GMC Reduced Engine Power Reset | 3 Proven Methods

One of General Motors’ most famous and best-performing brands is GMC.

The GMC vehicles have a reputation for reliability, but the reduced engine power issue sometimes causes headaches for some owners.

If you’re tired of your GMC vehicle giving you the headache of reduced engine power mode, it’s time to say goodbye to this aggravating issue.

I am going to share some simple and effective methods of resetting the reduced engine power on your GMC vehicles.

These methods will enhance the engine’s performance to its optimal level and provide an enjoyable driving experience.

So don’t let reduced engine power hold you back anymore.

You’ll have an entirely new experience once you apply my methods.

You may also be interested in learning about the related articles:

What Does Reduced Engine Power Mean in GMC

GMC’s reduced engine power mode is typically a safety feature designed to prevent engine damage.

The reduced power mode is triggered when the ECM (Engine Control Module) detects one or more problems causing damage to the engine.

The typical sign of this reduced engine power mode is a yellow light on the vehicle dashboard or text like “check engine” or “low engine power.”

Generally, the warning light appears when fuel or airflow to the engine is reduced.

You will get the following 5 symptoms when engine power is reduced:

  1. Engine performance significantly decreases.
  2. Check engine or reduced power warning light appears on GMC’s dashboard.
  3. Slow acceleration.
  4. Sometimes the vehicle shuts down completely.
  5. Non-major parts shut down, such as the interior lights, audio system, power windows, and lighting system.

These symptoms indicate that your GMC requires maintenance and repair.

Take the symptoms seriously to avoid further problems.

What Causes Reduced Engine Power in GMC

Knowing the causes of GMC’s reduced engine power mode is essential.

Therefore, you can easily identify which component causes the problem and how to solve it.

Below are 6 of the most common causes of GMC’s reduced engine power light:

  1. Faulty throttle body
  2. Malfunctioning sensors like the mass airflow sensor or the throttle position sensor
  3. Issues with the fuel system
  4. Problems with the Engine Control Module (ECM).
  5. Issues with the exhaust system
  6. Clogged catalytic converter
  7. Electrical wiring issues can also cause the reduced engine power mode.

If you’re seeing the “reduced engine power” light, these are the first things you should check.

3 Proven Methods of GMC Reduced Engine Power Reset

There are 3 different methods to reset GMC’s reduced engine power mode.

These include quick resets, diagnosing the problem manually, and diagnosing the problem using an OBD-II scanner.

These methods are DIY, and you can perform them efficiently by yourself.

If the first 3 methods do not work, you can consider taking your vehicle to a repair shop as the final step.

However, the first 3 methods work in most cases.

Method 1: Quick Reset

Quick Reset

You can reset the reduced engine power mode by turning the vehicle off and back on again.

This trick works on most modern vehicles.

But it is noticeable that the quick reset process doesn’t solve the actual problem; it only turns off the warning light.

Here is a 4-step reset process:

  1. Turn off the vehicle.
  2. Disconnect the negative battery cable and wait for a few minutes.
  3. Reconnect the negative battery cable.
  4. Now turn on the vehicle.

Reduced engine power modes should be removed after following this 4-step method.

If the warning light still flashes, try the second method.

Method 2: Diagnosing Manually

Diagnosing Manually

Sometimes faulty parts are responsible for the “reduced engine power” warning light.

Therefore, checking and repairing/replacing faulty parts is the only way to solve the problem.

There are 2 methods of inspecting faulty parts: manually and with an OBD-II reader.

Examine the following components to determine the problem source:

  1. According to the owner’s manual, check the fuses and replace any damaged ones.
  2. Check engine oil. GMC’s engine oil should be changed every 7,500 miles.
  3. Check and replace the spark plugs. It is recommended to replace spark plugs every 30,000 miles.
  4. Check transmission fluid level and quality. Transmission fluid should be changed every 45,000 miles.
  5. Check the catalytic converter. It plays a vital role in engine performance, and any fault in the catalytic converter will reduce engine power.
  6. Check and clean the air filter.
  7. Check the oxygen and mass airflow (MAF) sensors individually.
  8. Visually check the engine ground connections, harnesses, circuits, connectors, and belts.

While checking the components mentioned above, if you find faults in any components, replace them.

After replacing the faulty parts, apply Method 1 and reset the reduced engine power mode.

Method 3: By Using an OBD-II Reader

By Using an OBD-II Reader

If you have an OBD-II scanner, use it to identify the faulty components that cause the reduced engine power problem.

If you don’t own an OBD-II scanner, you can rent or buy one as it is not too expensive.

Plug the OBD-II scanner into your vehicle’s OBD-II port and read the faulty codes.

The reader’s display might show P0120, P2135, or other similar types of code.

Each code indicates a specific problem.

Just search for the code in your browser to get details about the code.

Then take action according to the problem.

The OBD-II scanner can easily identify problems and help you find solutions quickly.

After resolving the specific component problem, restart your vehicle to reset to the reduced engine power mode.

Watch this video to learn how to fix the reduced engine power issue on your GMC.

Note: Most of the time, after applying these three methods, the reduced engine power mode will reset.

However, an experienced mechanic must diagnose your vehicle if the issue persists after trying all DIY solutions.

Experienced auto mechanics use an advanced scanner to identify the exact cause of the problem and solve it accordingly.

Sometimes the underlying problems require professional repair or replacement of parts.

How Much Does It Cost to Fix Reduced Engine Power in GMC

The cost of fixing reduced engine power depends on the vehicle model and problem type.

Typically, it costs between $40 and $500 to fix the problem.

But if reduced engine power comes on as a result of a severe problem, the cost of resetting may be significantly higher.

For example, if the problem is due to a faulty catalytic converter, resetting the reduced engine power in a GMC can cost over $2000.


Can a dirty air filter cause reduced engine power?

The engine gets less clean air when the air filter is dirty.

As a result, the engine fails to perform at its optimum level and triggers the reduced engine power mode.

Replacing the dirty air filter is the best solution to solving the issue.

It also increases engine performance and acceleration speed.

Can you drive your car on reduced engine power?

Yes, you can drive with reduced engine power because the problem is mostly minor.

But usually, as a mechanic, I advise people to avoid driving in reduced engine power mode.

Driving with reduced engine power for more than 100 miles can lead to major engine problems and costly repairs.

So you must take the warning light seriously and solve the issue before it becomes a major issue.

Can a fuel filter cause a car to lose power?

A clogged fuel filter reduces engine performance.

A fuel filter removes contaminants and impurities from fuel before it enters the engine.

When a fuel filter becomes clogged or faulty, it stops functioning properly and causes a vehicle to lose power.

How do I bypass limp mode?

You can bypass limp mode by disconnecting and reconnecting the negative battery terminal and resetting the electronic system.

However, I do not recommend disabling the limp mode because it is intended to protect the vehicle’s vital components, including the engine.

Bypassing limp mode without addressing the underlying issue may result in major engine damage.

Final Thoughts

If you act quickly, the reduced engine power won’t be a major problem.

Maintain your engine’s health and performance by identifying faulty components and replacing or repairing them.

However, remember that Method 1 only resets the reduced engine power warning light and does not completely solve the problem.

As a result, if you experience reduced engine power, you should take it seriously and use DIY techniques to fix the problem.

If you have issues performing the DIY methods, take your vehicle to a qualified mechanic for proper treatment.

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