Immobilisers: if your car is not starting, you need to read this

It’s one of the wonders of modern car ownership. You can close your car miraculously from a distance, with a nonchalantclick of a button. Even when you forget to do this and leave your car open, it will still probably be safe due to the keys needing to be within a certain distance of the vehicle (if you have a fancy car) or, otherwise, thanks to the good old-fashioned immobiliser.

For anyone who isn’tau faitwith the technology, theimmobiliserworks together with the car’sEngine Control Unit (ECU)to check a unique code in the ignition with a code imprinted on the key. Without thiselectronic key system interlocking, the car will not be authorised to start.

But with technology this advanced, there will of course be drawbacks. Especially at this time of year, there will be dozens of drivers hearing that familiar turning over of the engine while they sit in the cold hoping for it to catch. All is not lost! Here we’ve exploredcommon immobiliser faults, and what you can do about them.

Damaged wiring can be a problem in an older car.Wiring can become corroded over time. The immobiliser usually has two relays: one is for the fuel pump and one is for the starter motor. The starter relay is the more likely to fail. To test this, try to check if the fuel pump is priming.

The next job will always be tocheck warning lights, but other signs may be subtler. If the engine is dead and won’t even turn over, or turning over but not starting, then it’s time to do somefurther diagnosis. If the lights are on but the engine is not turning over, then you can already rule out a flat battery.

Other simple tests can includetesting the keyswith another key for that model (a swap test’) or replacing the batteries in the key fob to ensure that this isn’t causing the problem. It could even be a battery issue, in which case testing another battery could be worth a try, to narrow down the cause of the issue.

If, after checking all the above, you still have a problem with your immobiliser, don’t hesitate togive us a callor contact usvia emailor chat. At Autotronics we can offergreat savings of up to 80% compared to main dealerships, depending on the service required. Our turnaround times are usually 1 to 4 days, from receiving the item to sending it back to you, and we offer international coverage.