Antitheft system causing car to not start five hundred v6...

Q: Antitheft system causing car to not start

asked by on February 09, 2016

The passive antitheft system is causing my car to not start.

Depending on where and how the security system was installed, this can change the possibilities of various issues and fixes. An aftermarket system put in by a private party could have been installed in different ways that could cause issues with the starting system or other sources depending on what the power is being drawn from. As where an OEM security system that came with the vehicle will have wiring diagrams and more diagnostic specified information about where the problem is coming from. Also there is a possibility that the dealer installed an aftermarket security system which falls in the middle of the other two. Possibly because the dealer may have had the schematics for the installation or in some cases they may have not. The best plan of action would be to have a qualified technician like the ones here at YourMechanic, perform an electric diagnostic on the security system in order to map out how the siren was installed. If the system wasn’t installed properly the car might not start. In this situation it can only be started with the supplied key fob with an auto start. In some bad cases it’s possible for the vehicle to not shut off at all.

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

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Fair and transparent pricing

Get a quote

What others are asking

When replacing a crank shaft part will the work send the timing chain off track?

Claimed by Kevin Gainer

Losing power while driving

Hi. If by losing power you mean the car lacked power, it's unlikely the problem is with the charging system. Lack of power indicates an engine performance problem. This could be anything from a clogged catalytic converter to a worn...

RPM fluctuates

With the age and mileage of your vehicle, it would probably benefit from a throttle body service including cleaning the idle air control valve. Over time, oil and carbon build up on the throttle blade so it does not sit...

Related articles

A Buyer’s Guide to the 2012 Ford Flex
The The 2012 Ford Flex takes on a completely different look when it comes to a CUV. The Flex can tow up to 4,500 pounds and seat seven passengers comfortably. It also has lots of standard features that its competitors...
A Buyer’s Guide to the 2012 Ford Fusion
Choosing Choosing a mid-size sedan for your family can be a tough call. There’s a lot of competition out there, including really popular models like the Honda Accord and Toyota Camry. Among all those, though, the 2012 Ford Fusion really...
How Car Keypad Locks Work
Pioneered Pioneered by Ford, keypads let you lock, unlock without keys Pioneered by Ford, keypad door systems began appearing on high-end car and SUV products in the early 1980s. Ford took advantage of the then-new digital computer revolution – the...