Today, virtually all PCMs have reprogramming capabilities as do many other onboard control modules (ABS, air bags, climate control, body controller, etc.). Ford and Chrysler were also doing the same thing as OBD II arrived on all cars and light trucks in model year 1996. By 1995, most GM models had the flash reprogrammable PCMs. It is all done digitally with the proper access codes and input data.įollowing the Geo Storm, GM began phasing in PCMs with flash reprogrammable chips in a variety of cars and trucks. PCMs built with EEPROM chips can be reprogrammed in a matter of minutes without having to remove the PCM or replace a single chip. The General Motors PROM Identification manual that OTC used to provide with their Monitor scan tool and Pathfinder software contained more than 362 pages of GM PROM numbers!Įnter the flash reprogrammable EEPROM (Electronically Erasable Program Read Only Memory) chip. We are talking thousands of different PROMS. Every field fix or recall for an emissions or driveability problem created more part numbers to keep track of. Performance enthusiasts also liked replaceable PROMs because the chip could be replaced with one that provided more spark advance, fuel enrichment, a higher rev limit, etc., to squeeze more power out of the engine.īut replaceable PROMS had a serious drawback: there were too many of them! Every model year and every running change meant another PROM had to be created. It also meant that if a bug was later discovered in the original factory programming, it could be corrected in the field by simply replacing the original PROM with an updated corrected PROM (a tactic GM has successfully used over the years to fix many factory flaws). A replaceable PROM chip also meant the PCM could be “retuned” if necessary to correct certain kinds of emissions or driveability problems.
GM pioneered the replaceable PROM chip as a way of programming PCMs to fit a wide range of GM makes and models. Previously, Program Read Only Memory (PROM) chips held all of the PCMs vital calibration information and operating instructions.
The first such application was the 1990 Geo Storm. How to: American vehicles (GM Ford Chrysler) PCM flash reprogramming tutorial in detail for newbies.įlash reprogrammable PCMs have been ussed in vehicles since the 1990s.
0 kommentar(er)
