AutoCodes – GMC – P1400 2016 GMC Sierra

P1400 2016 GMC Sierra Code - Cold Start Emission Reduction Control System

Quick Answer

The catalytic converter must be warmed to efficiently reduce emissions. Common causes include Dirty Throttle Body, Dirty Air Filter, Dirty Mass Air Flow (MAF) Sensor. 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: P1400 2016 GMC Sierra indicates Cold Start Emission Reduction Control System.
Common causes: Common causes include Dirty Throttle Body, Dirty Air Filter, Dirty Mass Air Flow (MAF) Sensor.
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 250

How popular is this code, among other codes? Low

Repair Importance Level

Urgent (Diagnose now) (3 / 3)

Repair Difficulty Level

Advanced (Pro) (3 / 3)

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Table of contents Created and updated by William Orellana on Aug 13, 2022

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code P1400 2016 GMC Sierra Description

The catalytic converter must be warmed to efficiently reduce emissions. The cold start strategy is to reduce the amount of time it takes to warm the catalytic converter. During a cold start, the engine idle speed is elevated, and spark timing is retarded to allow the catalyst to warm quickly. This diagnostic monitors the following to build an exhaust energy model: Engine speed, Spark advance, Throttle position, Engine airflow, Engine coolant temperature, Engine runtime, Park/neutral position, Vehicle speed. The actual model is then compared to the expected exhaust energy model. The Diagnostic Trouble Code (DTC) will set when the actual exhaust energy model does not match the expected exhaust energy model.

OBDII Code P1400 2016 GMC Sierra - Cold Start Emission Reduction Control System - AutoCodes.com — P1400 2016 GMC Sierra Code - Cold Start Emission Reduction Control System

What does this mean?

What are the Possible Causes of the DTC P1400 2016 GMC Sierra?

Dirty Throttle Body
Dirty Air Filter
Dirty Mass Air Flow (MAF) Sensor
Intake manifold leak
Exhaust leak
Damaged, restricted, modified or enhanced exhaust system

How to Fix the DTC P1400 2016 GMC Sierra?

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 P1400 2016 GMC Sierra 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 P1400 2016 GMC Sierra code?

Need more information on how to fix the P1400 2016 GMC Sierra code? Get Access to Factory Service Manuals

Need Help with the 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 P1400 2016 GMC Sierra Code

1. What does the OBDII code P1400 mean on a 2016 GMC Sierra?

P1400 indicates an issue with the Cold Start Emission Reduction Control System, which helps reduce emissions during a cold engine start.

2. What are the common symptoms of code P1400 in a 2016 GMC Sierra?

Symptoms may include an illuminated check engine light, rough idling during cold starts, reduced fuel efficiency, and increased emissions.

3. What causes the P1400 code to appear on a 2016 GMC Sierra?

Possible causes include a malfunctioning cold start emission reduction valve, wiring or connector issues, carbon buildup, or a fault in the engine control module (ECM).

4. Can I drive my 2016 GMC Sierra with a P1400 code?

While the vehicle may still be drivable, ignoring the code can lead to increased emissions, poor fuel economy, and potential damage to other components over time.

5. How is the P1400 code diagnosed on a 2016 GMC Sierra?

A mechanic will use an OBDII scanner to confirm the code, inspect the cold start emission reduction system, check wiring and connectors, and test the valve's functionality.

6. How do you fix the P1400 code on a 2016 GMC Sierra?

Repairs may include replacing the cold start emission reduction valve, cleaning carbon deposits, repairing damaged wiring or connectors, or updating the ECM software if necessary.

7. How much does it cost to repair a P1400 code on a 2016 GMC Sierra?

Repair costs can vary but may range from $150 to $500, depending on whether the issue requires cleaning, part replacement, or labor-intensive diagnostics.

8. Can a dirty air filter trigger the P1400 code on a 2016 GMC Sierra?

While unlikely, a dirty air filter can indirectly affect engine performance and emissions, so ensuring it's clean is a good preventative step.

9. Does a P1400 code affect fuel efficiency in a 2016 GMC Sierra?

Yes, the P1400 code can reduce fuel efficiency due to improper operation of the cold start emission reduction system.

10. How can I prevent the P1400 code from recurring on my 2016 GMC Sierra?

Regular maintenance, including cleaning the emission system components, inspecting wiring, and addressing cold start issues promptly, can help prevent this code from reappearing.