The P1400 Code on Chevy Silverado (Meaning, Causes, and Fixes)

One fine morning you may notice that your truck is idling rough when plugged in and you are getting a check engine light. Why am I talking about these specific symptoms?

This is everything the code P1400 on a Chevy Silverado is all about. It is an emission reduction control system diagnostic code for cold starts. Depending on the model and year of your car, this may change.

Confused about how to solve the issue? Think no more! In this article, I will discuss every detail you need to know about the P1400 code on your Chevy Silverado. Read till the end to find out all details about the code and its fix!

What Does P1400 Code Mean On Chevy Silverado?

To effectively minimize emissions, the catalytic converter needs to be preheated. The goal of the cold start approach is to reduce the time needed to warm the catalytic converter.

In a cold engine, the idle speed is increased and the spark timing is delayed to allow the catalyst to warm up faster.

During the first two minutes following a cold start, the car executes this test to diagnose a problem with a cold start. The RPM, spark advance, MAF air flow, throttle position, coolant temperature, run time, park/neutral switch position, and vehicle speed sensor are all monitored throughout this test.

Then, the expected exhaust energy model and the actual model are contrasted. This code may be set by any loading of the engine that reduces engine RPM, such as partial clutch application, cycling of the air conditioner, etc.

Let’s look at what the different parts of the code P1400 signify:

• P- Powertrain, the assembly of parts that move your car forward.
• 1 – Manufacturer Specific Code
• 4 – Exhaust Monitoring System
• 00- Specific Problem (in this case Air Flow circuit problem). 

What Happens When the Code P1400 On Chevy Silverado Appears?

There is usually a cold start. With that, the car moves at a speed of less than 2 km/h. And without any input from the accelerator pedal, the engine is in idle.

The truck may sustain the idle and a check engine light displaying the code P1400. And it will spew white/grey, possibly slightly blueish smoke. On plug 7, there may be a small amount of oil residue (drive side near the firewall).

Within the first 70 seconds of startup, this DTC runs for 15 seconds. And you should notice that there is more than 80mg of airflow per cylinder. When a cold start has been identified, this diagnostic is run once per trip.

The Silverado runs poorly, is cold, idles slowly, stalls, hesitates, and flashes. Additionally, the malfunction indicator lamp (MIL) illuminates after starting the Silverado.

When the truck first starts up, it runs poorly for about 30 seconds before smoothing out and running smoothly. Depending on how poorly the engine runs, a code 1400 may be generated.

The truck runs great as long as the engine is warmed up. However, the issue reappears if it gets cold, or if it sits overnight.

What Causes Code P1400 On Chevy Silverado?

The engine control module (ECM) may interpret the temperature difference between the intake air temperature (IAT) sensor and the engine coolant temperature (ECT) sensor.

They will be outside of a calibrated range. Especially after determining that the ignition OFF time requirement has been met at start-up. This is when the P1400 code sets in.

But why does it happen? Fuel may be the cause of the issue. The 6.2 L and 5.3 L engines are reportedly so tight that the valves clog and stick.

The collection of gunk in the throttle body can cause this issue. This is why often cleaning the throttle body relieves it.

How To Fix The P1400 Code On The Chevy Silverado?

Step 1- Inspection

Inspect the air intake system if they are modified, damaged, or restricted. Check for dirt or deteriorating air filter elements and water intrusion. Make sure that the crankcase ventilation system is in correct operation.

The MAF sensor is important with this code. Any leak in the vacuum or the intake manifold should be checked. And other un-metered air downstream should be checked in the MAF as well.

This may be related to faulty wiring. Test all of the wiring involved in EGR operation. A computer’s high or low circuit voltage error codes are frequently attributed to improper wiring.

Check to see if the EGR valve is leaking. To do that, spray water on it while the engine is running. If water steams off, the valve is leaking and is the cause of your problem.

Step 2- Troubleshooting (Cleaning and Replacements)

After you have looked for any problems with the air filter and air duct, troubleshoot if you find any. A fresh air filter typically resolves this error.

Additionally, it is advised to clean the MAF sensor and the throttle body. You can check the air intake system, and clean the throttle bore, and the mass airflow sensor components. If nothing works then change the plugs, and Mass Air Flow sensor. This should do the trick.

If there are signs of damage, please repair or replace it. The EGR valve can be cleaned free of cost. If that does not solve the issue, you might have to replace the DPFE sensor, which is expensive and also might not solve the issue.

There is an updated driver’s side valve cover due to excessive PCV vapor pull. They have a new PCV baffling system on the cover. This falls under the crankcase ventilation system for correct operation as it is integrated into that valve cover. Changing this valve cover and the #7 spark plug may help any oil bleeding issue.

To properly correct this condition, the revised Bulletin of 2012 states that you must perform both relocations of the ECT sensor and the engine coolant heater cord.

Now, you will need to clean the gunk accumulated in the engine. To clear the gunk from the valves, have GM perform a Top Engine Clean on the car. However, the 5yr/100K drivetrain-only warranty does not cover it.

Alternately, run the engine through a fuel system cleaner. It is advised to use Techron Concentrate Plus Fuel System Cleaner. It might require 1-2 tanks of gas (with the treatment included) depending on the amount of buildup.

Step 3- Protect the Emission Control System

Make sure your battery has a charge, is not rusted, and is not leaking. Even if you think your battery is in good shape, you can often jump-start your car by using a jumper cable from another vehicle.

Older vehicles should have their fuel lines to the engine flushed or have fuel injection service performed if the engine is cold. Do not be afraid to keep trying to warm up the engine by constantly cranking it even though it is cold outside.

Because the engine tends to warp the same way wood does during extreme cold. The worst that could happen is that too much fuel will enter the carburetor and cause flooding in the system. This will not harm the car.

If this occurs, wait 20 minutes before starting to crank again. Moreover, many cars take a very long time to start. And one of the main causes is bad spark plugs.

Please remove and replace your spark plugs with new ones. Spark plugs deteriorate over time, and even though you can hear the engine cranking, the car won’t start.

How Much Does It Cost To Fix The Chevy Silverado P1400 Code?

1. Inspection Charge

On average, it costs between $44 and $56 to inspect the emission control system of a Chevrolet Silverado.

2. MAF Sensor

Replacing the MAF sensor will require expert intervention. The sensor itself ranges from $170 to $251. The estimated cost of labor and parts respectively is between $32 and $40 and between $138 and $211.

3. Top Engine Clean

Depending on where you live, the GM Top engine cleaning service can cost between $100-200. It can also go up to $500 depending on what you do.

4. Fuel Cleaner

The price of the fuel cleaner depending on quality ranges between $50 and $80. The Techron Concentrate Plus Fuel System Cleaner costs around $18.79 a bottle.

Can You Drive Your Chevy Silverado With Code P1400?

Yes, you can. A P1400 code is regarded as moderate. It means that although the car will still operate, performance may be significantly reduced.

Users experience a rough idle at start-up. But that too clears up after about 15-20 seconds.

The major risky element might be a misfire. But nothing here should stop you from driving. It is safe to drive with the P1400 code on a Chevy Silverado.

Frequently Asked Questions (FAQs)

Conclusion

The code P1400 is a DTC code that is mild to moderate. If you carefully read this article, you will be able to fix the code without breaking the bank.

Moreover, the code is mild to moderate. So it is safe to drive when the code sets in your Silverado.

I hope this article will help you learn about and fix the code P1400 in Chevy Silverado. Cheers!