Q: Antitheft system causing car to not start

asked by on

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
  1. Home
  2. Questions
  3. Antitheft system causing car to not start

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

Q: Car is running roughly at around 45 mph

Hello. It is possible that all of the spark plugs and spark plug wires need to be replaced in order to fix the problem on your Plymouth Grand Voyager. Also, if carbon has built up in your intake, throttle body,...

Q: Immobiliser light flashing engine system failure and engine not starting.

Check the engine management control fuse (3amp) in the fuse box next to the battery. this fuse is only 3 amp and can easily burn out giving the symptoms you have. Also check the fuses in the fuse box below...

Q: Relay keeps getting hot and turning truck off

Hello. Your vehicle has over ten identical relays in the vehicle. You will need to be more specific with what relay is overheating. The most likely cause of an overheating relay would be a fuel pump relay getting hot from...

Related articles

How Long Does a Distributor O Ring Last?
The distributor is part of the ignition system in your vehicle and its purpose is to route high voltage from the ignition coil to the spark plug. The spark plug then...
How Long Does a Heater Control Valve Last?
Keeping the right amount of coolant in a car is essential in keeping the engine at the right temperature. Failing to have the right amount of coolant or even bad elements...
P2428 OBD-II Trouble Code: Exhaust Gas Temperature Too High Bank 1
P2428 code definition A P2428 trouble code signifies that the PCM has detected a problem in the exhaust gas temperature sensor circuit in bank 1, which subsequently contains the number one...