Live ECU data
OBD-II PID dictionary
Parameter IDs let a scanner read live engine data. Here are the common ones with their formulas and units.
| PID | Parameter | Formula | Unit | Range | What it tells you |
|---|---|---|---|---|---|
| 0100 | Supported PIDs 01-20 | bitmask | — | — – — | Bitmask of which PIDs the ECU supports in range 01–20. |
| 0102 | Freeze DTC | code | — | — – — | The stored DTC that triggered the freeze frame. |
| 0103 | Fuel system status | code | — | 0 – 2 | Closed/open loop fuel status. |
| 0104 | Calculated engine load | A × 100 / 255 | % | 0 – 100 | Engine load as a percentage of maximum torque. |
| 0105 | Engine coolant temperature | A − 40 | °C | -40 – 215 | Coolant temperature; ~90 °C is normal operating temperature. |
| 0106 | Short-term fuel trim | (A−128) × 100/128 | % | -100 – 99.2 | Short-term correction to the fuel mixture. |
| 0107 | Long-term fuel trim | (A−128) × 100/128 | % | -100 – 99.2 | Long-term fuel correction; high values indicate a leak or sensor issue. |
| 010A | Fuel pressure | 3 × A | kPa | 0 – 765 | Fuel rail pressure. |
| 010B | Intake manifold pressure | A | kPa | 0 – 255 | Manifold absolute pressure; around 100 kPa at WOT on NA engines. |
| 010C | Engine RPM | (A×256+B) / 4 | rpm | 0 – 16383 | Engine revolutions per minute. |
| 010D | Vehicle speed | A | km/h | 0 – 255 | Road speed from the OBD system. |
| 010E | Timing advance | (A/2) − 64 | °BTDC | -64 – 63.5 | Ignition timing advance before top dead centre. |
| 010F | Intake air temperature | A − 40 | °C | -40 – 215 | Temperature of the air entering the engine. |
| 0110 | Mass airflow rate | (A×256+B) / 100 | g/s | 0 – 655.35 | Air entering the engine per second. |
| 0111 | Throttle position | A × 100 / 255 | % | 0 – 100 | Accelerator / throttle opening percentage. |
| 0112 | Secondary air status | code | — | — – — | Secondary air injection system status. |
| 0114 | O2 sensor voltage (B1S1) | A / 200 | V | 0 – 1.27 | Upstream oxygen sensor voltage. |
| 011C | OBD standard | code → name | — | 0 – 255 | Which OBD standard the vehicle conforms to. |
| 011F | Run time since start | A×256+B | s | 0 – 65535 | Seconds since the engine was started. |
| 0121 | Distance with MIL on | A×256+B | km | 0 – 65535 | Distance driven with the malfunction light on. |
| 012C | Commanded EGR | A × 100/255 | % | 0 – 100 | Commanded EGR opening. |
| 012E | Commanded EVAP purge | A × 100/255 | % | 0 – 100 | Commanded evaporative purge valve opening. |
| 012F | Fuel tank level | A × 100 / 255 | % | 0 – 100 | Fuel level in the tank. |
| 0146 | Ambient air temperature | A − 40 | °C | -40 – 215 | Outside air temperature from the ambient sensor. |
| 0149 | Accelerator pedal position | A × 100/255 | % | 0 – 100 | Accelerator pedal position. |
| 014C | Commanded throttle actuator | A × 100/255 | % | 0 – 100 | Commanded electronic throttle position. |
| 0151 | Fuel type | code → name | — | 0 – 16 | Identifies the fuel type (petrol, diesel, gas, etc.). |
| 015A | Relative accelerator position | A × 100/255 | % | 0 – 100 | Relative accelerator pedal position. |
| 015C | Engine oil temperature | A − 40 | °C | -40 – 210 | Engine oil temperature where supported. |
| 0163 | Engine torque | (A−125) × 100/125 | % | -100 – 100 | Engine torque as a percentage of max. |
| 016B | Odometer (where supported) | A×256×256×256 + … | km | 0 – — | Cumulative distance recorded by the ECU. |
| 0184 | Fuel rail pressure (diesel) | (A×256+B) × 10 | kPa | 0 – 655350 | Diesel common-rail fuel pressure. |
| ATRV | Battery voltage (ELM) | raw | V | 0 – 16 | Supply voltage read directly by ELM-style adapters. |
Use these with the live OBD scanner or the
PID live-data tool to read your engine in real time.