OBD2 vs. CAN Bus Systems: Explained Protocols in Details

What is the OBD2 System?

The OBD2 system is something like a magical extension for measuring a car’s internal systems. The system could disseminate the internal objectives and the incumbent prospects of the indigenous malfunctions that occurred in the car’s system. Professional mechanics use an OBD2 scanner to diagnose the problem in the vehicle. It is the very initial process of diagnosis of the vehicle. The malfunction indicator light might be blinking on the dashboard if you see something unusual in the car’s system. That is your vehicle’s way of signaling a misinformation value sign of a problematic profound in. If you take your car to a mechanic, he might always start with an OBD2 system for checking the car.

Short overview: What is the CAN Bus?

The CAN Bus is a system that is composed of five different types of Controller area networks that are denoted as the CAN bus output signal, CAN data transfer algorithm, CAN bus message data structure, CAN bus output signal, and so on. Combinedly these modules are really helpful in interrogating the data transmission system of a vehicle. 

A CAN bus is mainly driven by connecting the most suitable devices for building up a data frame. The most intellectual standard message format. The transmission of the cohabitation workforce by the intensified wirings could be made an indigenous collaboration between the monologues. If The corresponding devices do not recognize the transmission, then wait for the largest emission. All the frame symposiums are linked to the ECU nodes in the network. An Identification number, a message, and other error correction bits combinedly demodulate the signals. Thus the CAN bus system can initiate the most crucial diagnosis for the transmission module.

Different types of CAN Bus:

CAN has an intensified module of frame types, and those systems are described as well-cooperated, 

  • Data Frame consists of fields that provide additional data related to the message. The main difference between these two formats is that the standard frame initiates an 11-bit identifier, and the extended demodulation frame identifies and signalizes the 29-bit identifier, which has got an extended 18-bit identifier. 
  • The receiver sends a remote Frame to request data from the transmitter. The differences between the remote frame and the data frame are that it does not contain any data field since it is not used for data transfer. 
  • There are many categories of error frame data. An active Error frame is transmitted by the node when an error is detected on a CAN network. A passive error flag is Transmitted by the node when a dynamic error is detected on a CAN network. Error Counters is an error is detected on a bus, then TEC or REC count increases.
  • The overload frame has a dimension of six dominant bits, while the overload flags are linked with other nodes. The overload congestion force consists of more or less eight recessive bits. 

What are the advantages of CAN Bus protocols?

CAN bus standard is an ideal system of protocols for safety applications. The durability and reliability of the vehicle are more or less incumbent on its robustness. You may have found several mechanisms to determine errors in the CAN protocol. Those mechanisms are called the cyclic redundancy check, bit stuffing, acknowledgment check, and bit monitoring, frame check. The CAN bus is a low-cost system and is very convenient to use. 

It is a message-based protocol, meaning nodes can easily be added or removed without performing any updates on the system. The data transmission speed of CAN is praise-worthy. The data transmit on two different occasions, the High-Speed CAN and Low-Speed CAN. It is much simple for nodes to communicate and navigate in this system. We can conclude that CAN is a much more convenient data transmission system than the OBD2. 

OBD2 vs. CAN Bus: All the core differences

Many of us miscalculate the dimension of the OBD2 and CAN Bus as the same exclamations, but it must be kept in mind that some intensified points make the thing two different outcomes. Here we will see the core differences between these two, 

Point of Conflict OBD2 CAN Bus
Definition Vehicle’s built-in self-diagnostic system monitors and receives information from the ECU and PCM. It is a higher layer of protocol, mainly a language used for diagnostic functions.  It is a network of independent controllers communicating securely. The communication system is made for vehicle intercommunication. This bus allows many microcontrollers and different types of devices to communicate with each other in real time.
Application Purpose  It is used for vehicle self-diagnosis. OBD2 can perform emissions, Transmission systems, Engine misfirings, TPMS, OCV checkings, mileage, speed, exhaust system, and so on. It mainly increases the data communications between the electrical control units. CAN protocol is used in household appliances and heavy-duty vehicles. 
Data communication speed  Sluggish process of diagnosing all the information related to the onboard diagnosis maneuver.  CAN bus is a high-speed communications protocol system
Type of data transmission  The limited opportunity of sending and receiving data as the process is a slow one. It can contain several data source values in only one message. So it is faster than OBD2.

Similarities: Both the CAN and OBD2 are used for the core data communication protocols. Whatever their differences are, they are used for authentic data management and transfer systems. However, CAN is much faster than OBD2 in terms of moving information.

Is OBD contradictory to the CAN system?   

In theory, the vehicle only needs a CAN to be in a precise position in the observatories. The ECU in the car plays a significant role in playing the outcomes and observatories in the manually understandable system. All other ECU is capable of governing the braking system, ABS system, OCV controlling system, and initially backdropped periodicals. If you try to switch on the reverse gear, it will likely be in a settled position. And this monitoring is done by the CAN system. It mainly has two electrical wires called “CAN Low and CAN High.” Is OBD contradictory to the CAN system

OBD2 is never opposed to the CAN bus system. Moreover, they are perfectly harmonious with each other. The SPN data allows the real users to keep bending on, maximizing vehicle performance. They can perform minor adjustments. All the ECUs units are connected to the CAN system. The external hardware process through the symbiotic revolutions in the vehicle’s adjustments. The necessary information gathered by the CAN bus sends a rigorous signal to users, leading to expensive damages and irreparable harm. The CAN system consists of Real-time data logging, whether the engine is on or deactivated.

It has the ability to view data immediately and with a lightning-fast symposium. The threshold alerts are very much effective in nullifying the errors. Irregular driving patterns can be very atrocious, and the austerity must bring on the engine. These protocols might have a hefty effect on the offloaded and exported information. Detailed analysis and recordkeeping are also common for the CAN profoundings. There are tons of advantages to logging in a CAN Bus communications. Harmonious, the OBD2 and CAN are the best duo in the vehicle’s fragmentation system.