Here's what's involved, and why it's typically done by professionals:
* No simple DIY method: There's no readily available software or consumer-grade hardware to reflash a 1998 Astro's PCM at home. OBD-II was around, but the protocols and PCM architecture were significantly different from modern systems.
* Professional reprogramming: To change the PCM's programming, you'd need to go to a shop specializing in automotive electronics or a dealership. They would likely:
* Remove the PCM: This involves locating it (usually under the hood or under the dash), disconnecting the electrical connectors, and removing it from its mounting.
* Send it to a specialist (or use in-house equipment): The PCM chip needs to be reprogrammed. This often involves sending the unit to a specialist who can either replace the PROM chip with a pre-programmed one or use a programmer to write directly to the chip. This isn't always possible depending on the chip type and availability of programming tools.
* Reinstall and calibrate: Once reprogrammed, the PCM is reinstalled, and potentially the system needs recalibration (this varies depending on what was changed).
* Why would you need to do this? The most common reason to consider this level of intervention would be:
* Severe internal PCM failure: Sometimes, the PCM's internal programming gets corrupted, requiring a replacement or reprogramming of the PROM chip.
* Very specific tuning needs: Extremely rare, and usually not practical for a 1998 vehicle due to the cost and effort involved. There are no widely available performance tuning options for this older system compared to modern vehicles.
In short: Unless you have advanced electronics skills, specialized equipment, and experience with these older GM systems, attempting to "reflash" the PCM yourself is not recommended. It's best to seek professional help from a reputable auto shop or GM dealership. A faulty PCM typically leads to a replacement rather than a reprogramming effort.
