Skip the auto shop - Our mechanics make house calls

What Do the Immobilizer Warning Lights Mean?

A vehicle can be a big investment so it is important to make sure that no one can take your car without your keys. Nowadays, almost all vehicles have inbuilt immobilizer systems which prevent the engine from starting unless the correct key is being used.

Early systems had a simple code stored on the key which was read by the computer while trying to start the engine. Now, more advanced methods of encryption are used, so it is much harder to trick the system these days. The overall idea is the same though, whenever you turn the key, the car’s computer reads a code from the key and checks it against the codes that are currently known. If the computer finds a match, it will let you start the engine.

If a key match is not detected, a few things can happen. The engine may start and run for a few seconds before dying or the engine may not even turn over at all. A warning light is included on the dash to let you know how the system is reacting.

What the immobilizer warning light means

The indicator for the immobilizers behave similarly between different vehicles, but refer to the owner’s manual for specific information on your vehicle’s system. Generally, when you first start the engine, this light will illuminate for a few seconds showing that the correct key has been used. If the computer doesn’t recognize the code on the key, the light will flash multiple times. You won’t be able to start the engine until you use a recognized key.

If you have a keyless ignition in your vehicle, make sure that the key is close enough to register with the receiver inside the car. Even if the key fob has low or no battery power, most vehicles have a backup procedure so that you can still start the car. Information on this procedure will be included in the owner’s manual.

All vehicles can have multiple codes registered at a time so that you can have multiple keys to use the car. A factory scan tool or an already known key is needed to teach the car new codes.

Is it safe to drive with the immobilizer warning light on?

This warning light usually only comes on when the key isn’t recognized so you shouldn’t have to worry about this light coming on while you are already driving. If this happens, try taking the key out and reinserting it if you are having trouble getting your car started. If you are experiencing any troubles, check and verify that the key fob isn’t out of power.

If your car’s immobilizer system isn’t working properly, our certified technicians can help you diagnose any issues you are encountering.

The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details
Icon-warranty_badge-02

Skip the repair shop, our top-rated mechanics come to you.

At your home or office

Choose from 600+ repair, maintenance & diagnostic services. Our top-rated mechanics bring all parts & tools to your location.

Fair & transparent pricing

See labor & parts costs upfront, so you can book with confidence.

12-month, 12,000-mile warranty

Our services are backed by a 12-month, 12,000-mile warranty for your peace of mind.

Get A Quote

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

More related articles

The Traveler’s Guide to Driving in Malaysia
CraigBurrows / Shutterstock.com Malaysia is a popular destination for many tourists today. The country has amazing sights and attractions that you will want to explore....
Veteran and Military Driver Laws and Benefits in Idaho
The state of Idaho offers a number of benefits and perks for those Americans who have either served in an Armed Forces branch in the...
How to Avoid Back Pain in a Car
If you have back problems, sitting in a car for an extended period of time can be excruciating. Even without back problems, you could experience discomfort and soreness from...


Related questions

Q: Eco light in dash

The most common problem with these vehicles I have seen with the Eco Light flashing is a problem with the transmission solenoids. The transmission will need to be scanned to see if which solenoid is having problems in the transmission,...

Q: My security light is on and my 2005 Chevy equinox will not start..what's going on

Check to see if your battery voltage is low, that is below 12.6 volts. If the battery is discharged or faulty, the immobilizer system might set. If battery voltage is normal and you suspect the immobilizer system is on, to...

Q: Why does my car start to display a Maintenance Required Light?

Hi and thanks for contacting Your Mechanic. The "MAINT REQD" on the dash means that it is time to do an oil change. The light is on a timer of 4500 miles. This light will start to flash and then...