Recalibrating Speedometer on 1993 Camaro / Firebird Trans Am

Recalibrating Speedometer on 1993 Camaro / Firebird Trans Am

Unfortunately, recalibrating the speedometer on a 1993 F-Body (Camaro Firebird, Trans Am) cannot be done with tuning. For these cars we recommend a Dakota Digital SGI-5.  We offer these for sale on our website here.


Installing of one of these boxes is not very complicated.

  1. To start, remove the passenger side kick panel (where your right foot would sit against if you were sitting in the passenger seat).  Its held in by a few Philips screws and runs pretty much the entire length of the passenger door.
  2. Locate connector C220.  Find it by matching the appropriate colors in the image below.
  3. Tap into the gray wire going to pin F and wire it to the POWER pin on the SGI-5. This wire is your fuel pump feed wire and it is only hot for the first few seconds of key on or while the car is running.  If your fuel pump fuse pops the speedo will not work.
  4. Cut the Dark Green/White Tracer wire going to pin G. You may need to extend these wires. The wire going to back in the harness towards the grommet in the firewall goes to INPUT. The wire going towards the rest of the dash goes to OUTPUT 2.
  5. Run a wire from the ground lug shown in the image below to the GROUND pin on the SGI-5
  6. Install a 10K ohm resistor between the gray wire going to the POWER and the Dark Green/White Tracer wire going to INPUT.  See image below.  Without this resistor the box will not work. If you need one let us know when you purchase a SGI-5 from us and we will throw a couple in the box for you.
  7. All the switches will be set to OFF.  You will need to calibrate it by following the SGI-5’s instructions in application 2.


C220 Location



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