Engine Control Module (ECM) controls ignition timing and engine idle speed when the engine is started with pre-warming up condition. Common causes include Lack of intake air volume (block air filter), Fuel injection system (Clogged fuel injector or bad fuel pump), Faulty Engine Control Module (ECM). 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: P1421 2009 Nissan Sentra indicates Cold Start Control.
Common causes: Common causes include Lack of intake air volume (block air filter), Fuel injection system (Clogged fuel injector or bad fuel pump), Faulty Engine Control Module (ECM).
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.

Save to My Repairs My Repairs

AI answers can be wrong. Verify repairs with testing. Open full chat

Code Popularity 5,941

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 Oct 07, 2022

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
Add Comment

💬 Need more help? Ask Coddy for instant answers — it's free!

Code P1421 2009 Nissan Sentra Description

The Engine Control Module (ECM) controls ignition timing and engine idle speed when the engine is started with pre-warming up condition. This control promotes the activation of three-way catalyst by heating the catalyst and reduces emissions. The Diagnostic Trouble Code (DTC) will be set when the ECM does not control ignition timing and engine speed properly when the engine is started with prewarming up condition.

OBDII Code P1421 2009 Nissan Sentra - Cold Start Control - AutoCodes.com — P1421 2009 Nissan Sentra Code - Cold Start Control

What does this mean?

What are the Possible Causes of the DTC P1421 2009 Nissan Sentra?

Lack of intake air volume (block air filter)
Fuel injection system (Clogged fuel injector or bad fuel pump)
Faulty Engine Control Module (ECM)

How to Fix the DTC P1421 2009 Nissan Sentra?

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 P1421 2009 Nissan Sentra 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 P1421 2009 Nissan Sentra code?

Need more information on how to fix the P1421 2009 Nissan Sentra code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the P1421 2009 Nissan Sentra code diagnosed by a professional: Find a repair shop in your area

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 P1421 2009 Nissan Sentra Code

What does the OBDII code P1421 mean for a 2009 Nissan Sentra?

The P1421 code indicates a problem with the cold start control system, which is responsible for managing fuel delivery and emissions during cold engine starts.

What are common symptoms of the P1421 code in a 2009 Nissan Sentra?

Common symptoms include rough idle, poor fuel economy, increased emissions, and difficulty starting the engine in cold conditions.

What could cause the P1421 code to trigger in a 2009 Nissan Sentra?

Causes may include a faulty cold start control valve, wiring issues, a malfunctioning Engine Control Module (ECM), or problems with the intake air temperature sensor.

How can I diagnose the P1421 code in my 2009 Nissan Sentra?

To diagnose the code, start by checking the wiring and connectors related to the cold start control system, then test the cold start control valve and inspect the intake air temperature sensor.

What repairs are typically needed to fix the P1421 code?

Repairs may involve replacing a faulty cold start control valve, repairing wiring issues, or reprogramming or replacing the ECM if it is found to be defective.

Will the P1421 code cause my 2009 Nissan Sentra to fail an emissions test?

Yes, since the code is related to the emissions control system, it could lead to increased emissions and potentially cause your vehicle to fail an emissions test.

Can I drive my 2009 Nissan Sentra with the P1421 code?

While it may be possible to drive the vehicle, it is not recommended as the engine may perform poorly and could lead to further damage if the underlying issue is not addressed.

How can I clear the P1421 code from my 2009 Nissan Sentra?

You can clear the P1421 code by using an OBDII scanner to erase the code, but it's important to fix the underlying problem first to prevent the code from reappearing.

What is the cost to repair the P1421 code for a 2009 Nissan Sentra?

Repair costs can vary widely depending on the specific issue, but it typically ranges from $100 to $600, including parts and labor.