This document guides you to put a working product together from scratch. It will link you to the sections in the manual that your application requires, and how to set the product up correctly and print the relevant drawings for that installation. This legwork will save you or your customer time and eliminate lots of support calls. As this is a DIY product, the dealer must do this for his customer. If you carry stock, then you will do it when the customer requests a specific system.

Selecting a Product

There are 2 Spitronics TCU products currently in production namely Orion and Mercury2. Each one has Pro’s and Con’s and it is wise to take time out to know the differences. Selecting the wrong one may affect the price or the features that is required. Each TCU has its own manual and the Product Selection of its manual is the section to read for this information. You may also look at the TCU Comparison Chart and TCU How to Choose section. Note that these documents are the same for both manuals.

Choosing Firmware

After you have decided on the product type then read this section in that products manual. If you are choosing Mercury2, then you are in the right place.

Now you will need Transmission Information from the customer to decide which firmware must be used. Firmware are developed according to the transmission model number. TCU does not have modular drawings and are specific for each application. However, the customer does have the possibility to combine other shifters and components with this product. In these cases, he may look into the description for general drawings as guidelines. This will be connections like TPS, RPM, Shifter, Tiptronic Buttons , Map Selection Switch and Speed sensor .

Now you can view the Program Number Chart and see if firmware exists for that product. Mercury2 does not have the amount of inputs and outputs that Mercury2 has so it may be that it is impossible to run certain transmissions.

In the Program Number Chart, you will find the Firmware Features according to its hardware class and the GP Priority Layout for that specific firmware. Mercury2 TCU Selection section will explain this chart and how to get the relevant information from it. With this information you know if firmware exists and what hardware class is required as well as how the TCU connections are laid out for that firmware. Remember different firmware versions will have different connections to the TCU.

Example of Firmware Features 7

Example of GP Priority Layout Adv / Int

To program the Mercury2 ECU see the Firmware Programmer section.

Printing documents

If you have a Model number for the transmission then you go to Transmission drawings and look in the sub folders for that transmission. Here you will find all the relevant information that you require.

Installers prefer drawings on paper as they can make notes on customising and different wire colours etc. Also mark what is not used and what is already done. Note that this document only guides you to connections on the transmission that we have found. There may be other versions of the same transmission on other vehicles. For that you will have to consult the Service manuals and please forward variations to us for updating the current documentation.

For Explanation we use the Aisin A343E transmission. If you look at the information on the sheet you will find the following.

Main Drawing

This will open the full wiring diagram of the transmission with its standard connections. Note that ECU application and Stand Alone application use a different harness hence the two drawings. You will see the drawing has 2 pages so you need to scroll down inside for the other half.

Use with ECU withMTWX02/2 Harness

Aisin A343E Drawing

Use as Stand Alone with MTSX02/2 Harness

Aisin A343E Stand Alone Drawing

Default Harnesses

These links will take you to the design drawings of each harness. If you do manufacture your own harnesses do make sure that you comply to wire thickness and screened wires.

MTWX02-2 Harness (ECU Connections)

MTSX02-2 Harness (Stand Alone System)

Diode Board.

The TCU applications require external diodes to prevent spikes or interference from the pulsing inductive loads. These boards com in positive or negative configuration. They are built into the harness and sealed properly with silicon and heart shrink to prevent water damage. If you don’t have these boards there is a schematic on how to connect normal diodes onto the solenoids. They are not always built in due to the number of connection options for different transmissions.

DB1 Positive Diode Board

A343E Freewheel Diode Schematic

Shifter Converter Board

This board is required for digital switches in the shifter so that only one input on the TCU is required. They come in 2 varieties’ namely Serial and Parallel Digital to Analog converters.

CON2 Serial A/D Converter

GP Priority Layout

This link will take you to a connection sheet that indicates where each wire must be connected for that firmware as well as the wire color.

Aisin A343E 4Speed Connection Layout (Pdf)

Hardware Class Comparison

This will compare the features of the different classes as well as Mercury2.

Aisin A343E

Tyre Calculator

This helps to set up a starting map for the customer.

Tyre Calculator Aisin A343E (Excel)

Packing List

This guides dealers and customers to see which items is required for this application.

Mercury2 Aisin A343E Packing List (Excel)

Old Harness Layout

This is not recommended for Mercury2 but merely for backwards compatibility explanations. Some are discontinued.

RPM and Speed Sensors comes in different types and connections. Do note that these connections differ for different harnesses for. Use the correct harness link to view the data and print it for the customer. There are 2 main groups for transmission connections. A harness to use with an ECU product or a harness to use as a standalone product like for a diesel or carburetted engine. The main difference is that RPM and TPS sensor connections have long screened wires that go to the engine bay end connects on custom sensors. Also note if you are tapping into a system you may need a filter to eliminate interference.

Other drawings you may need are TPS, RPM, Shifter, Tiptronic Buttons , Speed sensor, Map Selection, Oil Temperature , General Purpose Outputs and Speedometer.

Precautions and Installing
Before attempting to start an install it will be wise to read the Precautions for Mercury2. This section outlines general wiring mistakes customers make that will cause operation problems like interference later.

Start-up
When you start an transmission for the first time do follow the Start-Up Procedure for Mercury2. This will take you step by step through the process of checking everything. In some cases, you may damage a unit if your setup in the software does not match your wiring on the transmission.