What is Motronic?

At first sight, the Motronic control unit is an inconspicuous box of electronics. Its task is to adjust and optimize air and fuel injection, as well as the ignition process, to suite the driver's requirements. The technical benefits are impressive. Before Motronic was introduced 25 years ago, a mechanical construction was used to create the fuel-air mixture and produce an ignition spark. This resulted in high fuel consumption and high pollutant emissions.

Today, Motronic uses data from a multiplicity of sensors to calculate the best values for every injection and ignition process. This happens more than 6,000 times per minute. The core of the Motronic system is an electronic control device comprising a microprocessor and memory unit. A program with data for determination of the injection volumes and ignition times is saved in the memory. Sensors provide the microprocessor with information on the induced air volume, revolutions and engine temperature for every injection and ignition process. Motronic uses the information to ensure that the ideal amount of fuel-air mixture is always ignited at exactly the right moment.

The only wearing part in the Motronic system is the spark plug. Every Motronic system is therefore programmed to take the ageing vehicle components into account during their entire lifespan. Engines with Motronic live longer and need significantly less maintenance.

The beginnings

BMW was the first car manufacturer to introduce the new technology. In 1979, BMW equipped its 6-cylinder 732i with Motronic for the first time. It was a world premiere in several ways:

• The first digital engine control unit  
• The first freely programmable car engine control unit
• The first system combining injection and ignition

Motronic heralded the introduction of software into cars. It paved the way for other modern sub-systems: e.g. Automatic Slip Reduction (ASR) and the Electronic Stability Program (ESP).

Since then, Motronic has impressed by continuous further developments, cutting fuel consumption, ensuring even more precise control and using digital technology to enhance reliability.

Due to its technical superiority, Motronic was soon used in motor racing. The system was first introduced to Formula 1 in 1981. Two years later, Motronic won the World Championship with Nelson Piquet in his Brabham BT 52 BMW.

The present

Bosch pioneered the first Motronic 25 years ago. Today, only one engine management system is used by all major car manufacturers: Motronic. This year, Bosch is manufacturing 30,000 Motronic control units every day and will deliver the 75 millionth Motronic.

Especially the environment benefits from the system. All Motronics built to date have saved more than 575,000,000 tons of exhaust gas emissions in total. That is the equivalent of  7,500,000 large 75-ton railroad cars – a train so long, it would stretch more than twice around the world. With Motronic, average fuel consumption of European cars has fallen from 11 to 7 l/100 km. Some 50 million vehicles drive with Motronic today and save more than 30,000,000,000 liters of fuel every year - app. 60 supertankers full of gasoline!

Today, many functions can be integrated into Motronic to increase safety and comfort. They include cruise control units, knocking control systems, OBD self diagnosis, maximum speed limiters (for instance for driving with winter tires) and electronic starter inhibitors. Security systems such as Automatic Slip Reduction (ASR) and the Electronic Stability Program (ESP) can intervene in engine management to increase active driving safety.

A single electronic component has therefore revolutionized the construction of engines and vehicles during the last 25 years.

The future

Motronic is nowhere near the end of its potential. It can be used in diesel, spark-ignition, gas and fuel cell engines, and even in hybrid vehicles. In future, Motronic will also automatically detect defective functions and report them to the repair garage.
In addition, Bosch aims to offer drivers individual setting options within the Motronic device. They include regular software updates that allow buyers to individualize their cars even further.
With these innovations, Bosch abides by the ideals which inspired the technology 25 years ago: economic engines with ever lower toxic emissions, ever greater driving pleasure and ever increasing safety.