Limp Mode: Symptoms, and Solutions

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Does it feel like your car is in child protection mode? Is your car stopping you from shifting past third gear or going faster than 40 mph? 

Don’t worry I can help you. If you are experiencing these issues your car is in limp mode. Limp mode is a safety feature designed to protect you from driving in unsafe conditions. 

In this post, I will help you determine if you are in limp mode, what caused it, and how to fix it. 

Let’s get started. 

What is Limp Mode?

Limp mode is a safety and security measure that your car’s computer will initiate if it suspects damage or a malfunctioning engine or transmission.

The “limp mode” is designed to prevent other issues from occurring. If it detects an issues your car will initiate the limp mode.

This will place restrictions on your cars driving such as speeds, RPM, and maximum gear. This helps drivers drive safe and prevent additional damage to your vehicle.

Signs that your car is in Limp mode

Identifying whether your car is in limp mode or experiencing other issues is not easy if you don’t know what you’re looking for.

It’s important to remember that, other issues with your vehicle can be misinterpreted as limp mode.

But, your car does not go into limp mode any time it experiences an issue.

1. Limited Speed and Poor Performance

 During limp mode, the ECU will reduce the speed or performance of your vehicle’s engine. This means that you will only be able to drive between 30 and 45 mph.

In limp mode, the aim is to prevent any additional damage to your car. One wa it does this is by keeping your RPM and engine power restricted. Typically, during the limp mode, vehicles won’t be able to exceed a maximum of 2,000 or 3,000 RPM. The maximum RPM will depend on the vehicle make and model. 

This will keep the wear and heat inside your vehicle’s engine down and effectively reduces the chances that any potential engine issues become worse. 

You can easily see your RPM on your dashboard. The RPM is typically shown in thousands which means your car will only reach an RPM of 2 or 3 on your dashboard. 

You can also check out the video below to learn how your odometer works. 

2. Can’t go past third gear

If you find that your car won’t shift past third gear this is a clear indication that your car is in limp mode.

This sign is more common with automatic vehicles. The computer inside your vehicle will prevent your transmission from shifting beyond third gear.

This is related to keeping speed and RPM down. In some cases, it might be hard to notice if your in areas where you’re not driving above 40 mph.

3. Check Engine Light turns On

The check engine light almost always come on when your car is in limp mode. In limp mode, there is typically another issue inside your engine.

If you experience another sign on this list along with your engine light turning on frequently or staying on, this is a clear sign that your car is in limp mode.

It’s important that you don’t ignore your check engine light. Always have your car checked out to ensure that your engine is in proper working condition.

4. Engine is Overheating

In the most serious cases, you might notice that the engine is overheating. This is a sign that you should pull over and give your car time to cool off before driving any further. Giving your engine and transmission a break reduces the damage they might take.

5. Unresponsive or Slow Gas Pedal

You might be used to a responsive gas pedal, but if you’re in limp mode, the responsiveness of your gas pedal will typically decrease when in limp mode.

This is typically more noticeable with newer vehicles. But, if you have to push down harder before you experience any engine rev from your vehicles, then it’s likely that your car is in limp mode.

This transition is typically sudden, and this is one way you can determine that it’s not related to other issues.

In most cases, when gas pedals lose responsiveness, it’s a gradual process due to wear and tear or damaged throttle components.

When your engine goes into limp mode, the transition is fast and is a safety measure to protect your engine and yourself from driving your vehicle under unsafe conditions.

What Causes Limp Mode?

Many things can cause limp mode to take over your vehicle. The causes listed below are the most common and easiest to identify. 

If your car does not have any of the problems on this list, you should take it to a professional. Professional mechanics can determine the exact reason the limp mode was triggered. 

It’s best to inspect your vehicle yourself for any of the issues listed below. If you don’t have any, this does not mean that your car is in good condition. Reach out to a mechanic to get a professional opinion if you can’t identify the issues yourself. 

The most important thing is to act fast. Don’t continue driving your vehicle for extended periods if the limp mode was triggered. 

1. Low Transmission Fluid

Transmission fluid is a lubricant that reduces friction in the transmission system. It also protects the transmission from wear and tear. It’s good to keep the fluid topped up to keep your car in working order.

Reduced pressure can develop in your car’s transmission system if there isn’t enough fluid. This can lead to the transmission not working right and Limp Mode activating.

2. Wire Damage

All the electrical wires in your car connect to the engine. They provide power to everything your car needs to function. This makes the electrical system one of the most crucial of your car’s inner workings.

The electrical system is also the most fragile. The heat from the engine, extreme cold, moisture, and dirt can cause the wiring to short out or break down. These damaged wires can interfere with your car’s other systems and cause Limp Mode to activate.

3. Failing Clutch or Transmission

The clutch or transmission allows your car to change gears. This is the part that engages and/or disengages the gear system to select how fast your car can go.

Limp Mode activates if the ECU detects that the clutch in your car breaks, gets damaged, or becomes faulty. Problems in the transmission like bad solenoids can also activate Limp Mode.

4. Engine Knock or Misfires

Knocking sounds coming from your engine usually can point you towards different problems. The sounds stem from the air and fuel mixture in your engine being off or incorrect. This makes the mixture burn-in uneven pockets instead of uniform bursts.

Your car might go into Limp Mode if it experiences consistent knock or misfires. 

5. Bad Sensors

Your car contains many sensors it needs to function. For example, the speed sensor measures how fast your car is moving. The sensor that detects how much you’re pressing on the gas is the throttle position sensor (TPS). They work together with other sensors to keep your car in working order.

Your car’s ECU will turn on Limp Mode if it fails to get a good reading out of any of the car’s many sensors. You should make it a habit to check your sensors to see if they are still working as intended.

6. Overheating

When your car cannot deal with the heat the engine generates, it overheats. This can damage your car’s components and hinder performance.

Constant overheating can cause your car to go into Limp Mode. The ECU will cut power to some parts of the engine to let cool air lower the engine temperature.

7. Overboost

Overboost happens when a turbocharged engine takes in more air than what the ECU would allow. This increases the engine’s power output at the expense of possible damage. If the ECU detects that overboost happens due to component failure, it will trigger Limp Mode. This avoids catastrophic engine failure.

8. Vacuum or Boost Leak

A vacuum/boost leak occurs when more air than the ECU allows enters into the vehicle’s engine. The difference lies in the fact that a vacuum/boost leak comes from faulty air intakes. If the ECU detects that the air to fuel ratio is not what it expects, it will trigger Limp Mode.

9. Missing Emissions Equipment

Customizing your car to remove the muffler will also remove the associated sensor. The ECU will engage Limp Mode if it detects that any sensors are missing. After all, car manufacturers spend a lot of time and money to engineer the entire vehicle. That includes its emissions equipment.

10. Other Potential Issues

The reality is that there are many causes that can cause your car to go into limp mode. The list above is the most common reason that cars go into limp mode but not a definitive list. 

  • Transmission valve body
  • Overboots or under boost ( Turbo engines )
  • Faulty engine sensors
  • Damaged wire harness
  • Ground connection
  • Low battery voltage
  • ABS or Brake system issues
  • Wheel speed sensor
  • Manifold absolute pressure (MAP) sensor
  • Throttle position sensor (TPS)
  • Engine overheating
  • ECU needs calibration
  • Car accident
  • Blown fuse for critical vehicle systems
  • If water gets on an engine sensor, for example, after a car wash.

Is it dangerous to drive a car in Limp Mode?

The check engine light almost always come on when your car is in limp mode. In limp mode, there is typically another issue inside your engine.

If you experience another sign on this list along with your engine light turning on frequently or staying on, this is a clear sign that your car is in limp mode.

It’s important that you don’t ignore your check engine light. Always have your car checked out to ensure that your engine is in proper working condition.

is Limp Mode Bad?

No, limp mode is not bad. Limp mode is a sign that there are issues inside your vehicle that need to be addressed. Overall, limp modes are beneficial because they help keep you safe and help prevent your car from getting more damaged. 

How To Reset Your Limp Mode?

Resetting your limp mode should only be done once all the issues have been addressed. 

Manually resetting the limp mode is dangerous and can lead to more serious damage if you don’t determine what the cause was. 

  1. Use an OBD scanner to reset all error codes 
  2. Unplug and plug in your battery 
  3. Turn off your vehicle and let it rest for 5-10 minutes 
  4. Have a mechanic inspect your vehicle 
  5. Repair the main cause of the limp mode

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