A vehicle that won’t start, won’t spin the starter, or will start and immediately die is one of the most common symptoms of a problem with the vehicle’s anti-theft system, and this problem can be a bit complicated to resolve.
Passive anti-theft systems are designed to prevent the car from being stolen while perimeter anti-theft systems are designed to prevent people from stealing stuff in the car. Passive anti-theft systems prevent the car from starting if the wrong key is used or somebody is trying to hotwire the car. Meanwhile, perimeter anti-theft systems will sound an alarm if somebody opens a car door while the system is armed. This type of system won’t prevent the car from starting.
Passive anti-theft systems are designed to prevent the car from being stolen while perimeter anti-theft systems are designed to prevent people from stealing stuff in the car. Passive anti-theft systems prevent the car from starting if the wrong key is used or somebody is trying to hotwire the car. Meanwhile, perimeter anti-theft systems will sound an alarm if somebody opens a car door while the system is armed. This type of system won’t prevent the car from starting.
–Richard McCuistian, ASE Certified Master Automobile Technician
Note that getting around a faulty anti-theft system is a lot easier said than done on most platforms and will typically require professional help. Having said that, if you’re sure that the service theft deterrent system is the reason why your car won’t start, here are a few things you can try:
Your car’s mechanical key can be used to disable a perimeter-type anti-theft system but not a passive anti-theft system.
Turning the key up to the “on” position for a few minutes can cause the anti-theft system warning light to go off and get your car to start. But again, this varies tremendously from platform to platform.
First, make sure that the parking and low-beam headlights, dome and courtesy lights, horn, and electric door locks are all working as they should.
On most vehicles, these components send various signals to the powertrain control module (PCM), alerting it whenever there are issues like a missing signal and out-of-range signals.
If the PCM can identify an issue because of the signals from these components, it can disable the anti-theft system and log a diagnostic trouble code (DTC).
If all the components are operational, make sure all their switches are in their normal on and off positions via voltage drop tests. Doing so will help you identify the faulty parts and circuits.
The diagnostic and repair procedures might require extensive automotive repair knowledge, so if you’re not familiar with resolving trouble codes, it’s best to leave the job to a professional mechanic.
Car dealers or certified repair outlets might be the only ones who can access your vehicle’s anti-theft system, depending on its year, make, and model.
Most factory-installed anti-theft systems require specific scan tools that can be quite tricky to use if you’re not familiar with the diagnostic process.
Most vehicles with an anti-theft system come with ignition keys with a coded transponder chip that sends a signal to the receiver in the ignition switch.
If the anti-theft system sends a no-go signal to the PCM, the engine computer will disable the ignition, fuel system, or starter.
Most anti-theft systems are integrated with other electrical circuits to form a multiple-circuit system.
So when it comes to diagnosis and repair, it’s important to have make-model-specific wiring diagrams and test procedures. These will help you break down the system into subcircuits and identify the faulty component.
Factory-installed anti-theft systems act as immobilizers and keep your vehicle safe from thieves. But if your car doesn’t have one, you might want to check out these foolproof devices.
This device locks the steering wheel to the brake or clutch pedal to immobilize the vehicle. A steering wheel brake lock is made from hardened steel, so a hacksaw or power drill can’t break it.
The wheel lock works like the standard tire clamp. It prevents one of the wheels from rotating, keeping the vehicle parked in the same spot.
A Faraday bag is a small pouch that blocks electromagnetic fields that come from keyless entry systems. It’s suitable for drivers who have keyless entry systems in their vehicles, as it blocks an electronic signal that can unlock vehicle doors.
There are GPS trackers that fit onto OBD ports and provide your vehicle’s real-time location. Although a GPS tracker can’t prevent thieves from taking your car, it does come in handy when tracking your vehicle’s whereabouts.
Anti-theft systems and devices can only do so much. So, as a car owner, you must be thorough when it comes to keeping your vehicle safe. Aside from anti-theft devices, you can follow these practices to prevent theft.
Many drivers like to leave the engine running while they make a quick run to the restroom or nearby store, increasing the risk of someone breaking in and stealing their car.
Always take your key with you wherever you go to prevent this from happening.
Parking in well-lit areas makes it risky for thieves to do something fishy. Doing so also makes your vehicle visible to bystanders.
It pays to double-check your doors and windows whenever you leave the vehicle. Ensure all the windows are pulled up and the doors are locked.
Thieves will always try to look for a spare key inside your car once they manage to break in. Keeping one in your glove box will make it easier for them to steal your ride.
Anti-theft systems can fail like any other component in your vehicle. The cause can be a simple dead key fob battery or a complicated electrical fault.
If your car won’t start because of a bad anti-theft system, you might need to pay a trip to the nearest repair shop or dealership, especially if the system is factory-installed.
Any information provided on this Website is for informational purposes only and is not intended to replace consultation with a professional mechanic. The accuracy and timeliness of the information may change from the time of publication.
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Hi I'm having trouble with my 2008: eclipse not starting. I jump stared a friend with my car, imy car spraked and died. It will not start.we put the computor on and cleared the codes and it started then after about 2 weeks it would not start. This time there is a fuse under the steering column I pulled it out reset it and the car started , I had to do that Everytime to get it started. Now it is locked down again. Does anybody know how I can fix this security problem . It's completely locked down and the kept pod lock works but the red light indicator just stays on it should blink. Please help.