The memory and calibration unit is a removable part of the ECM. MEMCAL is GM-talk for PROM and it contains a 27C256 ROM, PROM, or EPROM. It also houses back-up fuel control system which consists of an IC and some analog circuitry.Can anyone explain what the MEMCAL and CALPAK do?
Calpak is the base "limp mode" calibration chip. In the GN's, it's the smaller chip under the ECM cover, as opposed to the PROM "Chip". It's basically a series of precision resistors in a matrix, which bypass and "hardwire" the engine's sensors and base functions.