PID

📖 YOUCANIC Automotive Glossary

PIDs (Parameter Identification Data) are standardized data channels defined by OBD2 (SAE J1979) that allow scanners to request specific real-time parameters from vehicle control modules. Each PID has a hexadecimal code: PID $05 returns coolant temperature, PID $0C returns RPM, PID $0D returns vehicle speed, PIDs $06/$07 return fuel trim. Mode $01 PIDs provide live data while Mode $02 PIDs return parameters frozen at the moment a DTC triggered. The OBD2 standard defines mandatory PIDs all vehicles must support, plus manufacturers add proprietary enhanced PIDs.

The number of available PIDs depends on your scanner’s capability. Basic code readers display perhaps a dozen standard PIDs, while the YOUCANIC UCAN-II accesses hundreds of enhanced manufacturer-specific PIDs including transmission, ABS, body module, and proprietary sensor readings. Understanding key PIDs and their normal ranges is essential for effective diagnosis — fuel trim PIDs reveal lean or rich conditions, O2 PIDs show sensor switching, coolant PIDs verify thermostat operation, and MAF PIDs confirm airflow readings.