What Is Limp Mode, And Why Do Cars Use It?

Dan Smith

Modern vehicles are equipped with multiple safety features that can assist drivers in different situations. Features such as ABS and cruise control help ensure safety and create the perfect driving experience. But there is one feature in particular that deserves a detailed explanation. That's limp mode. What is Limp Mode

What is limp mode?

This is a meticulous calibration that the transmission control unit or engine control unit uses to stop the motor when a powertrain component detects a problem. As the name suggests, this mode deactivates to reduce the impact of secondary systems such as air conditioning, radios and screens on overall performance. This immediate shutdown allows you to avoid serious incidents and drive safely. Limp mode is the car's way of notifying you of a serious problem that needs immediate attention.

How to detect limp mode

Various symptoms appear when the car goes into limp mode while driving. Limp mode limits the amount of power going to the engine and transmission.

Limited speed and RPM

The RPM is less than 3000, the speed limit is 35-40 mph, and the car cannot be shifted into 3rd gear. This makes driving on highways impossible. The best thing to do is take it to the nearest mechanic or safe place and have it inspected.

Poor performance

If you hear the engine growling or humming, it is probably due to malfunction and slow acceleration. Depending on the car model he may or may not be able to shift gears above 3rd gear.

check engine light

Limp mode is usually activated by a system failure that causes overheating. The Check Engine Light flashes or stays on. In some cases, the screen will also tell you why limp mode is being used. If the engine is overheating, it's a good idea to pull off the road and park in a safe place to let the car cool down. The cooldown process helps protect your vehicle from further damage.

stack gear

In cars with automatic transmission, gear shifts may be restricted by the car's system. Most of the time the transmission doesn't shift him above 3rd gear for engine safety. If the transmission isn't over 3rd he can't go very fast.

If you notice all these symptoms, your car is in limp mode.

Why is my car in limp mode?

In-car limp mode can be triggered for a variety of reasons. Let's look at some of them. A pro tip is to stop the car and do not drive it for a long time once the mode is activated to avoid further damage to the vehicle.


All wires in the car are connected to the engine. The engine powers all the parts necessary for operation. The electrical system is an important component of your vehicle, but it is also very delicate. Various factors such as engine heat, extreme cold, moisture and dirt can damage the wires. Broken cables can interfere with other systems in the car and cause limp mode.

Low transmission fluid level

Transmission fluid is a lubricant that prevents excessive friction between the components that make up the transmission system. Protects your transmission from damage and stress. If the fluid level exceeds a certain level, the pressure in the transmission system will drop and cause malfunctions. In automatic transmission cars, any failure in the transmission will automatically put the car in limp mode. Limp mode also activates when the transmission control unit determines that the vehicle's clutch is broken, damaged, or defective.

Malfunctioning sensor

Your car has multiple sensors that help it function efficiently. A speed sensor, for example, evaluates the driving situation of the vehicle. A throttle position sensor monitors pressure applied to the pedal, and a manifold absolute pressure sensor provides instant manifold data to the engine's control unit. The control unit activates limp mode when it cannot get accurate data from a large number of sensors. It is highly recommended to check all sensors to ensure they are working properly.

How to fix limp mode?

Limp mode requires a full diagnostic and a visit to the nearest car dealership. If you're stuck on the road, try these simple fixes.

  • Check fluid level. Check motor oil, coolant, transmission, brake level fluid, and power steering fluid. Make sure all these liquids are at optimum levels and free of accumulated debris. Transmission fluid is essential on this list if you have an automatic car.
  • Clean the mass airflow sensor. The MAF sensor adjusts the air-fuel mixture in the engine and can get dirty. A dirty sensor sends wrong values ​​to the control unit and the limp mode is activated. Simply clean it with an electric cleaner and your car will start working again. Be careful not to touch the sensor with your hand.
  • Check your air filter. A clogged air filter may be the reason behind the dreaded limp mode. Limp mode is activated when there is not enough air in the engine. Cleaning or replacing these may be the only things you need to do to get your car out of limp mode.
  • Check trouble code. You can properly diagnose the problem with an OBD2 scanner to see the trouble codes stored in your car's control unit.


Limp Mode is an in-vehicle safety system to prevent overuse of the engine when it is in critical condition. In this mode, no extra line of sight is drawn to the car and all functions are optimized until the problem is properly detected.