The harnesses in the car are different. They have the automatic wiring and plugs made into them and the manual cars are lacking all of this. The 2 harnesses that contain all of the automatic wiring is the interior harness, Dash harness, and the engine harness. This contains all of the wiring circuit that the automatic uses. The topics in this article will contain 2 explanations for each item. One of the options will be if you have all of the harnesses. The other option will be if you are lacking the wiring.

The engine harness contains all of the wiring that goes from the interior harness to the transmission plugs. The interior harness covers everything else. The cluster does have a extension like sub harness as well.

Main article: OBD Port

One thing to note is grounding is important on this transmission. Without proper grounding static can build up where the converter goes into the transmission and the static discharges without proper grounding will eat away at the bushing.

This is a four wire square plug and is confusingly the same plug as the shift solenoid plug. The pulse generator wiring collects from the top passenger side and the rear passenger side of each of the pulse generators with a clear sleeve. You really only need these with the stock TCU.

There are two versions of this. Early style which is rectangle and was used for the first two years or so. The Late style was used from then on all the way through the 2G. This is the connector that you will run into most of the time. These connectors are actually available through Sheridan Engineering here.

This is a four wire square plug and is confusingly the same plug as the pulse generators. The solenoid wiring comes out on the front of the case and has a black sleeve. The wire colors are the same on 1G and 2G except for one wire. These connectors are actually available through Sheridan Engineering here

There are various ways of dealing with VSS sensors on autos. 1Gs are cable driven. Cable drive is required for the dash speedometer to work. There is a signal wire that goes from the cluster to the ECU and to the TCU to read speed. 2gs are fully electronic. The problem with 1g cable drives is sometimes the signal can be slightly dirty and there is somewhat of a delay or even some variance as the cable can twist tight. Chances are if you have a stand alone you will have issues with it reading the cable VSS signal. For that is a device that goes between the transmission and the cable and sends a signal. Its called the Terratrip Japanese Gearbox Probe or Brantz Tripmaster Japanese Gearbox Probe. Its a rally part and isnt sold in USA as of yet so its not easy to get. This is what you would need for stand alone to read the speed and you would just set it up like a 2g or Evo VSS and alter the calibration offset in the ECU until the speed reads correctly.

The factory transmission temperature probe is essentially just a switch like a non adjustable thermostat. It just turns on the A/T Temp light indicator on front dome light. Its not an actual temperature sensor and should not be used as such.

This is the dummy light that comes on at a specific temp and lights the AT Temp indicator in the dome light. This is 1G only. If 2G has this in the cluster im not sure of.

Main article: TCU

The shifter wiring is quite simple as there are only 2 things in this that need wiring. One is the overdrive on / off switch and the other is the light for under the top of the shifter where it says PRND2L. This bulb is a 1157 style bump with a flexible translucent green cap over it. The wires are green and green with red dot. The bulb wires go into the upper corners of the plug.

The overdrive on / off switch is 3 wires. One is yellow with a white stripe, one is black with a white stripe and one is yellow with a white stripe.

This switch just essentially changes the shift points in the TCU. When in Eco mode it will shift early. If you put it in power mode it completes a circuit to the TCU and the TCU changes to a secondary shift map with higher/more aggressive shift points. This button is in no way connected to the ECU nor does it change anything with the engine at all. In case it needs to be said, no it does not raise the boost.