The question often arises in automotive tuning circles: Can Obdii Tunerpro be used for direct PCM (Powertrain Control Module) programming? While the idea of modifying BIN files and log data from an OBD2 vehicle using TunerPro is appealing, the reality of directly programming these changes into the PCM is more complex than many might initially think. Without a method to effectively rewrite the modified BIN back to the PCM, the tuning efforts can become largely unproductive.
The core challenge boils down to saving the new, modified BIN file to the Programmable Read-Only Memory (PROM) within the PCM. There are generally two potential pathways to achieve this, each presenting its own set of obstacles:
PROM Removal and External Programming
One approach involves physically removing the PROM chip from the PCM and utilizing an external EEPROM (Electrically Erasable Programmable Read-Only Memory) programmer to write the new BIN file. This method is conceptually similar to techniques employed with older GM OBD1 systems.
However, this approach introduces several practical difficulties:
- Soldering Complexity: Many modern PCMs utilize PLCC (Plastic Leaded Chip Carrier) type PROMs, which can be challenging to solder and desolder, especially for individuals without specialized electronics repair experience. Repeated removal and insertion for tuning iterations would ideally require a PLCC ZIF (Zero Insertion Force) socket to prevent damage to the chip and the PCM.
- PCM Accessibility: The physical location of the PCM within a vehicle can sometimes be quite inaccessible, making the process of removal and PROM access cumbersome and time-consuming.
Flash Programming via DLC (Diagnostic Link Connector)
The second potential method involves updating the PCM’s BIN file directly through the vehicle’s DLC, the standard OBD2 port. This would require a program capable of initiating a BIN update request to the PCM and then transmitting the new BIN data.
While seemingly straightforward in principle, this approach also faces significant hurdles:
- Software Development Requirement: Creating software capable of communicating with various PCM types to initiate and execute a flash programming sequence is a substantial undertaking. It would necessitate in-depth knowledge of PCM communication protocols, which vary significantly across different vehicle manufacturers and models. Developing such software, even for a limited range of vehicles, requires specialized programming skills and considerable time investment.
- Hardware Interface Limitations: A hardware interface is needed to translate USB or serial data from a computer into the communication format understood by the PCM. While devices like the ELM327 are popular for OBD2 diagnostics and data logging, they may lack the necessary capabilities for reliable PCM flashing. Specifically, limitations such as the absence of “block transfer” capability could lead to extremely slow and potentially unreliable flashing processes.
The Feasibility for TunerPro Development
Considering the complexities of both PROM removal/programming and DLC flashing across a vast range of vehicle applications compatible with TunerPro, implementing a universal or even widely applicable PCM programming feature presents a formidable challenge. Researching and implementing every possible programming approach for the diverse array of PCMs encountered in TunerPro’s user base would demand an immense investment of time and resources.
In conclusion, while TunerPro excels in BIN modification and data analysis, direct PCM programming via TunerPro for OBD2 vehicles is not a simple or readily achievable feature due to the inherent complexities and variations in automotive PCM technology and communication protocols.
