Auto Control Tuning Guide

Intro

Tuning automatic transmission can be daunting at first, but as with tuning an engine, following the right sequence of events should simplify things and help ensure you don’t have any misshaps in the the process.

In this guide we will go over a method you should follow to get you moving, and out of the danger zone, so you can get on with the fine tuning, essentially the transmission version of roughing a tune in.

What this guide doesn’t do is give you details on each setting available in PCLink. Please make use of the inbuilt PCLink help file for details on each setting.

What you’ll need

It’s well worth your time to track down any information or service data for your specific transmission. This can help get a rough idea of what the factory tune may look like. Factory service manuals can be a wealth of information if you can track them down.

Examples of useful data you might want are:

• Which solenoids are switched, and which are PWM

• Whether your solenoids are low or high side driven.

• PWM solenoid frequency

• How many teeth on your shaft speed sensors

• The stock shift tables

• Stock line pressure behavior

• Stock logic around things like torque converter lockup and accessories like 4WD solenoids.

Other aspects of the auto tune are hard coded into PCLink for you, such as behavior with shift solenoids and overrunning clutch solenoids for example.

It’s also worth familiarising yourself with how your transmission works in general, such as how line pressure is controlled and its effects on your tune, and just what the overrunning clutch solenoid is? Some of the control schemes are quite counter intuitive.

Before You Start Your Install

If you can not find material on the factory tune, and if your car is currently in a running state, we recommend you do some test drives to note down some of the factory behaviour before upgrading.

Make notes around the stock shifting points, note at which speeds up shifts are commanded at various throttle positions, and also at what throttle positions command a downshift at given speeds, to build a picture in your head of the stock shift table

Make a note of when the torque converter locks and unlocks

If you have a Link ECU already running your engine, but not the trans, you can install a line pressure sensor, and do some logs to see line pressure against your load and speed, and its behaviour when shifting, this data can be invaluable for dialing in smooth shifts later in the tuning process.

Tuning process steps

• Initial set up

  • Define the transmission being used.

  • Assign solenoids and sensors to their pins - and how they are controlled, high or low side, if switched or PWM and frequency/duty cycle if so etc.

  • Set up gear detection and ratios

  • Set up your first shift table

  • Set a baseline line pressure table

• Test drive

  • Verify gear detection

  • Test transmission going into gear, and changes gear

  • Setup gear normalise ratio

  • log and enter shift times

  • Max downshift RPM setup

• Fine tuning

  • Method for finding smooth shifting line pressures

  • Torque limiting and Shift cuts

  • Recalibrate shift times

  • Tune TC Lockup

• Examples

  • Example of different shift tables

  • Example of manualised shifting with range selector

  • Example of manual mode on any transmission

  • Example of a towing mode

  • Example of an offroad mode

List of current supported transmissions