OBD Utils

The aim of this library is to provide utility methods to make it easier to work with the OBD-II protocol. This library only provides the interface/helper functions to make it easier to work with the protocol, and does NOT provides any bindings/transport to communicate with the underlying hardware.

A large part of the implementation is borrowed from EricSmekens's node-bluetooth-obd project.

CLI Usage:

# e.g. parse an OBD response
$ npx obd-utils parse "41 05 3C"
{
    "mode": "41",
    "pid": "05",
    "name": "temp",
    "unit": "Celsius",
    "value": 20
}

# e.g. get info for PID "05", i.e. engine temperature sensor
$ npx obd-utils info 05
{
    "mode": "01",
    "pid": "05",
    "bytes": 1,
    "name": "temp",
    "description": "Engine Coolant Temperature",
    "min": -40,
    "max": 215,
    "unit": "Celsius"
}

Programmatic Usage:

import { parseOBDResponse, getPIDInfo, getAllPIDs } from "obd-utils";

// Parse an OBD response
const parsedCommand = parseOBDResponse("41 05 3C");
console.log(parsedCommand);
/**
 * The resulting output will resemble:
 * IParsedOBDResponse {
 *      mode: '41',
 *      pid: '05',
 *      name: 'temp',
 *      unit: 'Celsius',
 *      value: '60'
 * }
 */

// Get the info for a PID
const info = getPIDInfo("0C");
console.log(info);
/**
 * The resulting output will resemble:
 * IObdPIDDescriptor {
 *      mode: '01',
 *      pid: '0C',
 *      bytes: 2,
 *      name: 'rpm',
 *      description: 'Engine RPM',
 *      min: 0,
 *      max: 16383.75,
 *      unit: 'rev/min'
 * }
 */

// List all PID IDs
const allPids = getAllPIDs();
console.log(allPids);
/**
 * The resulting output will resemble:
 * Array<IObdPIDDescriptor> [
 *    ...,
 *    {
 *       mode: '01',
 *       pid: '0C',
 *       bytes: 2,
 *       name: 'rpm',
 *       description: 'Engine RPM',
 *       min: 0,
 *       max: 16383.75,
 *       unit: 'rev/min'
 *    }
 * ]
 */

OBD2 list of PIDs

Index | PID | Description | Units ------------ |------------ | -------------| -------------- 1 | 00 | PIDs supported 00-20 | Bit Encoded 2 | 01 | Monitor status since DTCs cleared | Bit Encoded 3 | 02 | DTC that caused required freeze frame data storage | Bit Encoded 4 | 03 | Fuel system 1 and 2 status | Bit Encoded 5 | 04 | Calculated LOAD Value | % 6 | 05 | Engine Coolant Temperature | Celsius 7 | 06 | Short Term Fuel Trim - Bank 1,3 | % 8 | 07 | Long Term Fuel Trim - Bank 1,3 | % 9 | 08 | Short Term Fuel Trim - Bank 2,4 | % 10 | 09 | Long Term Fuel Trim - Bank 2,4 | % 11 | 0A | Fuel Pressure | kPa 12 | 0B | Intake Manifold Absolute Pressure | kPa 13 | 0C | Engine RPM | rev/min 14 | 0D | Vehicle Speed Sensor | km/h 15 | 0E | Ignition Timing Advance for #1 Cylinder | degrees relative to #1 cylinder 16 | 0F | Intake Air Temperature | Celsius 17 | 10 | Air Flow Rate from Mass Air Flow Sensor | g/s 18 | 11 | Absolute Throttle Position | % 19 | 12 | Commanded Secondary Air Status | Bit Encoded 20 | 13 | Location of Oxygen Sensors | Bit Encoded 21 | 14 | Bank 1 - Sensor 1/Bank 1 - Sensor 1 Oxygen Sensor Output Voltage / Short Term Fuel Trim | V 22 | 15 | Bank 1 - Sensor 2/Bank 1 - Sensor 2 Oxygen Sensor Output Voltage / Short Term Fuel Trim | V 23 | 16 | Bank 1 - Sensor 3/Bank 2 - Sensor 1 Oxygen Sensor Output Voltage / Short Term Fuel Trim | V 24 | 17 | Bank 1 - Sensor 4/Bank 2 - Sensor 2 Oxygen Sensor Output Voltage / Short Term Fuel Trim | V 25 | 18 | Bank 2 - Sensor 1/Bank 3 - Sensor 1 Oxygen Sensor Output Voltage / Short Term Fuel Trim | V 26 | 19 | Bank 2 - Sensor 2/Bank 3 - Sensor 2 Oxygen Sensor Output Voltage / Short Term Fuel Trim | V 27 | 1A | Bank 2 - Sensor 3/Bank 4 - Sensor 1 Oxygen Sensor Output Voltage / Short Term Fuel Trim | V 28 | 1B | Bank 2 - Sensor 4/Bank 4 - Sensor 2 Oxygen Sensor Output Voltage / Short Term Fuel Trim | V 29 | 1C | OBD requirements to which vehicle is designed | Bit Encoded 30 | 1D | Location of oxygen sensors | Bit Encoded 31 | 1E | Auxiliary Input Status | Bit Encoded 32 | 1F | Time Since Engine Start | seconds 33 | 20 | PIDs supported 21-40 | Bit Encoded 34 | 21 | Distance Travelled While MIL is Activated | km 35 | 22 | Fuel Rail Pressure relative to manifold vacuum | kPa 36 | 23 | Fuel Rail Pressure (diesel) | kPa 37 | 24 | Bank 1 - Sensor 1/Bank 1 - Sensor 1 (wide range O2S) Oxygen Sensors Equivalence Ratio (lambda) / Voltage | (ratio) 38 | 25 | Bank 1 - Sensor 2/Bank 1 - Sensor 2 (wide range O2S) Oxygen Sensors Equivalence Ratio (lambda) / Voltage | (ratio) 39 | 26 | Bank 1 - Sensor 3 /Bank 2 - Sensor 1(wide range O2S) Oxygen Sensors Equivalence Ratio (lambda) / Voltage | (ratio) 40 | 27 | Bank 1 - Sensor 4 /Bank 2 - Sensor 2(wide range O2S) Oxygen Sensors Equivalence Ratio (lambda) / Voltage | (ratio) 41 | 28 | Bank 2 - Sensor 1 /Bank 3 - Sensor 1(wide range O2S) Oxygen Sensors Equivalence Ratio (lambda) / Voltage | (ratio) 42 | 29 | Bank 2 - Sensor 2 /Bank 3 - Sensor 2(wide range O2S) Oxygen Sensors Equivalence Ratio (lambda) / Voltage | (ratio) 43 | 2A | Bank 2 - Sensor 3 /Bank 4 - Sensor 1(wide range O2S) Oxygen Sensors Equivalence Ratio (lambda) / Voltage | (ratio) 44 | 2B | Bank 2 - Sensor 4 /Bank 4 - Sensor 2(wide range O2S) Oxygen Sensors Equivalence Ratio (lambda) / Voltage | (ratio) 45 | 2C | Commanded EGR | % 46 | 2D | EGR Error | % 47 | 2E | Commanded Evaporative Purge | % 48 | 2F | Fuel Level Input | % 49 | 30 | Number of warm-ups since diagnostic trouble codes cleared | 50 | 31 | Distance since diagnostic trouble codes cleared | km 51 | 32 | Evap System Vapour Pressure | Pa 52 | 33 | Barometric Pressure | kPa 53 | 34 | Bank 1 - Sensor 1/Bank 1 - Sensor 1 (wide range O2S) Oxygen Sensors Equivalence Ratio (lambda) / Current | (ratio) 54 | 35 | Bank 1 - Sensor 2/Bank 1 - Sensor 2 (wide range O2S) Oxygen Sensors Equivalence Ratio (lambda) / Current | (ratio) 55 | 36 | Bank 1 - Sensor 3/Bank 2 - Sensor 1 (wide range O2S) Oxygen Sensors Equivalence Ratio (lambda) / Current | (ratio) 56 | 37 | Bank 1 - Sensor 4/Bank 2 - Sensor 2 (wide range O2S) Oxygen Sensors Equivalence Ratio (lambda) / Current | (ratio) 57 | 38 | Bank 2 - Sensor 1/Bank 3 - Sensor 1 (wide range O2S) Oxygen Sensors Equivalence Ratio (lambda) / Current | (ratio) 58 | 39 | Bank 2 - Sensor 2/Bank 3 - Sensor 2 (wide range O2S) Oxygen Sensors Equivalence Ratio (lambda) / Current | (ratio) 59 | 3A | Bank 2 - Sensor 3/Bank 4 - Sensor 1 (wide range O2S) Oxygen Sensors Equivalence Ratio (lambda) / Current | (ratio) 60 | 3B | Bank 2 - Sensor 4/Bank 4 - Sensor 2 (wide range O2S) Oxygen Sensors Equivalence Ratio (lambda) / Current | (ratio) 61 | 3C | Catalyst Temperature Bank 1 / Sensor 1 | Celsius 62 | 3D | Catalyst Temperature Bank 2 / Sensor 1 | Celsius 63 | 3E | Catalyst Temperature Bank 1 / Sensor 2 | Celsius 64 | 3F | Catalyst Temperature Bank 2 / Sensor 2 | Celsius 65 | 40 | PIDs supported 41-60 | Bit Encoded 66 | 41 | Monitor status this driving cycle | Bit Encoded 67 | 42 | Control module voltage | V 68 | 43 | Absolute Load Value | % 69 | 44 | Fuel/air Commanded Equivalence Ratio | (ratio) 70 | 45 | Relative Throttle Position | % 71 | 46 | Ambient air temperature | Celsius 72 | 47 | Absolute Throttle Position B | % 73 | 48 | Absolute Throttle Position C | % 74 | 49 | Accelerator Pedal Position D | % 75 | 4A | Accelerator Pedal Position E | % 76 | 4B | Accelerator Pedal Position F | % 77 | 4C | Commanded Throttle Actuator Control | % 78 | 4D | Time run by the engine while MIL activated | minutes 79 | 4E | Time since diagnostic trouble codes cleared | minutes 80 | 4F | External Test Equipment Configuration #1 | Bit Encoded 81 | 50 | External Test Equipment Configuration #2 | Bit Encoded 82 | 51 | Fuel Type | Bit Encoded 83 | 52 | Ethanol fuel % | % 84 | 53 | Absolute Evap system Vapor Pressure | kPa 85 | 54 | Evap system vapor pressure | Pa 86 | 55 | Short term secondary oxygen sensor trim bank 1 and bank 3 | % 87 | 56 | Long term secondary oxygen sensor trim bank 1 and bank 3 | % 88 | 57 | Short term secondary oxygen sensor trim bank 2 and bank 4 | % 89 | 58 | Long term secondary oxygen sensor trim bank 2 and bank 4 | % 90 | 59 | Fuel rail pressure (absolute) | kPa 91 | 5A | Relative accelerator pedal position | % 92 | 5B | Hybrid battery pack remaining life | % 93 | 5C | Engine oil temperature | °C 94 | 5D | Fuel injection timing | ° 95 | 5E | Engine fuel rate | L/h 96 | 5F | Emission requirements to which vehicle is designed | Bit Encoded 97 | 62 | Actual engine - percent torque | % 98 | 67 | Engine coolant temperature | Celsius 99 | 6B | Exhaust gas recirculation temperature | Celsius 100 | 6D | Fuel pressure control system | Celsius 101 | 6E | Injection pressure control system | Celsius 102 | 73 | Exhaust pressure | Celsius 103 | 78 | Exhaust Gas temperature Bank 1 | Celsius

LICENSE

This module is available under a Apache 2.0 license, see also the LICENSE file for details.