electric power steering uses an electric motor to assist the steering. a computer module ( ECU ) receives information from several sensors and decides which level of assistance the electric motor should deliver to the steering. when you install an electric power steering set up to your vehicle it won´t work because the ECU doesn´t receive information from vehicle speed sensor and engine speed sensor. these aren't often fitted to the older vehicle .that’s why you need a steering controller unit. it sends the relivant information to the steering ECU without this an electric power steering system will not work.
here at easysteer we offer three types of steering control unit,all are very effective ,the variable and auto controller are what we fit 95% of the time, the variable is a small controller with a potentiometer that allows you to vary the steering weight (variable controller).
the auto conrtoller will constantly analyse the force applied at the steering wheel by the driver and automatically adjust the steering assistance level,if the driver is applying some force at the steering wheel (for example when parking) the steering will automatically give the maximum assistance. If a driver is on motorway they will apply a small force at the steering wheel and the steering will automatically turn OFF, allowing the driver to have a very precise steering at higher speeds, included is a LED.the installation of the LED is optional,the LED indicates to the driver the level of assistance on each moment. There are 5 steering assistance levels (auto controller)
speed sensitive controller can convert your vehicles existing speed pulses into a signal that the steering ECU expects to see. this gives the steering ECU the ability to run different assistant levels depending on the vehicle speed, as it was designed to , and all the changes in steering assistance are done seemlessly
low mph - High Power Assistance
medium mph - Medium Power Assistance
high mph - Low Power Assistance or switched off
to do this the Speed Unit needs a 5 to 12V pulse from your speed sensor, so it would need either a proximity sensor, or a hall sensor that detects a bolt, toothed wheel, etc. if you have a VR sensor (abs style) then this needs converting to a 12V pulse before it can feed the steering controller unit (speed sensitive)
all cars/van/buses differ in what is needed, there are a lot of variables to consider
weight of car on steering axle
steering rack ratio
tyre width and compound
steering wheel size
we can advise on which control unit would best suit your needs, but sometimes its better to try both and make a final choice , once your power steering set up is all on and working , the control boxes can be swapped in minutes