"Reduced engine power" message on Chevy Impala

Reduced Engine Power Message On Chevy Impala

Reduced engine power is one of the most common error messages on the Chevy Impala dashboard. What causes it, and how can you fix it?

This error message has many causes depending on the car model. It can result from a faulty accelerator pedal sensor or throttle position sensor. Also, it can be from a clogged catalytic converter, malfunctioning ECU, or engine problem.

Regardless, don’t drive your car over a long distance with the reduced engine power warning message. Read on for details on causes and how to fix the problem.

"Reduced engine power" message on Chevy Impala
“Reduced engine power” message on Chevy Impala

What Does The “Reduced Engine Power” Message Mean on Chevy Impala?

The reduced engine power message on the dashboard means the powertrain control module (PCM) has intentionally reduced the engine’s performance. That usually happens when an underlying problem exists. PCM reduces the engine power to reduce the chances of damage to the engine.

Your car will have a drastic reduction in performance. This means it will not accelerate as fast as it used to, even if you press the gas pedal to the floor.

What Is Reduced Engine Power Mode?

It is a fail-safe mechanism that helps to protect your car from further damage.

When your car Chevy Impala switches to a reduced engine power mode, acceleration is impossible. It will maintain a constant speed even if you step on the gas pedal to the floor. The vehicle may become undrivable if PCM completely cuts the fuel supply.

The reduced engine power mode is inbuilt into the car system for safety. It simply prevents you from damaging the engine by running at minimum power.

Is It Safe To Drive When The Light For Reduced Engine Power Is On?

Yes. You can continue to drive your Chevy Impala or any other car model when this mode is active, but not for a long distance. It allows you to go back home or drive to the nearest auto repair shop. At reduced power, the drivability will be at its worst. You will not accelerate and may use more gallons of gas per mile. The car will crawl at a snail’s pace.

Fix the reduced engine power at the first opportunity. It may take a few hours but can still give you enough time to proceed with your journey.

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What Are The Causes?

The reduced engine power message on Chevy Impala can result from different causes. When it appears on the dashboard, look for other symbols that come with it. Different lights may also come on to help you identify possible problems.

The following are the most common causes of reduced engine power message in Chevy Impala:

Causes of "Reduced engine power" message on Chevy Impala
Causes of “Reduced engine power” message on Chevy Impala

Faulty Pedal Position Sensor

The accelerator pedal position sensor reads commands from the driver. Based on that data, the engine control unit knows the load requested by the driver and implements it immediately. That is how the car can accelerate or decelerate when you press or depress the gas pedal.

If the pedal position sensor becomes faulty, the car fails to respond to your commands to accelerate or decelerate. Such a sensor can also transmit erroneous information to the engine control unit. That is particularly dangerous if you are on the road because you cannot control the vehicle.

So, the engine control module does not get the information it needs to command the engine to perform as expected.

Faulty Throttle Position Sensor

Throttle position sensors play a vital role in the drivability of your Chevy Impala. They constantly monitor the throttle position to know how much gas you apply. The same information is also necessary to determine when to upshift or downshift gears in automatic and continuously variable transmission systems.

If the throttle position sensor is faulty, gear shifting becomes practically impossible. The car will not accelerate or decelerate as you command it. The PCM detects this problem and may reduce engine power, which allows you to drive at a constantly safe speed.

Catalytic Converter Clogged with Debris

A catalytic converter plays a role in reducing poisonous gasses from your car to less harmful forms. For example, it converts the more harmful carbon monoxide gas in the exhaust to safer carbon dioxide. It reduces the emission hazards and allows your vehicle to remain compliant.

All modern cars come fitted with a catalytic converter. However, some people believe that it reduces the engine’s performance. That is far from the truth unless there is debris clogging it. A catalytic converter does not block the exhaust gasses!

Debris and soot may clog the catalytic converter over time. That constricts the passage or blocks exhaust gasses, which reduces engine performance.

Engine Performance Problems

The engine is a complex mechanism with many systems working synchronously to ensure optimal performance. If any of these individual systems fail, the reduced engine power message appears on the dashboard.

For optimal performance, your car’s engine requires a functioning fuel pump, cooling system, fuel injectors, spark plugs, etc. A problem with these systems and components will result in reduced engine performance. For example, a faulty fuel pump will not deliver the required amount of fuel for acceleration.

Faulty ECU

Modern vehicles have minicomputers called modules that communicate with the engine control unit (ECU). ECU also relies on sensors to optimize engine performance. Therefore, a communication problem or sensors is enough to reduce the engine power. But what happens if the ECU is faulty?

ECU is the brain of your car. If it cannot process all the data, controlling the engine performance becomes impossible. The result will be reduced power or responding vehicle, regardless of the position of the accelerator pedal.

How To Fix This “Reduced Engine Power” Message On Chevy Impala Cars?

Fixing the reduced engine power warning message on a Chevy Impala is not as easy as many people think. It requires advanced DIY skills and an OBD2 scan tool to identify the problem. And since there are many possible causes of this problem, it is also a time-consuming process to find the issue.

How to fix this "Reduced engine power" message on Chevy Impala cars?
How to fix this “Reduced engine power” message on Chevy Impala cars?

If you are up to the task, carry out the following:

Visual Inspection

Most causes of reduced engine power are not clear. However, a visual inspection can help you identify some of them. Check the car components and systems, such as clogged air filters. That can be obvious, but not with an airflow sensor, fuel pump, or catalytic converter.

Fortunately, you can test your airflow sensor to know if it is faulty or not. To do so, park the car on a flat surface and secure the wheels. Start the engine and tap the airflow sensor. If the engine stutters, the sensor is likely faulty.

Scanning For DTCs

Chevy Impala, like all modern vehicles, stores a fault code when there is any issue in any of its systems. So, the next step is using an OBD2 scanning tool to read any stored codes to help you identify the problem.

Your OBD2 scanner may return one or more codes. Depending on the tool, you can get code descriptions to help you know where to start your diagnosis. Some will pinpoint the faulty sensor you need to replace or systems to check.

Checking Technical Service Bulletins (TSBs)

You can learn how to fix reduced power in a Chevy Impala by checking the TSBs. If you are lucky, you can find the repair procedure for your specific vehicle model, saving you time and money.

Alternatively, you can consult the factory repair information from a manual or database. You will find comprehensive diagnostic and fixing procedures. However, you should ensure you get your vehicle model right by researching it in advance.

Hopefully, you can diagnose and fix the reduced engine power in Chevy Impala. If you don’t have the DIY skills or necessary tools and equipment, contact your mechanic or take the car to an auto repair shop. It will help you save time and prevent costly damages.


Reduced engine power message on Chevy Impala is one of the most common problems. It results from many causes, including faulty pedal position sensor, ECU, throttle body sensor, catalytic converter, etc. Fortunately, you can still drive your car back home or to an auto repair shop. Also, you can diagnose and fix the problem with your DIY skills. Otherwise, contact a professional mechanic to help you.

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