OBDII Logger: Easily Record & Visualize Your Car Data

Looking to capture OBDII data from your vehicle?

This guide dives into the fundamentals of OBDII logging, highlighting the key benefits and practical applications. You can also access sample OBDII data from an Audi A4, including parameters like speed and RPM, to get started.

Unlike many OBDII dongles and scanners, the CANedge empowers you to log and analyze your car’s data your way, offering 100% free software and APIs, including browser-based dashboards:

OBD2 Telematics Dashboard Browser Free Open Source

Discover below why the CANedge stands out as the ideal solution for CAN and OBDII data logging and telematics applications.

Quick Tip: Watch our 4-minute introductory video above for a concise overview!

Understanding OBDII Data Logging

Let’s begin with a brief overview of OBDII basics.

OBDII provides a standardized set of parameters, known as OBDII PIDs, that can be recorded and easily interpreted across a wide range of vehicles.

Logging OBDII data involves a straightforward 3-step process:

Configure your Obdii Logger with a list of OBDII PIDs you wish to record.
Connect the logger to your car using an OBDII adapter to initiate data logging.
Extract the SD card from the logger and decode the recorded data using free software or APIs.

For more detailed instructions, refer to the FAQ section below or consult our comprehensive guides:

CLX000 OBDII Guide
CANedge OBDII Guide

Top 4 Advantages of OBDII Data Logging

OBDII logging offers the ability to collect data from virtually any modern vehicle. Here are four key benefits:

1. Driver, Vehicle, and Component Optimization

OBDII data empowers you to monitor and refine driving habits, optimize vehicle performance, and fine-tune your car. Original Equipment Manufacturers (OEMs) can leverage this data to assess the real-world performance of new prototype parts and equipment under diverse driving conditions. By logging parameters like engine load, RPM, speed, and throttle position, valuable insights can be gained for improving efficiency, performance, and durability.

2. Diagnosing Intermittent Issues

Some vehicle problems occur sporadically while driving but are absent during diagnostic checks in a repair shop. OBDII logging allows you to capture data precisely when these events occur. By analyzing the recorded data surrounding a specific incident, you can pinpoint the root cause of the problem, even if it’s infrequent or elusive. This capability is crucial for troubleshooting intermittent faults that traditional diagnostic methods may miss.

3. Enhancing Car Fleet Management

Implementing OBDII WiFi telematics across a vehicle fleet provides numerous advantages, including:

Driver Behavior Analysis: Monitor driving patterns to identify areas for improvement and promote safer driving habits.
Fuel Cost Reduction: Optimize routes and driving styles to minimize fuel consumption.
Reduced Breakdowns: Proactive monitoring and maintenance can help prevent costly breakdowns and downtime.
Compliance and Reporting: Track vehicle usage and performance for regulatory compliance and reporting purposes.
Dispute Resolution: Data-driven insights can aid in resolving disputes related to vehicle operation or incidents.
Predictive Maintenance: Utilize data trends to anticipate maintenance needs and schedule servicing proactively, minimizing downtime and extending vehicle lifespan. Learn more about predictive maintenance with CAN bus IoT.

4. Data Control and Custom Integration

An OBDII WiFi logger grants you complete control over your vehicle data. You record raw time-series data that can be extracted via an SD card or wirelessly uploaded to your own server. This open approach facilitates seamless custom integration with your existing systems through open APIs. You retain ownership and control of your data, enabling tailored analysis and application development.

Considering these benefits, which are most relevant to your OBDII logging needs? Feel free to contact us for a free consultation!

Introducing the CANedge OBDII Data Logger

The CANedge CAN bus data logger offers optional GPS/IMU, WiFi, and 3G/4G connectivity, making it an ideal solution for OBDII fleet telematics and advanced data logging applications:

PLUG & PLAY: Ready to log data right out of the box. Operates standalone. Connect your vehicles to your server effortlessly.

PRO SPECS: Features extractable 8-32 GB SD card, dual CAN/LIN channels, CAN FD support, zero data loss, 50 µs RTC timestamping, error frame detection, and MF4 logging format.

COMPACT: Small form factor at only 8 x 5 x 2 cm. Rugged design tested to 100G shock. Robust aluminum enclosure. Includes 5+ LEDs and configurable 5V power output (CH2).

WIFI/LTE: Push data wirelessly via WiFi or 3G/4G to your server. Enhanced end-to-end security. Supports Over-The-Air (OTA) updates for remote management.

GNSS + 3D IMU: Integrated GPS/IMU. Enhanced 3x accuracy through sensor fusion. Captures position, speed, distance, acceleration, and more.

INTEROPERABLE: Free open-source software and APIs. MF4 to ASC/CSV conversion. DBC support for decoding. Python API. Ready-to-use dashboards.

Learn more about CANedge

Software Example: Custom OBDII Dashboards

With the CANedge, you can effortlessly create free, personalized browser dashboards to visualize your OBDII data and set up custom alerts.

Combine your OBDII data with GPS/IMU data by using a CANedge with GNSS/IMU for enriched insights.

Explore our online playground or delve deeper into our dashboard introduction:

Online Playground
Dashboards Introduction

Get the ‘OBDII Data Pack’

Want hands-on experience with real OBDII data?

Download our ‘data pack,’ which includes:

Our OBDII DBC file
25+ car DBC files (reverse-engineered)
100+ MB of data from 10+ vehicles

Download Now

OBD2 data pack

OBDII Logger Use Case Examples

Below are practical examples illustrating how the CANedge can be effectively used for OBDII data logging in various scenarios.

OEM Field Testing of Vehicle Components

Need to log CAN/OBDII field data from vehicles in real-world conditions?

As an OEM, late-stage field testing of prototype equipment is crucial. This often necessitates collecting OBDII and CAN data from multiple vehicles over extended periods, such as months. The CANedge1 is ideally suited for this purpose due to its compact size, plug-and-play simplicity, and easy pre-configuration. Data can be collected periodically and analyzed using your preferred CAN tools or the free asammdf GUI/API.

CANedge1

Vehicle Telematics (OBDII + GNSS/IMU + 3G/4G)

Looking to establish OBDII telematics for on-road vehicle fleets?

The CANedge3 can wirelessly transmit recorded OBDII data via 3G/4G using your own SIM card. This enables near real-time wireless OBDII data transfer from vehicles to your private cloud server. The OBDII data can be automatically processed using open APIs, including OBDII DBC decoding support. CANedge3 devices support over-the-air updates for remote management. Moreover, the integrated GPS/IMU in the CANedge3 adds valuable data such as position, speed, trip distance, acceleration, and orientation to your data stream.

CANedge3

Case Study: OBDII/CAN Telematics

Volkswagen logo case study

Discover how Volkswagen utilizes the CANedge2 to log both OBDII and raw CAN data to an SD card and automatically push the data to their self-hosted server for in-depth analysis.

“The CANedge2 enabled us to get up and running quickly with robust configuration options, and the support was exceptional!”

Learn More
100+ Case Studies

OBD2 MDF4 Data Logger Pro

OBDII Data Sample from an Audi A4

You can download OBDII data samples recorded with the CANedge below.

We also provide free, open-source OBDII software, allowing you to experience the process of decoding raw OBDII data firsthand.

Raw OBDII Data
Decoded OBDII Data
Software

Frequently Asked Questions (FAQ) About OBDII Loggers

The OBDII protocol (SAE J1979) defines a standardized set of vehicle parameters that you can log from your car. However, the specific OBDII data supported can vary between car makes and models, with older vehicles often supporting fewer parameters.

Here are some common standardized OBDII parameters that are frequently accessible:

Fuel system status
Engine load
Coolant temperature
Fuel trim
Fuel pressure
Intake manifold pressure
Engine RPM
Vehicle speed
Intake air temperature
MAF air flow rate
Throttle position
Air status
Oxygen sensor status
Runtime since engine start
Distance with MIL on
Fuel tank level input
System vapor pressure
Absolute load value
Hybrid battery pack life
Engine oil temperature
Engine fuel rate
Torque
VIN
Various DTCs

For further details, consult the OBDII PID Wiki page or the SAE J1979 standard.

To convert raw OBDII data from a CANedge OBDII logger into meaningful physical values (e.g., km/h, RPM), you need a database of decoding rules and compatible OBDII software.

We offer a 100% free OBDII DBC file containing the majority of standardized Mode 01 (Service 01) OBDII PID decoding rules, as found on resources like the OBDII PID Wiki page.

The OBDII DBC file utilizes extended multiplexing to facilitate OBDII decoding. For more information, refer to our DBC introduction and our OBDII introduction, where we explain how to interpret raw CAN frames containing OBDII responses.

You can load your raw OBDII data and the OBDII DBC file into our free software tools, such as asammdf or our OBDII dashboard integrations. This enables you to visualize decoded OBDII data like speed, engine speed, MAF, and fuel level.

A key advantage of this approach is the ability to easily modify the OBDII DBC to incorporate additional proprietary OBDII PIDs. You can also combine the OBDII DBC with proprietary CAN DBC files to enable comprehensive CAN and OBDII car data logging.

What is UDS?

The Unified Diagnostic Services protocol (UDS, ISO 14229-1) is a communication protocol used within automotive ECU communication. A UDS diagnostic tool can send request messages on the CAN bus to retrieve information from specific ECUs. While OBDII is designed for on-board diagnostics during vehicle operation, UDS is primarily intended for off-board diagnostics when the vehicle is stationary.

How to Make UDS Requests over ISO-TP (ISO 15765-2)

Requesting OBDII PIDs is relatively simple: an OBDII scan tool or OBDII data logger sends a specific CAN frame (the OBDII request), and if the car supports the PID, it responds with a single CAN frame. In contrast, UDS requests may involve transport protocol requests. For example, using UDS service 0x22 to request data by identifier involves a more complex communication sequence:

A ‘UDS data logger’ sends a request frame specifying the service ID (SID) and data identifier (DID) of interest.
The car responds with a first frame containing the SID, DID, total message length, and initial payload bytes.
Shortly after, the UDS logger acknowledges with a flow control frame.
The ECU then sends consecutive frames with the remaining payload.

Therefore, logging UDS data requires a UDS tool capable of sending custom CAN frames and flow control frames. Software tools must also be able to reconstruct multi-frame UDS responses to extract and decode the payload.

UDS and OBDII Extended PIDs for Car Data Logging

The UDS service ID (SID) and data identifiers (DID) are sometimes combined into an ‘extended OBDII PID,’ such as 0x220101. Requesting UDS data via service 0x22 is used to access car data beyond standard OBDII PIDs. For example, some electric vehicles provide State of Charge (SoC%) information via UDS requests under service 0x22.

Using the CANedge as a UDS Data Logger

The CANedge can be configured to send UDS requests. This involves sending a request frame and a flow control frame within a specified timeframe after the request. This triggers the full sequence of UDS responses. The resulting log files with UDS responses can be analyzed in tools like CANalyzer (by converting MF4 data to Vector ASC) for decoding. Alternatively, the multi-frame UDS response data can be processed using our free Python CAN bus API to push parameters to a Grafana UDS dashboard. Our GitHub API examples library includes UDS response data and a UDS DBC file for decoding State of Charge (SoC%) from a Hyundai Kona EV. For more details, see our EV data logger article or contact us.

Is My Car OBDII Compatible?

Most likely, yes. OBDII is the standard for on-board diagnostics in cars and light trucks. It has been mandatory in the USA since 1996 and in the EU since 2003 (where it’s known as EOBD, essentially the same).

However, even with OBDII support, logging desired data isn’t guaranteed. Vehicle models vary in supported OBDII parameters, with older cars often having limited support for real-time parameters like speed and RPM. Some manufacturers are restricting OBDII data access for greater vehicle data control. While CAN bus is dominant for OBDII communication, older US cars (pre-2008) and some EU brands may use different protocols.

Important: Check your car’s OBDII connector for “metal pins” in CAN High (pin 6) and CAN Low (pin 14) – see our OBDII connector illustration (red pins). If unsure, send us a picture for verification.

There are 5 OBDII signal protocols:

ISO 15765 (CAN): Dominant, required in US vehicles since 2008.
SAE J1850 (PWM): Ford Motor Company standard.
SAE J1850 (VPW): General Motors standard.
ISO 9141-2: Used by Chrysler and some EU/Asian vehicles.
ISO 14230 (KWP2000): Primarily used by EU manufacturers.

The CANedge/CLX000 supports CAN-based OBDII. Contact us if you are unsure about your car’s compatibility.

For a rough protocol check, consult this resource: OBDII compatibility (cars). For OBDII basics, see our simple OBDII intro.

With an OBDII logger, you can verify supported Mode 01 OBDII parameter IDs by requesting ‘Supported PIDs’ parameters (IDs 00, 20, 40, 60, 80, A0, C0). Analyze the response data bytes bit-by-bit to determine PID support (see the Wikipedia OBDII PID article for details).

OBDII Logger vs. J1939 Logger

OBDII logging is generally for cars and light trucks. For heavy-duty vehicles (trucks, tractors, excavators), J1939 data logging is typically needed. J1939 is a standardized protocol in most heavy-duty vehicles, enabling cross-brand data decoding, similar to OBDII. A J1939 DBC file is required for decoding J1939 data. The CANedge/CLX000 can also function as a J1939 data logger.

Which OBDII Logger is Right for Me?

Both CANedge and CLX000 data logger series can be used as OBDII data loggers.

For SD card logging, the CANedge series is recommended – it’s the 2nd generation of CLX000, optimized for logging. For auto-uploading log files to your server, the CANedge2 is ideal, especially for OBDII telematics and OBDII dashboards.

For real-time OBDII data streaming via USB to your PC, the CLX000 series, like the CL2000, is recommended.

Can I Stream OBDII Data in Real-Time?

Yes, the CLX000 series supports real-time streaming of raw CAN and OBDII data via USB – see our OBDII streaming intro.

Raw CAN Data vs. OBDII Data Logging

Connecting a CAN logger like CANedge or CLX000 to your car’s OBDII port will by default start recording raw CAN bus data in most vehicles. This raw CAN data is broadcasted by vehicle sensors for internal communication.

OEMs may want to log raw CAN data as they possess the CAN database (DBC file) to decode it. For non-OEMs, decoding raw CAN data typically requires car hacking and reverse engineering. Partial databases for specific car models might be found online from projects like opendbc.

For most users outside of OEMs, OBDII protocol is the primary method for data collection. Most modern cars use CAN bus for OBDII communication. OBDII data is request-based, unlike raw CAN data. To log OBDII data, you send specific CAN frames into the vehicle CAN bus, essentially requesting data. The vehicle responds if the requested OBDII PID is supported.

Types of OBDII Devices

The market offers various OBDII device types:

OBDII Scanners: Used by mechanics for diagnostics, identifying trouble codes (DTCs), and clearing them. OBDII Bluetooth and WiFi scanners offer convenient smartphone access to diagnostic codes.

OBDII Dongles: Small, low-cost, user-friendly Bluetooth OBDII readers, often consumer-oriented. They provide real-time vehicle performance data via smartphone apps. They are plug-and-play but offer limited flexibility, often using an ELM327 microcontroller.

OBDII Data Loggers: Record OBDII time-series data to an SD card in standalone mode (no PC/app needed). Data is extracted via USB or SD card for later analysis. The CANedge1 is an example of a CAN bus data logger that can function as an OBDII data logger.

OBDII WiFi/LTE Loggers: Support WiFi or 3G/4G data transfer. The CANedge2/CANedge3 log OBDII data to SD cards and auto-transfer data to servers via WiFi/LTE, ideal for OBDII telematics and OBDII dashboards for fleet data visualization.

OBDII Interfaces: CAN interfaces that also stream OBDII data to a PC via USB. The CLX000 enables USB streaming of OBDII data to a PC using SavvyCAN.

Will the OBDII Logger Drain My Car Battery?

In most cases, no.

Typically, CANedge and similar loggers connected via the OBDII port power on/off with the ignition, as the OBDII connector usually uses the IGN power supply. This prevents battery drain when the car is off.

However, in some vehicles, the OBDII connector’s power supply is directly battery-connected, meaning the CANedge might remain powered even when the car is off. The logger’s power drain is minimal (<2W), so this is usually not an issue for short durations.

To verify, check the logger’s LEDs 15-20 minutes after turning off the car. If LEDs are off, the CANedge is off.

If the CANedge/CLX000 doesn’t turn off and the vehicle will be off for extended periods, disconnect the device. Alternatively, configure the CANedge to start/stop transmitting based on CAN data patterns related to ignition status. Another option is to use a DB9-DC splitter cable and a DC-cigarette receptacle adapter to power the logger via the cigarette lighter, which is typically ignition-linked. See the CANedge Docs for details.

Can I Log GPS Data with an OBDII Logger?

While your car may have built-in GPS, accessing this data via OBDII or proprietary CAN data is often not possible. We recommend using a CANedge with GNSS/IMU to record GNSS/IMU data synchronized with CAN/OBDII data from your car via Channel 1.

Ready to start OBDII data logging?

Get your CANedge OBDII Logger today!

Buy Now
Contact Us

Recommended for You

CANedge1 – Dual CAN Bus Data Logger
CANEDGE1 – PRO BLACK BOX LOGGER

CANedge2 – Dual CAN Bus Telematics Dongle
CANEDGE2 – PRO CAN IoT LOGGER

CAN BUS INTERFACE: STREAMING OBD2 DATA WITH SAVVYCAN