In the centre of the original pedal assembly is a small metal piece that is integrated into the brake pedal linkage. It is the brake pedal retraction system, which is designed to prevent the pedal from causing injury to the driver in a frontal impact. This mechanism was only fitted to cars in the UK, Ireland, Australia and New Zealand, where safety regulations necessitated it.
When a significant force – which should be above that used in emergency braking – is applied, this component in the pedal assembly detaches from its mounting. This causes the brake pedal to drop away, preventing an impact with the driver’s legs. Similarly, if the bulkhead begins to deform in a collision, the link can detach, again causing the pedal to retract safely.
It transpires that the design of the original part resulted in an overly sensitive safety system, one that could leave a driver with no brakes at all. The revised pedal assembly, on the other hand, has a much thicker and differently structured brake pedal retraction link.
“I was surprised to hear of this phenomenon,” said Suzuki. “We had not encountered it before. We had submitted the cars to a lot of testing but nothing had happened.
“On the Saturday, I had a call from the office. Then we immediately started investigations. Within 24 hours, we had reproduced the problem Autocar experienced and had started making changes. It was discovered that a few links were bending when they should not.
“A big, sudden force through the pedal could cause the link part to bend and prematurely detach as a result. We then set about designing, making and checking new parts. We then brought them to the UK to test them and make sure they conform.”
Suzuki gestured to the revised Celerio sitting at the start of the mile straight, and I took a seat. Instead of chancing my arm, this time around I carried out a static test on the parked Suzuki. Stamping on the brake pedal repeatedly did nothing except exhaust the available vacuum assistance – the engine wasn’t running – and the pedal steadfastly refused to do anything unexpected.
We headed out onto the track, wound the Celerio up to 60mph and stood on the brakes. The ABS chuntered, the tyres chirped and the car came to a halt. The stop was controlled, effective and exactly as it should have been. I stretched the Celerio to 80mph and repeated the emergency stop. The process was repeated several times, but the
brake pedal behaved exactly as it should have. It seemed clear that the issue had been resolved.
From the first failure to our test of Suzuki’s remedy, 10 days had elapsed. Crucially, no customers had been in a position to suffer a failure like that experienced during our controlled tests. The cars that were recalled are now in the process of being fitted with the modified components and returned to the customers, and the Celerio is back on sale.
“We were lucky,” said Suzuki as
we prepared to depart – not words you generally expect to hear from
an engineer, even less so one working for a mainstream car manufacturer. “We have a lot of ground to get back, but we have experienced a lot of support from our customers. If you had not tested this car, which was almost on the market, we would have had some troubles.”
Blog: Once it went wrong, Suzuki got it right
A manufacturer's prompt response is of the utmost importance in situations like this. The sooner the customers are informed, the cars are off the road and the inspections and revisions made, the better. For a company to leave the customers to find out about a potential failure the hard way is simply unacceptable, particularly if it’s one that’s easily demonstrated and identified.