Mercury2 TCU

Bulk orders are discounted. Please email sales@spitronics.co.za for more details.

The MERCURY2 Control Unit is designed to be a cost effective replacement for high tech Engine Control Units (ECU) and Transmission Control Units (TCU). It uses unique and easy features which are easy to install and tune. It is designed with the novice and professional installer in mind.
This universal South African made product that can easily be customized for various engines or transmissions. It can be used for many applications such as racing engines, vehicle conversions, custom built vehicles, replacement parts for production vehicles etc. It is a compact reliable system which is epoxy filled to make it rugged and water tight for harsh environments and easy to mount in the driver’s compartment.
The Mercury2 unit is designed to connect directly to most sensors and drive units that is found on engines and transmissions. No need to modify them. It consist of the latest in high speed micro controllers with surface mount technology. These units are machine soldered to minimize human error.
The Mercury2 cover features like Lambda control, idle control, launch control, fuel pressure control, cam control, line pressure control, tiptronic gear control, stepper motor control and lots more. It has 8 positive drivers that can be converted to 12 coil igniter drivers for V12 engines. It has 8 negative injector drivers that can do full sequential injection for V8 engines and semi-sequential for V12 engines. 4 Negative drivers for GP outputs, rpm output, relay and electronic relay outputs. These drivers are ranging from 3.5 Amp to 6 Amp.
There are 9 analog input signals to measure water, air or oil temperature, throttle position, manifold pressure, lambda, fuel pressure, altitude etc. Then there are 4 trigger inputs to measure crank, cam & prop shaft angles.
The software is user-friendly and makes all the above features customizable by the tuner. This makes the Mercury2 adaptable for most engines and transmissions. Activations of features can be done over the internet making the unit viable to keep in stock and customize on demand.
This Mercury2 was designed to be universal and adaptable. Some firmware are customized to suit customers. New applications can easily be incorporated. Upgrades can be done over the internet.
To learn more about this amazing package browse through the features and specifications in the sub folders.

Note that some features are in the process to be developed in the future. The hardware has the capability for it. Also note that not all of the features may be included on the same ECU as there is limited amount of drivers available. Some of the hardware classes may not include certain features due to the price range. See the selection chart for the ability of the different classes.

Tiptronic or Paddle shift
· Automatic Mode – the driver sets the maximum target gear allowed.
· Semi-Automatic Mode – the driver has more manipulation of the gears with the added automatic features.
· Manual Mode – the driver has complete control over the transmission with the added protection against over revving.

Tune or Map Selection Switch – lets the driver set up his transmission in 4 different profiles like Automatic, Tiptronic, Towing, Off-road, Racing etc.

Shifter Position input
· The TCU can sense all kinds of shifter sensors to operate correctly in all lever positions. Different sensing boards could be connected to sense serial or parallel switches. Also switches with common Positive or Negative could be connected with the Level Shifter board.
· If no shifter sensor is available then the reverse light signal can be used to lockout shifting in reverse.

Gear Profile Adjustments – Each gear can be separately manipulated to shift up or down when the tuner requires it. These settings work on RPM, Speed and TPS values.

Line Pressure Adjustments – These pressures can be adjusted on a graph with the TPS representing engine load. There may be a number of graphs according to the transmission requirement. The software cater for 3 different graphs.

Indication LED’s – The TCU has up to 6 dashboard LED’s to indicate different functions that is selected. This will help the driver to manage his transmission.

· TPS sensor will indicate to the TCU what the driver’s intention is. Shifting can be adjusted accordingly.
· RPM signal will be used to shift the transmission to harness the engine power correctly and be economical.
· Speed sensor will be used as protection against down gear over revving and also other shift algorithms.
· Transmission Oil Temperature sensor will change line pressures during cold conditions to soften gear shifts.
· Low range sensor will adjust speed settings in the transmission automatically.
· Shifter Sensor indicates which position the lever is selected. this will indicate the TCU which gear selections are allowed.
· Tune Map Sensor will adjust shifting behavior according to selections by the driver.
· Sensors can be calibrated to suit most engines and transmissions.

· Shift solenoids will manipulate the required gear to be selected
· Duty control solenoids will control line, lockup and shift control solenoids to make the transmission as comfortable to the driver as possible.

General Purpose outputs – These outputs can be used for custom features like speed warning, sirens etc.

Speedo output – this signal drives speedometers and can be calibrated in the software.

Selectable Lockup – can switch on in all gears if transmission permits to improve economy and reduce heat.

Standard Harness – No need to keep several harnesses in stock for different engines. Level 2 harnesses will include relays and fuses that will ease installation and save time. All the input wiring harnesses use screened cables for neatness of installation and to prevent electromagnetic interference which may cause erratic behavior of the TCU. There are a few add-on boards to ease between different transmission wiring options.

Compact Electronics – This will make the TCU easy to hide under the dashboard as it takes very little space.

Complete firmware for Most transmissions.

Cost Effective – No need to buy expensive systems as all the necessary features are included with the TCU.

Standard Tuning Software – All the products use the same software. The features that is not used or allowed in the firmware will be blanked out.

Easy DIY Instructions – Save money on installation if you are a person who is up to the challenge.

Start-Up Maps included – This will make for easy start-up & tuning.

User Friendly -Tuning Software which is extensively explained in the manual.

Tuning map -can be locked to prevent tampering. Useful for transmissions builders to give guarantees.

No Dyno Required – Tune your own transmissions and save some money. Just follow the instructions in the manual carefully.

(Note that the last five points are for the person who is handy with tools and understand wiring and operation of transmissions. If you are not sure, download the software, Map, manual and drawing and experiment with it first. It’s free of charge!)

Power Supply

12V Ignition power 200mA, filtered by reverse polarity Diode, 700mA Poly switch and 25V Tranzorb

12V Relay power 14A Max, filtered by reverse polarity Diode

2.5mm2 Earth Strap


4x Trigger inputs – Magnetic Isolated (2 Inputs require a 1K pull-up resistor for Hall or Optic inputs)

5x Analogue input 0 – 5V

1x 2K NTC Temperature Sensor Input

1x 10K NTC Temperature Sensor Input

1x Lambda Input 0 – 1 V or Processed 0 – 5V signal.

Software UART Connection via USB2 converter cable

Firmware Programmer Connection


8x 6A P Channel Mossfets 12V output Floating, Over-current protected

8x 6A N Channel Mossfets Ground output Floating, Over-current protected

1x Mechanical Relay 3.5A Ground Output Floating, Over-current protected

1x RPM 3.5A Ground Output Floating with 1K pull-up resistor to 12V, Over-current protected

2x General Purpose 3.5A Ground Output Floating, Over-current protected

5V 600mA Power Output for TPS & Map Sensor

Electronic Relay 5V 5mA output for Spitronics custom 45A solid state relay


Size 145mm x 68mm x 21mm

Weight 240g

4 x Connector Type Plastic Molex 12, 10, 8, 6

1 x Comms Connector Type Plastic Molex 6

Load Sites ECU

Tuning Pallet load sites Resolution Adjustment Adjustment
Resolution Range
Fuel Vacuum Graph 64 Auto Range 0.1 ms 0 to 25 ms Interpolated
5 x Fuel RPM Graph 32 Auto Range 1% -50% to 50%
Micro Fuel Vacuum Graph 32 Auto Range 0.1 ms 0 to 25 ms Interpolated
Dynamic Timing Graph 150 100 RPM 0° to 45° Interpolated
2 x Vacuum Timing Graph 32 Auto Range -15° to 25° Interpolated
Trailing Degrees Graph 30 500 RPM 0° to 45° Interpolated
Water Temperature Timing Graph 18 -40° to 140° -50° to 100° Interpolated
Water Temperature Fuel Graph 18 -40° to 140° 1% -50% to 100% Interpolated
Air Temperature Timing Graph 18 -40° to 140° -50° to 100° Interpolated
Air Temperature Fuel Graph 18 -40° to 140° 1% -50% to 100% Interpolated
Lambda MAP Graph 24 Auto Range 1% -50% to 50% Interpolated
Lambda RPM Graph 24 Auto Range 1% -50% to 50% Interpolated
Injection Degrees Graph * 30 Firmware Firmware 0° to 720° Interpolated
TPS Fuel Graph 20 0% to 100% 1% -50% to 50% Interpolated
Fuel Matrix 16×16 Auto Range 0.1 ms 0 to 25 ms Interpolated
Timing Matrix 16×16 Auto Range 0° to 45° Interpolated
Cam1 Matrix * 8×8 Firmware Firmware Firmware Interpolated
Cam1 Matrix * 8×8 Firmware Firmware Firmware Interpolated
Fuel Pressure Set point Graph 12 Auto Range 0.1 Bar 0 to 7 Bar Interpolated
Fuel Pressure Correction Graph 30 Auto Range 1% -50% to 50% Interpolated
Battery Fuel Graph 20 0.5V 1% -50% to 50% Interpolated
Battery Charge Time Graph 20 0.5V 1% -50% to 50% Interpolated

* Not yet implemented

Load Sites TCU

Tuning Pallet load sites Resolution Adjustment Adjustment
Resolution Range
8x Gear Profiles Upshift 3 Auto Range 1% 0 to 100% Interpolated
8x Gear Profiles Downshift 3 Auto Range 1% 0 to 100% Interpolated
8x Gear Profiles Lockup 2 Auto Range 1% 0 to 100% Interpolated
3 x Duty Control Graph 50 100 % TPS 1% 0 to 100% Interpolated
2 x Oil Temperature Graph 15 -40° to 140° 1% -50% to 50% Interpolated

The Mercury2 is sold in six hardware classes categorized by the features required for each engine or transmission. The advantage is that basic applications is sold cheaper than more complex applications. These features can be activated or changed over the internet which eliminates time lost and courier costs. This makes it viable to have these units in stock at low entry cost and activate the features later when the project is started. The PC Tuning software is standard for all units. Certain features will be blanked out if it is not available. The firmware categories are Micro, Basic, Standard, Intermediate, Advance and Ultimate. On the ECU only 4 classes are implemented at this stage and on the TCU only 1 class. Please look at the following charts to see which hardware class will suit your application.

ECU Selection Chart

Mercury2 Hardware Standard Intermediate Advance Ultimate
Hardware Inputs
Map Sensor 1 1 1 1
TPS Sensor 1 1 1 1
Water Temp Sensor 2K NTC 1 1 1 1
Air Temp Sensor 10K NTC 1 1 1 1
Lambda 1 1 1 1
Altitude Sensor 1 1 1 1
Built In Altitude Sensor
Tuning Pot 1 1 1 1
Fuel Pressure Sensor 1 1
Dual Map Switch
Battery Volts 1 1 1 1
Power Management 1 1 1 1
Crank Trigger Pulse 1 1 1 1
TDC/Home Pulse 1 1 1 1
VVTI Cam 1 Pulse 1 Note 1
VVTI Cam 2 Pulse 1 Note 1
USB/Programmer 9Pin D-Sub 1 1 1 1
USB/Programmer 6Pin Molex
Hardware Outputs
Injector Drivers Negative Out 2 8 8 8
Internal Coil Drivers Negative Out
External Coil Triggers Positive Out 1 1 8 8
RPM Output 1 1 1 1
Electronic Relay Output 1 1 1 1
Relay Output 1 1 1 1
GP Outputs 2 2 2 2
Graph Tuning 1 1 1 1
Matrix Tuning 1 1 1 1
Idle Control 1 1 1 1 Note 2
Dual Maps 1 1 1 1
Micro Fueling or Fazed Injector 1 1 1 1
Full Sequential Injector Control 1 1 1
Fuel Pressure Control 1 1
V-Tech Cam Control 1 1 1 1
VVTI Cam Control X
Launch control 1 1 1 1
Anti-Lag control X X X X
Flat-Shift control X X X X
Boost control X
Throttle x Wire control X
RPM Calibration 1 1 1 1
Epoxy filed 1 1 1 1
Can be Epoxy filed
Note 1 – Only magnetic sensors – Requires external Pull-up Resistor for Hall or
Optic Sensors. Cam 2 input may be used for Dual Map selection.
Note 2 – For Stepper motors external hardware is required
X – Capable – Firmware not yet developed

TCU Selection Chart

Mercury2 Hardware Intermediate Notes
TPS Sensor 1
RPM Sensor 1 Note 1
Speed Sensor 1 Note 1
Oil Temp Sensor 1
Low Range Sensor 1
Shifter Selection Switch 1
Tuning Maps Selection Switch 1
Tiptronic Up Switch 1
Tiptronic Down Switch 1
GP Outputs 2
Solenoid Drivers Negative Out 8 Note 3
Solenoid Drivers Positive Out 8
Speedo Output 1
Electronic Relay Output 1
Relay Output 1
Battery Volts 1
Tiptronic Function 1
Quad Tuning Maps 1
Individual Gear Profiles 1
Duty Cycle Control 1
Speedo Calibration 1
Lockup Control 1
Lockup Selectable / Gear 1
Transfer Box Ratio Adjustments 1
Number of Gears Capable 8
Power Management 1 Note 5
Epoxy filed 1
Can be Epoxy filed
Note 1 – Only magnetic sensors directly – Requires an external Pull-up Resistor for Hall or Optic Sensors.
Note 3 – 2 drivers is used for Lockup and Function display LED’s
Note 5 – Hardware can keep itself powered after Ignition Off