By installing an electronic control system designed specifically for spark-ignition engines, a vehicle can be upgraded from Euro 1 to Euro 2. This can save the car owner a considerable amount of money on road tax (Germany specific), while at the same time increasing the resale value of the vehicle.
The electronically controlled system functions in the following manner: immediately after the engine is started, the system temporarily raises the idle running speed of the engine, so that the catalytic converter reaches its normal operating temperature quicker and the output of pollutant emissions is reduced significantly.

The benefits are obvious

  • Better emissions classification (from Euro 1 to Euro 2)
  • Lower road tax (Germany specific)
  • Higher re-sale value

In addition to the system, all installation materials and documentation required are included in the scope of delivery. This includes the form for submitting to the vehicle licensing agency when applying for tax band reclassification (depending on the country in which the vehicle is registered) and the national type approval certificate.

HJS gives a 3-year, 100,000-km (60,000-mile) warranty on its EURO TR2 systems – whichever occurs first.

Technology & how it works

As of an engine coolant temperature (on starting the engine) of 5 to 12°C, the EURO TR2 control unit regulates the engine starting speed to 1100 to 1700 revs per minute. This slightly higher idling speed heats up the catalytic converter quicker, so that it reaches its optimum operating temperature sooner. As a result, it is able to "clean" the exhaust emissions more effectively after just a short time on the road and the vehicle can be reclassified from emissions class Euro 1 to class Euro 2 and benefit from a lower rate of road tax.

As soon as the engine coolant reaches a temperature of 34°C, the EURO TR2 system switches off and the idling speed returns to its normal level. This also happens if the driver drives off immediately after starting the engine and the engine speed is higher than the value controlled by the EURO TR2 system.

EURO TR2 is an intelligent idling speed control system that always cedes absolute priority to what the driver is doing. The system is incapable of having any form of negative influence on how the vehicle drives.


The EURO TR2 electronic control unit is installed in the engine compartment and connected to the car's engine management system by means of a cable harness supplied with the ECU. The temperature sensor is installed in the coolant circuit, while the power supply and engine speed data are picked up by connecting the control unit to the ignition coil. There is no need to disassemble any components of the fuel injection system.

System test

Once the electronic EURO TR2 system has been installed, it can be tested with the aid of the test plug (the jumper supplied) of the EURO TR2 cable harness' temperature sensor connector.The test plug trips diagnosis mode in the control unit and the engine speed is increased to a defined test speed of 1100 – 1600 rpm irrespective of the coolant temperature.   |   |   |   |   |