The transmissions in a Fiero contain a gear-driven assembly that provides an electronic pulse used by the speedometer, Engine Control Module (computer), and ignition module. We do not have information on the speed sensor for the automatic transmission. The speed sensor for the manual transmission was common to the following vehicles, IF these vehicles also had manual transmissions:

For '85-88 Fiero

'86-87    Buick Skylark
'86-87    Buick Somerset
'88-89    Oldsmobile Cutlass Calais
'86       Pontiac 6000
'85-89    Pontiac Grand Am
'85-88    Pontiac Sunbird