Spitronics TCU Standard Manual page 3

1. SPITRONICS TCU Introduction
The SPITRONICS TCU is an aftermarket Automatic Transmission Control Unit which is designed
to customize shifting and control of many different transmissions. The requirement for this
computer arises mainly for the following reasons. Where existing computers failed and spares are
scarce or none is existing. When modifications to vehicles are done and existing TCU's do not
shift correctly. For racing and recreational vehicles which must be customized. It is used as a cost
effective replacement for existing TCU's.
SPITRONICS TCU is a South African made product and can be customized for dedicated
Transmissions and models. It is a reliable compact system which is easy to mount in the driver's
compartment. No external modules or converter boards are necessary.
The TCU is customized for specific applications and the installer does not have to pay for excess
wires or unused features. Nor does he have to buy separate modules and sensors which will
increase the price. Instead it is compiled with the correct harness and equipment as well as
software and profiles to ease installation and setup. The software will also be calibrated for the
sensors of the specific Transmission.
To make this TCU really versatile it comes with hardware electronics, firmware for the hardware
which is specific to each model of TCU and the powerful user friendly PC Tuning Software.
Hardware
The electronics is designed with inputs to read the sensors and then outputs to control the
solenoids in the transmission. It also has a user interface to select different profiles and operating
features. The main operation required for the transmission is to control the shift solenoids which
activate different gears and then the pressure solenoids which smooth shifting and protect the
clutches in the transmission. It also controls the Torque Converter Clutch to reduce fuel
consumption. In some cases there are features like 4x4 or diff lock selection, reverse block out,
smooth shifting solenoids and lockup clutch pressure control to name a few. The hardware also
consists of two type's namely common positive and common negative solenoid wiring. This means
that some transmissions require 12 volt and other ground to control these solenoids.
Firmware
This part is not really the concern of the user but it is the operating system of the hardware
electronics. It is custom developed for each type of transmission and is essential for correct
operation and shifting. This firmware is tuned and set up from the PC software to operate the
transmission as it is required by its manufacturer. Once the tuning software is disconnected, this
firmware will take over on its own and control the transmission from there on.
Tuning Software
This software let the user customize the operation of transmission to work exactly as he prefers
the shifting process. The tuner can determines at which RPM's and speed certain gear changes
must take place. There are also line pressures to control. Then the tuner can select up to four
different profile profiles which can be selected in the vehicle with a rotary switch. These profiles
can be set up for automatic, Tiptronic, towing, off-road driving and low range driving. It is totally up
to the customer and his requirements for his vehicle.