18 Years of Honda VSA

Electronic stability control (ESC) is now a compulsory item for all passenger cars sold in the USA, Canada, European Union, Australia, New Zealand, Japan and Korea. Why? Because multiple research have concluded that ESC is the second most important safety feature after seat belts.

Research by universities from around the world - USA’s Insurance Institute for Highway Safety, Global NCAP, FIA, UN - all agree that ESC is the single most important safety innovation after Volvo’s Nils Bohlin invented the three-point seat belt in 1959 and shared it with the world for free.

NCAP bodies from around the world strongly recommend that consumers only purchase cars with ESC while the FIA’s stance is that “Buying a car without ESC is like buying a car without seat belts.”

Another important point that is often lost among car buyers is that ESC is far more important than the vehicle’s airbag count. This is because ESC prevents an accident from happening in the first place while airbags merely react to an accident and is only meant to minimize injuries.

This explains the firmer stance of NCAP bodies in placing greater emphasis on ESC over airbags.

Official records in Honda’s achieve say Honda was the first to introduce ESC to a front-wheel drive car in Japan - when it launched the sixth generation Accord (and its sister-car the Torneo) on 4-September 1997. At the same time, we have yet to uncover another front-wheel drive car, be it from Japan or anywhere else that had ESC earlier than September 1997. Do you know of any?

Mitsubishi had a simple side-slip control function in the traction control system of its 1990 Diamante, but it was not an ESC feature in a true sense as the system couldn’t take into consideration the vehicle’s yaw rate – a key input for ESCs.

The Accord referred to here is a Japanese-market Accord (also similar to the European-market Accord) and is not related to the global Accord that was sold in the USA and other parts of Asia. The Torneo is only available in Japan and is basically a Japanese-market Accord with a different front- and rear-end design.

In Japan, car manufacturers sell different models to different dealer networks. The Accord was exclusively available at Honda’s Clio (unrelated to the Renault hatchback) dealerships while the sportier Torneo was sold via the Verno and Primo dealerships.

While other manufacturers elected to purchase off-the-shelf solutions from automotive parts suppliers like Bosch or Continental, Honda took the harder path of developing its own ESC solution from scratch, hence the trademarked VSA (Vehicle Stabilty Assist) name.

On 2-July 1997, Honda announced to the world that it had successfully its own ESC solution, which will be branded as VSA. It was also revealed that VSA is a further development of Honda’s traction control system (TCS) which debuted in the flagship Honda Legend, which on 20-July 1989, became the first front-wheel drive car in the world to have TCS.

By combining the existing ABS (prevents wheels from locking up under hard braking, causing loss of steering control) and TCS (prevents wheel slip when accelerating away on slippery surfaces) with side slip control, VSA is able to prevent a skid caused by either understeer or oversteer.

There are four functions to Honda’s VSA – oversteer control, understeer control, standing start control, and brake control during cornering.

The on-board VSA-ECU is constantly calculating the data sent by the vehicle’s steering angle sensor, four wheel speed sensors, lateral acceleration sensor, yaw rate sensor and engine speed to determine if the driver is losing control of the vehicle or not.

If it is determined that the vehicle is about the go into a skid, the VSA-ECU will apply the appropriate measures to cut engine power, and brake either the inner or outer wheel to bring the vehicle under control again.

If it is determined that braking is applied while the car cornering at a high speed, VSA switches the ABS function from the usual 3-channel operating mode to a 4-channel mode. This is to allow the ABS to take into consideration of the vehicle’s weight transfer during cornering, allowing it to apply greater braking pressure on the wheel that has the most traction.

Today, VSA is available on all Honda models sold in Malaysia, though on some lower range models like the Jazz and City, it is only available in the more expensive E- and V-grade variants.

For higher range models like the Civic, HR-V, CR-V, Accord and Odyssey – VSA is a standard feature, which ideally, is how all cars should be specified.