Nissan Anti Theft System Car Won't Start

The Nissan Anti-Theft System (NATS), also known as Nissan Vehicle Immobilizer System (NVIS), is designed to prevent unauthorized vehicle use. However, it can sometimes malfunction, leaving you stranded with a car that won't start. This article provides practical troubleshooting steps, maintenance tips, and real-world solutions for dealing with a Nissan that won't start due to the anti-theft system.

Understanding the Nissan Anti-Theft System

The NATS/NVIS system works by verifying the identity of the key being used to start the car. A microchip embedded in the key transmits a unique code to the vehicle's immobilizer control unit. If the code matches the one stored in the system's memory, the engine is allowed to start. If there's a mismatch or communication problem, the system prevents the engine from running, activating the anti-theft feature.

Common Symptoms of a Nissan Anti-Theft System Issue

Recognizing the symptoms early can help you pinpoint the problem quickly. Here are some typical signs:

• The engine cranks but fails to start.
• The security indicator light (usually a car with a key symbol) on the dashboard flashes or remains illuminated even after inserting the key.
• The car starts and then immediately dies (typically after 1-2 seconds).
• No crank, no start – the engine doesn't even attempt to turn over.

Troubleshooting Steps When Your Nissan Won't Start

Before calling a mechanic, try these troubleshooting steps:

1. Check the Key

Problem: The key itself may be damaged or the transponder chip might be malfunctioning.

Solution:

• Try using a spare key. If the spare key works, the original key is likely the problem.
• Visually inspect the key for any damage, especially to the plastic casing where the transponder chip is located.
• If you suspect damage to the chip, consult a locksmith or a Nissan dealership for key reprogramming or replacement.

Example: On a Nissan Altima, a cracked key fob can easily damage the transponder chip inside, preventing the car from starting.

2. Check the Battery

Problem: A weak or dead battery can sometimes cause the anti-theft system to malfunction.

Solution:

• Test the battery voltage with a multimeter. It should read around 12.6 volts when the engine is off.
• Try jump-starting the car. If it starts after a jump start, the battery needs to be charged or replaced.
• Check the battery terminals for corrosion and clean them thoroughly.

Example: A Nissan Rogue experiencing intermittent starting problems might have a corroded battery terminal causing voltage drops that trigger the NATS.

3. Check the Fuses

Problem: A blown fuse in the anti-theft system or immobilizer circuit can prevent the car from starting.

Solution:

• Consult your owner's manual to locate the fuses related to the anti-theft system and immobilizer.
• Visually inspect the fuses for any signs of damage (broken filament).
• Use a fuse tester to confirm if a fuse is blown.
• Replace any blown fuses with ones of the correct amperage.

Example: The anti-theft system fuse on a Nissan Sentra is often located in the interior fuse box. A blown fuse here could disable the starting circuit.

4. Reset the Anti-Theft System (If Possible)

Problem: Sometimes, the anti-theft system can become "locked" or activated unnecessarily.

Solution:

• Consult your owner's manual for specific reset procedures. Some Nissan models have a specific sequence involving turning the ignition key on and off a certain number of times.
• Disconnect the negative battery cable for 15-30 minutes to reset the car's computer. This may clear the anti-theft system. However, be aware that this might also reset other electronic settings in your car, such as radio presets.

Example: Older Nissan Maxima models sometimes require a specific ignition key cycling sequence to reset the NATS after a battery change.

5. Check the Immobilizer Antenna (Key Reader)

Problem: The immobilizer antenna, located around the ignition switch, reads the transponder chip in the key. If this antenna is damaged or disconnected, it can't read the key.

Solution:

Carefully inspect the area around the ignition switch for any loose connections or damage to the immobilizer antenna.

If you are comfortable doing so, you can remove the steering column covers to get a better view of the antenna. However, be cautious not to damage any wiring or components.

A faulty immobilizer antenna often requires professional diagnosis and replacement.

Example: In a Nissan Titan, the immobilizer antenna can be damaged if someone tries to force the ignition with a foreign object.

6. Seek Professional Help

Problem: If none of the above steps work, the issue is likely more complex and requires specialized equipment and knowledge.

Solution:

Consult a qualified mechanic or a Nissan dealership. They have diagnostic tools that can read fault codes stored in the car's computer and pinpoint the exact cause of the problem.

The mechanic can reprogram the key, diagnose immobilizer issues, or replace faulty components as needed.

Real-World Issues and Solutions

• Issue: Aftermarket alarm systems interfering with the NATS. Solution: Have the aftermarket alarm system properly installed or removed by a professional. Incompatible or poorly installed systems can cause conflicts.
• Issue: Water damage to the immobilizer control unit. Solution: Check for signs of water intrusion, especially after heavy rain. The immobilizer control unit is often located under the dashboard. If water damage is present, the unit needs to be replaced.
• Issue: Corrupted or lost immobilizer data due to a power surge. Solution: A mechanic will need to reprogram the immobilizer with the correct vehicle identification information.

Maintenance Tips to Prevent Anti-Theft System Issues

Preventive maintenance can help minimize the risk of anti-theft system problems:

• Keep your keys in good condition: Avoid dropping or damaging your keys, as this can damage the transponder chip.
• Maintain a healthy battery: Regular battery checks and replacements, as needed, can prevent voltage-related issues that can affect the anti-theft system.
• Avoid aftermarket modifications: Be cautious when installing aftermarket alarm systems or other electronic devices, as they can sometimes interfere with the NATS. Choose reputable installers and ensure compatibility.
• Address electrical problems promptly: If you notice any electrical issues in your car, such as flickering lights or a weak starter, have them addressed promptly to prevent further complications.
• Regular diagnostics: Periodic vehicle diagnostics can identify potential issues before they become major problems.

Specific Model Examples

Here are some model-specific examples of common NATS-related issues:

• Nissan Altima (2007-2012): Prone to immobilizer antenna failures, especially after a long period of use.
• Nissan Titan (2004-2015): Can experience issues with the key recognition system after battery replacements if the correct reprogramming procedure isn't followed.
• Nissan Sentra (2013-2019): Problems with the security indicator light remaining illuminated even with a working key. Often requires a system reset or replacement of the immobilizer control unit.
• Nissan Rogue (2014-2020): Issues with the smart key system not recognizing the key fob, especially if the fob battery is low.

Keeping Your Nissan in Top Condition

Maintaining your Nissan properly ensures its reliability and longevity. Regular maintenance, as outlined in your owner's manual, is crucial. This includes:

• Oil changes
• Fluid checks (coolant, brake fluid, power steering fluid)
• Tire rotations and pressure checks
• Brake inspections
• Air filter replacements
• Spark plug replacements (as needed)

By addressing maintenance needs promptly and taking proactive steps to prevent anti-theft system problems, you can keep your Nissan running smoothly and avoid the frustration of being stranded with a car that won't start.