EXCLUSIVE: UK: Toyota advances hill start assist technology with new Land Cruiser line
Toyota has moved ‘hill start assist’ technology on considerably with the launch of a new Land Cruiser line to replace the Colorado/Prado line.
Just-auto initially challenged Toyota’s claims that its “Hill Start Assist Control” (HAC) was an industry first, pointing out that Subaru had introduced a similar system called “Hill Holder” at least 20 years ago.
Subaru's Hill Holder system activates when the driver presses the brake pedal followed by the clutch and then releases a brake. A cable link from the clutch pedal activates a pressure hold valve that maintains pressure in the brake hydraulic circuit. A ball in the valve blocks a fluid passage back to the master cylinder under certain conditions, maintaining the brake pressure on hills.
But Toyota said that its HAC system was quite different.
“The engineers were fully aware of Subaru's system when we made our claims about Hill-start Assist Control,” said Toyota (GB) spokesman Scott Brownlee.
“There are key differences between the two systems that make us say that HAC is unique: - Subaru's system works only with a manual gearbox and is only activated when you press the clutch pedal and brake pedal.
“We presume the system's purpose is to help less experienced drivers with normal, everyday uphill starts.”
Brownlee said that the Subaru Hill Holder system activates the brake system to stop the car from rolling back.
However, he said that the Toyota HAC differs in a number of respects.
HAC is available with both manual and automatic gearboxes and is always activated whenever a forward gear is selected, the brake pedal is not pressed and the skid control electronic control unit has detected backward movement of the vehicle when the driver is starting off on a hill.
“If the system is on, then it will be activated every time these three conditions apply,” Brownlee said.
“The system was developed to help the driver to start the car on hills with slippery surfaces. This means that the braking operation is made in a smooth way by the four brake discs and not by the handbrake.
“Standard operation of the hydraulic brake operation wouldn't serve the purpose of the system.”