Paul A. Romsky Jr. - Fiero GT ALDL Monitor

The following links are screen shots of the Assembly Line Diagnostic Link (ALDL) Diagnostic Tool that I am developing for Fiero owners (Free for Fiero Owners). Pontiac Fieros were built before On-Board Diagnostics I (OBD-I) and On-Board Diagnostics II (OBD-II) were standardized. General Motor's (GM's) predecessor to OBD was the ALDL which simply outputs a constant stream of parameters so that the vehicle's Electronic Control Module (ECM) could be used to test and monitor the vehicle before it left the factory. Today, it is very difficult to find ALDL scanners on the open market, and the fact that GM was never forth coming on how ALDL worked only exasperated the problem. Fortunately, I have found various web sites that describe how the ALDL protocol works, so I decided to try my hand at interpreting these unique data streams. The Fiero ALDL Monitor GUI is the first result of that effort.

Note: The Comms_Status LED is Red in these screen shots. That is because I did not have the ALDL Adapter connected to the PC when I took the screen shots. You can still use the Fiero ALDL Monitor GUI without an Adapter, but you can only playback files previously recorded and/or captured - until you connect an Adapter, then you can Monitor, Record, and Capture as well.

1987 Fiero GT ALDL Diganostic Tool - Lamp Test
1987 Fiero GT ALDL Diganostic Tool - Set-Up
1987 Fiero GT ALDL Diganostic Tool - Monitor/Record/Capture/Playback
1987 Fiero GT ALDL Diganostic Tool - Flags
1987 Fiero GT ALDL Diganostic Tool - Error Codes
1987 Fiero GT ALDL Diganostic Tool - Graph

01 SEP 2022 - Improved Version - Supports the new High Performance ALDL Adapter based on the Adafruit Trinket M0 Microcontroller.

Download the Fiero ALDL Monitor GUI V1.6.0

The Fiero ALDL Monitor software is free. It currently does not support the Serial ALDL Cables that are popular, you must use my special adapter - details on how to build one are included with the code download. If you are not confident to build your own adapter, I can build one for you at cost. Contact me at my e-mail adress for details.