Low Engine Power Warning (What does it mean?)

Each day will feel sunny and bright when the vehicle runs smoothly. When something goes wrong, it can feel like the whole world is on fire. Nothing is more disheartening than seeing the Reduced Engine Power Warning alert on the dashboard or feeling the car’s performance fall off the map.

We explain the reason for the decreased engine power warning to help you understand the situation. Also, we discuss what causes this warning and offer suggestions on how you can fix it. 

Low Engine Power Warning

The Engine Power Reduced alert indicates that your vehicle's performance is reduced. A system fault is detected by the PCM and an alert message will be displayed. It is possible that the engine will not operate normally when the PCM alerts.

You may not be able to accelerate or shift the vehicle due to reduced power. In extreme cases, the PCM will restrict fuel to the engine, leaving you with a car that won’t run.

This is also known as the failsafe mode. However, it’s also known as the limp mode because the warning gives you time to drive home without causing further damage to the engine or transmission. 

Low Engine Power Causes

Low engine power is usually caused by bad sensors such as an MAF or oxygen sensor. You can also get it from a loose connection. It can also be caused by a blocked catalytic converter.

You should not just replace parts that are defective.

Checking the OBD2 scanner for any trouble codes is the best and easiest way to diagnose the reason behind the Reduced Engine Power Warning message. The message will almost always indicate that there are trouble codes in your system. You can avoid spending a lot on replacement parts by using this method.

These are just a few other reasons why the warning about reduced engine power is coming on.

1. The Loose Connection

Each major part of your car is wired. An engine can go into fail-safe mode when there is an electrical short, or if one of the wires becomes damaged. This problem can also exist if you have a loose clamp or a ground wire isn’t properly secured. 

While a loose connection is simple to repair in most cases, it isn’t always easy to find. For the defect to be found, it would take a complete inspection of all systems. 

2. Defective Oxygen Sensor

The exhaust is monitored by oxygen sensors. The ECU will adjust the ratio of air and fuel to ensure that there's enough or not enough oxygen.

However, a defective sensor can send faulty information back to the computer, causing adjustments to be made that shouldn’t. The result is an imbalance of the fuel and air mixture. It can cause poor engine performance, as well as problems with the engine.

RELATED: 5 Signs That Your Oxygen Sensor is Not Working (O2)

3. Trottle Body Issues

These warnings could be issued because of the many parts in your throttle body. First of all, let air in the engine through the butterfly valve. The proper air volume cannot be maintained if the valve is broken.

The valve may also become carboniferous, which can cause issues. When the engine can’t get enough air, it’s going to misfire and sputter while causing warnings on the dashboard.

The throttle position sensor is located near the butterfly valve. It must work correctly to permit free air movement. The sensor measures the position of your gas pedal and tells the computer how to open your butterfly valve. The sensor can be damaged, so the valve won't get correct information and will stop breathing. 

RELATED: 8 Symptoms of a Bad Throttle Body (& Replacement Cost)

4. Malfunctioning ECU

Engine Control Unit controls the whole operation. So that the ECU can make the correct adjustments, all of the sensors are communicating with it. If the air-fuel mixture isn’t right, it’s the ECU that alters what’s happening for better performance.

Any number of problems can happen when the ECU goes down. Poor performance can lead to poor engine operation. 

RELATED : 5 Signs That Your Engine Control Module (ECM), Is Not Working

5. Failure Mass Airflow Sensor

Between the intake manifold to the engine air filter, you will find the mass flow sensor. The sensor is used to determine the volume and pressure of air entering your engine. 

These measurements will be sent to ECU for the correct fuel ratio. The MAF sensor can fail, and the incorrect data may be sent. If this happens, warning lights will illuminate. 

Related: 8 Warning Signs That Your MAF Sensor Is Not Working

6. Conversion catalytic converter clogged

The catalytic converter is located after the exhaust manifold. This vital part is responsible for converting harmful exhaust gases to less dangerous contaminants. If the engine hasn’t been running properly or as the vehicle ages, the catalytic converter can become clogged.

The vehicle will fail the emissions test. You will also experience engine performance problems. It won’t always illuminate the Reduced Engine Power Warning, but you can expect the Check Engine Light to come on at a bare minimum. 

RELATED : How to Clean and Maintain a Catalytic Converter Without Removing It

7. Transmission failure

Transmission problems are not fun and can cause a lot more headaches. You can expect error codes to be displayed if the transmission slips or the fluid is low.

While people don’t think a reduction in engine power is linked to the transmissions, these two systems are intertwined. If none of the other culprits are to blame, it’s time to take a look at the transmission. 

Low Engine Power Repair

A Reduced Engine Power Warning repair cost can range from $0 to $2,500. The only way to know the exact cost would be to determine what’s causing it.

A scanner for engine codes can be used to pinpoint where fault lies. OBDII scans fault codes to show what system might be responsible.

Ideally, you would notice a loose connection, which wouldn’t cost you anything to fix if you can re-establish the link. The cost of replacing or changing the ECU can be expensive and could lead to your car being scrapped.

The Reduced Engine Power Warning warning light should not be on. The Limp Mode should be turned off immediately after it is activated. To let others know that you're having problems, turn on your hazard light.

If you have more than a few miles to drive, it’s recommended that you have the vehicle towed instead. You don’t want to end up stranded on the side of the road or cause an accident because of the lack of power.