As an automotive repair expert at obd-de.com, I’ve spent countless hours diving into the intricacies of vehicle diagnostics. Recently, my exploration led me deep into the world of OBD2 Parameter IDs (PIDs), and the wealth of data they unlock within modern vehicles. This journey, sparked by curiosity around CAN bus communication and inspired by explorations into automotive hacking, has highlighted the power of understanding Obd2 Pid Lists.
Initially, my investigation involved using tools like the OBDLink MX to interact with my vehicle’s CAN bus. While Bluetooth OBD2 adapters are convenient, I quickly encountered limitations due to bandwidth constraints, especially when trying to monitor continuous OBD2 traffic. Buffer overruns became a frequent issue, even after meticulous filtering. To overcome this, I opted for a wired USB OBD2 ELM327 module. This switch provided the robust and uninterrupted connection needed for in-depth data analysis, eliminating packet loss and ensuring comprehensive data capture.
One significant revelation during this process came from analyzing full PID scans performed with software like Torque. The responses revealed numerous “NULL PIDs,” indicated by a “7F” response code. This seemingly negative result was actually a breakthrough. It dawned on me that these skipped PIDs, the ones returning null values, were prime candidates for housing valuable data – potentially enhanced or manufacturer-specific PIDs not included in standard OBD2 protocols. By meticulously parsing the full PID scan data, and focusing on the ranges of PIDs that were not returning standard values (Hex 0-F), I began to identify a pool of potential enhanced PIDs ripe for further investigation.
This approach offers a strategic advantage. Instead of blindly searching through an overwhelming number of possible PIDs, we can narrow our focus to these “suspect” ranges. This targeted method allows us to efficiently pinpoint functional PIDs, cross-reference them with any known or documented PIDs, and ultimately, begin the crucial work of reverse engineering proprietary automotive data protocols.
My next step involves leveraging the wired USB ELM327 scanner to capture detailed communication on the CAN bus. A key objective is to determine if data points for Tire Pressure Monitoring System (TPMS) pressure and temperature are transmitted from the Body Control Module (BCM) to the Engine Control Module (ECM). Observing the data stream while switching the Driver Information Center (DIC) to the TPMS screen could potentially reveal these values within a single scan session.
This exploration into OBD2 PIDs also intersects with another fascinating area: automotive customization and control. My interest in an OBD2 window rollup/rolldown module led me to investigate the unlock/lock command sequences on the CAN bus. By understanding these communication patterns, I could decipher how the module successfully controls all four windows. To facilitate simultaneous analysis and module operation, I plan to use an OBD2 splitter cable. This will allow me to “sniff” the CAN bus traffic while the window module is actively communicating on the network. This setup promises to reveal the precise messages responsible for window control and potentially other vehicle functions. Interestingly, the window module also triggers the hazard lights upon door opening and closing – a subtle but potentially useful safety feature, particularly when parked in urban environments.
For those eager to delve deeper into vehicle bus hacking and OBD2 analysis, I highly recommend exploring these resources:
- A Complete Guide to Hacking Your Vehicle Bus on the Cheap & Easy – Part 1 (Hardware Interface)
- A Complete Guide to Hacking Your Vehicle Bus on the Cheap & Easy – Part 2 (Interpreting the Data)
- ELM327 Datasheet
- The Car Hacker’s Handbook
Beyond the technical aspects of OBD2 PIDs and data analysis, the practical application of this knowledge extends to enhancing the driving experience. Inspired by creative mounting solutions for tablets and phones seen within the automotive community, I’m considering a rearview mirror mount for my Android phone dedicated to displaying real-time gauges via OBD2 data. Additionally, a separate dash mount for my iPhone is planned. Integrating a V1 radar detector with a BlendMount is also on the horizon, strategically positioning the Android Torque display to the left of the rearview mirror for optimal visibility. This may necessitate a custom bracket solution using components from RAM Mounts to achieve the desired landscape orientation and placement.
This ongoing exploration into OBD2 PID lists and vehicle communication systems continues to yield exciting insights. I will be sharing further updates as progress is made in deciphering enhanced PIDs, analyzing CAN bus traffic, and unlocking the full potential of vehicle diagnostic data. Stay tuned for more discoveries in the fascinating world of automotive technology!
