What does the red key warning light do and why is it on?
The red key warning light means there is a security error code. This light illuminates when the vehicle control modules see the ignition turned with a key that is not programmed to the vehicle or when there is an error within the security protocol of the vehicle’s security system.
Common reasons for this to happen
- Faulty key
- Dead key fob battery
- Faulty key antennae
- Faulty control module
- Electrical interference
Can I drive with the red key warning light on? (Can I drive in Fail-Safe Mode?)
In most cases, the vehicle will not start when the red key warning light is illuminated. It will have to be towed to a repair facility capable of programming and servicing the security system of your specific vehicle.
How do I fix a red key warning light?
- Replace the key fob battery
- If the concern persists, you will have to tow the vehicle to a repair facility capable of servicing your vehicle’s security system.
- Another option is to have a mobile key programmer to come to you and service the vehicle.
Frequently Asked Questions
What causes the red key warning light to come on?
- In some cases, this can be caused by aftermarket keys being programmed to the vehicle. They don’t always retain the memory the way a dealership key will.
My car wouldn’t start and the red key warning light was on but now it does, what’s wrong?
- In some cases, if there is a loose connection in the system it can cause an intermittent failure. Check the physical appearance of your keys. If the keys show signs of damage or wear they may need to be replaced.

At FIXD, our mission is to make car ownership as simple, easy, and affordable as possible. Our research team utilizes the latest automotive data and insights to create tools and resources that help drivers get peace of mind and save money over the life of their car.