Alarms and Immobilisers in Tyne and Wear

Alarms and immobilisers protect the car, and when they misbehave they can also stop you using it. A siren at three in the morning or a car that turns over but will not run is rarely a coincidence.

These systems link to the key, the central locking and the engine control, so a fault can sit in several places. We trace which part is involved before deciding what to repair.

Common symptoms

Security faults often start small. They are easy to put up with until the day the car refuses to start.

• The alarm sounds for no reason, often at night
• A security or key-shaped warning light stays lit or flashes
• The engine cranks but will not fire, or does not crank at all
• The key fob stops locking or unlocking the doors
• The car starts only on certain keys

What we check

We start with the simple things. A weak car battery can trigger false alarms and confuse the immobiliser, and a flat battery in the key fob can stop it communicating. Door, bonnet and boot switches that fail to register closed can also keep an alarm active.

If those are fine, we read the security system with diagnostic equipment and test the aerial, wiring and modules.

Alarm or immobiliser?

An alarm is a deterrent that sounds when something is disturbed. An immobiliser is different: it stops the engine starting unless the correct key is recognised. A fault in one does not always mean a fault in the other, though they often share wiring and modules.

At Banks of the Tyne in Hebburn we explain which part we think has failed. Some vehicles have security features that only the manufacturer's system can reset, so whether a particular fault can be dealt with depends on the vehicle. Ask us.

Before you come in

Bring every key you have, including spares, as comparing them helps. Tell us if the car was recently jump-started, had a new battery or had other electrical work, because these can set off security faults.

If you are fitting or changing an alarm and your insurer has requirements about security equipment, check them first so you do not end up with something that does not meet them.