Does not work by itself! Needs the ALDU1 or APU1 to work.

Works with pre-1995 GM ALDL ports. You need this to log data on your GM. Connects directly to AutoProm or ALDU1. Is used on most pre-1996 GM EFI cars.

Does NOT work by itself! Requires the ALDU1 or APU1 to actually interface to the PC!