9 Step Guide | GMC Sierra Check Engine Light Reset

The check engine light is the most important feature to protect the engine from getting damaged.

The check engine light indicates that something is wrong with your engine and can cause damage to it.

There is a problem with your engine or transmission if your check engine light appears.

If the light comes on, you should take it seriously and address any potential issues immediately.

You should not ignore the ‘Check Engine light’. Instead, take it seriously and try to find a solution.

Ignoring the warning further damages the engine or transmission system.

What is Check Engine Light?

The check engine light is a warning message that pops up on a vehicle’s dashboard.

The ‘Check Engine Light’ turns on automatically when the ECU detects a problem that can damage the engine or transmission system of the vehicle.

It is also known as the malfunction indicator lamp (MIL).

A loose gas cap, a broken catalytic converter, a problem with the wiring, faulty sensors, a problem with the spark plugs, a problem with the cooling system, or low or dirty engine oil, etc can trigger the check engine light.

How Does Check Engine Light Work?

How Does Check Engine Light Work

Check engine lights work by using sensors and diagnostic software to keep track of different parts and systems in the engine and transmission.

The light illuminates to warn the driver when a problem is detected.

The check engine light is part of the vehicle’s onboard diagnostics system (OBD-II).

OBD-II is designed to monitor and control emissions and engine performance.

The OBD-II system continuously monitors fuel systems, exhaust systems, and oxygen sensors.

When the OBD-II system detects a problem, it stores an error code in its memory.

The check engine light is then activated to inform the driver about the issue.

What Does It Mean When the Check Engine Light Is On?

The check engine light indicates that the engine or transmission system is malfunctioning.

The OBD system continuously monitors the engine and the transmission system.

If a problem is detected, the OBD system stores a diagnostic trouble code (DTC) in its memory, and the check engine light turns on to warn the driver.

GMC Sierra Check Engine Light Reset | 9 Step Guide

Using just 9 simple steps, you can reset the check engine light on your GMC Sierra without requiring special tools or equipment. Follow these steps to reset the check engine light yourself.

Step 1: Diagnose with an OBD-II Scanner

Diagnose with an OBD-II Scanner

You need to use an OBD-II scanner to reset the check engine light.

The OBD-II scanner tool connects to your truck’s onboard diagnostic (OBD) system and gets the error codes that caused the check engine light to come on.

Step 2: Find Out the Issue

Before resetting the check engine light, you need to address the underlying issue that caused the light to come on in the first place.

Before resetting the check engine light, you need to address the underlying issue that caused the light to illuminate in the first place.

Once the issue has been addressed, you may reset the light.

Step 3: Start the Engine

Start the engine of your GMC Sierra.

There is an exhaust gas recirculation system (EGR) in the GMC Sierra.

The exhaust gas recirculation (EGR) system is an emissions control system.

Its primary function is to reduce the amount of nitrogen oxide (NOx) emissions the engine produces.

The EGR valve regulates the amount of recirculated exhaust gas and directs it back into the engine’s intake manifold.

EGR systems contain a vacuum.

The EGR valve is opened and closed by this vacuum.

When you turn on the engine, the EGR system will run a self-test to make sure the valve works.

The check engine light will reappear if the valve is malfunctioning.

Step 4: Turn off the Ignition

Turn off the Ignition

The next step is to turn off the ignition.

You can do it by simply turning the key to the “off” position.

It clears the exhaust system of any residual pressure.

Wait about five seconds before moving on.

Step 5: Turn the Steering Wheel

Turn the steering wheel to the left and right without starting the ignition.

It will help relieve any pressure in the power steering system.

Step 6: Disconnect the Battery

Disconnect the Battery

The easiest method is disconnecting the battery to reset the check engine light on a GMC Sierra.

Make sure the engine is off, then open the hood.

Locate the battery and use a wrench to loosen the negative cable clamp.

Remove the clamp from the battery terminal and tuck it away, so it doesn’t accidentally touch the battery.

Step 7: Wait a Few Minutes

Before reconnecting the battery, wait a few minutes.

It ensures that the reset is complete and dissipates any residual power.

Step 8: Reconnect the Battery

Reattach the negative cable clamp to the battery terminal and tighten it securely.

Be careful not to damage the terminal by overtightening the clamp.

Step 9: Turn on the Ignition

After reconnecting the battery, put the key in the “on” position but don’t start the engine.

Wait a few seconds for the system to reset and the check engine light to turn off.

If the light doesn’t turn off immediately, try starting the engine and driving the vehicle for a few miles to see if it resets.

When to Reset Check Engine Light?

You should only reset the check engine light after addressing the underlying issue that caused it to turn on.

Simply resetting the light without fixing the problem will not make it go away and cause further damage to the vehicle.

After fixing the problem, you should reset the check engine light to make sure it doesn’t keep coming on.

Following these steps, you can also confirm that the issue has been completely resolved.

Final Thoughts

Resetting the check engine light on your GMC Sierra is a simple process that can be done with just a few basic tools.

Before you turn off the light, you should fix any underlying problems to ensure your truck runs smoothly and safely.

If you’re unsure how to reset the light or address the underlying issue, it’s always best to consult an experienced mechanic.

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