What is the Engine Failsafe Mode?

Schedule Oil Pump O Ring Replacement
Service Area

$104.39 - $1,909.25

Price range for all vehicles
Average rating from 130,153 customers who received a Oil Pump O Ring Replacement.

Whether you drive a Beemer, Toyota, Honda or any other make, your vehicle is engineered to protect itself from suffering catastrophic damage. This is essentially where the engine failsafe mode comes into play. Some people call it limp mode, and in other instances, it’s referred to as an engine cut off safety feature. Regardless of the name, understanding what an engine failsafe mode is, what to do when it happens, and how it’s fixed will help you prepare for this unfortunate and highly stressful situation.

Understanding the Engine Failsafe Mode

Modern cars, trucks and SUV’s are equipped with an OBD-II diagnostic system that monitors all vehicle systems including the:

  • Ignition System
  • Fuel System
  • Emission System
  • Drivetrain (including engine, transmission, axles)
  • Braking System
  • Vehicle Stability & Traction Control
  • Throttle Body
  • ...and much more

Using a series of sensors, the engine control unit (ECU) collects data instantly to ensure the vehicle operates as efficiently as possible. It also helps to make fine-tuning adjustments to these systems to keep the car, truck or SUV running safe and efficient. When one of these sensors detects a mechanical fault, usually in the engine or transmission of the vehicle, it will trigger an OBD-II trouble code that activates the engine failsafe mode.

What Happens When the Engine Failsafe Mode is Activated?

Once this failsafe or limp mode has been activated, the ECU will limit the vehicle’s ability to drive normally. In some instances, the ECU will permit you to limp home or to a mechanic but will restrict the performance or speed of the vehicle, so the damage will not get worse. This is where the term “Limp Mode” comes into play, by allowing the car to slowly get to a destination for diagnosis and repair.You may also notice it accompanied by the Check Engine Light turning on.

There are some instances that will cause the failsafe mode to disable the vehicle’s ignition or fuel system. This will cause the engine to “fail” to start. This can be a blessing, especially if there is minor mechanical damage that can progressively get worse if the engine continues to run.

What Causes the Engine Failsafe Mode?

Sometimes the engine failsafe mode is triggered by an actually damaged component, such as an oil pump, timing chain or belt, crankshaft or camshaft, or other internal engine components. It’s also common for damaged transmission components like inner gaskets, seals, the torque converter, mechanical gears, the input shaft, or even a damaged flywheel or driveshaft to cause the failsafe mode to activate.

It's also quite common for a sensor failure, or a damaged electrical connection to a sensor, to “accidentally” activate this warning system. Professional mechanics will fully inspect the vehicle to locate the exact source of this problem before clearing the codes and testing the repairs.

How is the Engine Failsafe Mode Diagnosed?

Since this safety system is activated through the ECU or powertrain control module (PCM), with transmission-related issues, a professional mechanic will start by downloading the error codes stored in these computers to begin the diagnosis process. Sometimes the engine failsafe mode is triggered due to a sensor failure or an electrical glitch. It’s also common for a security system fault to engage this warning light, which means it’s not always a mechanical issue that’s causing the failsafe.

Some people believe it’s possible to reset the engine failsafe mode through some less-than-reliable methods. This is not true, nor is it effective at resolving the problem. A professional mechanic should always be contacted to complete an onsite inspection to correctly diagnose the root source of the engine failsafe mode. This will permit them to recommend the right repairs or reset the error if it was a minor glitch.


Next Step

Schedule Oil Pump O Ring Replacement

The most popular service booked by readers of this article is Oil Pump O Ring Replacement. Yourmechanic’s technicians bring the dealership to you by performing this job at your home or office 7 days a week between 7AM-9PM. We currently cover over 10k cities and have 100k+ 5-star reviews... LEARN MORE

SEE PRICING & SCHEDULING

The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

Recent Oil Pump O Ring Replacement reviews

Excellent Rating


YourMechanic Oil Pump O Ring Replacement Service

Average Rating

4.9/5

Number of Reviews

130,153

Rating Summary
121,515
4,808
964
664
2,202
121,515
4,808
964
664
2,202

Keith

17 years of experience
307 reviews
Keith
17 years of experience
Chevrolet Tahoe - Oil Pump O Ring - Clermont, Florida
Very professional and knowledgeable.

Bryant

11 years of experience
347 reviews
Bryant
11 years of experience
Chevrolet Silverado 1500 - Oil Pump O Ring - Indianapolis, Indiana
Very knowledgeable and efficient

Theodore

15 years of experience
1137 reviews
Theodore
15 years of experience
Honda Pilot - Oil Pump O Ring - Everett, Washington
Theo was on time. He was very courteous and didn't mind me asking questions from time to time. I felt we had a good rapport. He did a great job of explaining everything to me and pointed out some things to me about the car as well. Says my car should last another 10 years at least..

Jeffrey

26 years of experience
862 reviews
Jeffrey
26 years of experience
Chrysler Pacifica - Crankshaft Position Sensor - Charlotte, North Carolina
Awesome

Need Help With Your Car?

Our certified mobile mechanics make house calls in over 2,000 U.S. cities. Fast, free online quotes for your car repair.

GET A QUOTE