Service Programming System (SPS) Description: Notes

WARNING: This page is about a different car, the 2002 GMC C3500 HD and 2002 Chevrolet C3500 HD. However, it is still accessible from the selected car via links, so may be relevant.

The service programming system (SPS) allows a technician to program a control module through the data link connector (DLC). The information transfer circuit that is used at the DLC is the same serial data circuit used by the scan tool for retrieving diagnostic trouble codes (DTCs), displaying data, clearing DTCs, etc. This procedure offers the ability to install software/calibrations matched to a particular vehicle.

Most control modules have 2 types of memory. The software/calibrations reside in the flash memory. The two types of memory are listed below:

Electrically Erasable Programmable Read Only Memory (EEPROM)
This type of memory allows selected portions of memory to be programmed while other portions remain unchanged.

Certain learned values reside in the EEPROM, such as:
- The vehicle identification number (VIN)
- The crankshaft variation learned position
- The software/calibrations identification numbers
- The control module security information
Flash Read Only Memory - Flash Memory
Flash memory has increased memory storage capacity. During programming, all information within this type of memory is erased, and then replaced with entirely new information.