Computer Tuning

The engine and transmission in my truck are controlled by an electronic module known as the PCM (powertrain control module). Since my engine and transmission are different than what the PCM was originally calibrated for, the unit needed to be recalibrated. I did the original "rough and dirty" calibration myself, but left the majority of the work to the fine folks at DJ's Car Care. The process begins using datalogging software, which collects operating paramaters such as RPM, active gear, air to fuel ratio, and the status of several other vehicle systems. With this data, the calibration in the PCM can be modified. Paramaters such as upshift/downshift speeds, spark avance, idle speeds, rev limiters, and literally thousands of other values can all be changed. In order to use this software, which runs on a laptop computer, I built a cable to link the truck's data port to the laptop's serial port. Then in order to recalibrate the truck's PCM, I use a chip programmer attached to the laptop. Here is what the link cable looks like:

Here is what the PCM's calibration chip looks like:

This is a screenshot of the datalogging software:
DataMaster

This is a screenshot of the tuning software:
TunerCat