Over the last few years there have been a few reports of cars getting away on their drivers, also known as ‘unintended acceleration’. There have also been some high-profile overseas recalls in the past as a result. It is very much a ‘thing’ and aside from a vehicle fault there are some real external influences that can cause this.
The accelerator pedal is a pretty important feature of the car as without it, you’re going nowhere fast. Traditionally a cable was used to connect the pedal to the engine throttle control. Nowadays the cable is out and fly-by-wire is in. This system uses an electrical potentiometer on the pedal to activate a motor attached to the throttle flap. A downside to this system is that on some vehicles the pedal had lost the direct feeling of actually opening a throttle valve, and you could beat the system by pushing the pedal down faster than the vehicle was willing to respond when hard acceleration was demanded.
A vast majority of automotive technicians would have received complaints of a brake pedal being hard to depress or the vehicle not accelerating like it used to, only to look inside the vehicle and see layer upon layer of carpet or mats wedged under the pedals making it impossible for the pedals to reach full travel.
This can also work in reverse for the accelerator pedal and does not need to be because of layers of mats either. Most cars with factory mats will have them fastened at one end and specifically designed with cut-outs to keep the mat away from the pedals. This is a good step to stop them sliding around and certainly something to look out for when fitting aftermarket mats. Make sure they are secure and there is no way then can reach the pedal area under any circumstances.
We spoke to an AA Member recently who experienced this very scenario. His factory floor mats had been stretched by his feet and jammed the accelerator while driving down an Auckland motorway. Fortunately he was prepared and was subsequently able to avoid a collision. He simply turned the key off and coasted to a stop on the verge and called for a tow. The vehicle was inspected with a fine-toothed comb and it was determined that his mat had aged and become pliable over time which allowed it to reach his pedal area. While the chances of this happening are small, being prepared can save lives.
To reiterate the importance, there was an instance in 2009 where a family of four lost their lives when their vehicle accelerated out of control on a highway in California, as a direct result of a mat getting stuck around accelerator pedal.
If you do happen to find your car accelerating beyond your control, here are a few steps that could prevent a similar scenario unfolding.
1. Press the brake pedal... Hard
The engine will be racing and any brake assist features may become redundant but the brakes are more powerful than the engine and will slow the car, eventually.
2. Select neutral
In neutral, the engine revs will hit the limiter, but at least the drive will be disengaged from the wheels and the vehicle’s speed won’t get any faster. Most transmissions can easily shift from drive to neutral.
3. Turn off the car
Turn the key off to the ACC position, or hold the start/stop button to shut the engine down. Now you’re in control of the vehicle, think about stopping in a safe place away from traffic. Be prepared for the steering to become stiff and the brake pedal hard as the assist functions will become unavailable. Remember to activate those hazard lights to let others know something is going on. In this instance the exact cause of the unintended acceleration may not be known, so it’s best to call for roadservice to have a look or organise a tow to a workshop for further investigation.
It’s not just the mats to look out for. Ensure that other items around the driver are secured. This means phones, drinks and wallets should be stowed securely to stop them from falling into your lap or floor as you travel. Not only is this a distraction, it can get in the way of the brake pedal.
And in summer, we love to wear jandals and other loose fitting footwear, but they are not safe for driving as they can slip off your feet and get under the pedals. It’s best to remove these before you drive and stow them away from the driver’s area. In fact, close-fitting shoes are ultimately the best for driving.