GM 94-95: Reflash or not?

94 and 95 were also kind of odd years for GM computers as they transitioned toward OBD2.

There are several groups of ECMs.

94-95 LT1,LT4,LTx: These can be tuned via TunerCATS ( link ) with the $EE definition and an ALDU1+CABL1 (94 – square ALDL style connector) or ALDU1+CABL2 (95 “D” shape OBD2 connector).  These are typically the 16188051 ECM.  APU1 also works for reflash on these vehicles.  No chip adapter needed.

94-95 TBI: Unlike all other TBI ECMs (which use a G2 chip adapter) these ECMs are memcal like their TPI cousins and work with the G1 memcal adapter.  Take the cover off the ECM and if you see a memcal, you probably have one of these.  The 16168625 is an example.

94-95 W-body LQ1: uses the regular MEMCAL found in 1227165/7727/7730 ECMs, you can use the G1 adapter in these units also.

94-95 3800: Primarily use the 16183247 and subsequently a different style memcal is used than earlier ECMs.   The 94-95 3800 powered regals use a similar ECM that is weatherproofed, the 16183428, but that ECM is specific to the 94-95 3800 Regals only. This family of PCMs have the little blue ‘box’ memcal that has the integrated knock sensing board.   A G4 chip adapter is required for these, it’s shorter than the G1.

93-95 3100 vehicles (except for the A-bodies, which use a non-weatherproof version of the 94-95 LQ1 PCM) are all flash units. Unfortunately we don’t currently have a solution for these.

(Thanks to Robert Saar for his help!)