SAE J1939 / CAN Bus Training
Learn CAN Bus and SAE J1939 communication from CAN_H / CAN_L wiring and 29-bit identifiers to PGNs, SPNs, source addresses, PDU formats, address claiming, transport protocol, DM1 / DM2 diagnostics, DTC interpretation and practical ECU network analysis.
Learn the Communication Language of Heavy-Duty Electronic Systems
SAE J1939 builds a standardized higher-level communication system on top of CAN and is widely associated with heavy-duty vehicles, engines, construction machinery, agricultural equipment, mobile equipment and off-highway electronic systems.
CAN Bus + SAE J1939 Engineering
The NCVT J1939 / CAN Bus program begins with CAN physical wiring, differential signalling, termination, arbitration, frames and extended identifiers.
Learners then progress into J1939 message architecture, PGNs, SPNs, source addresses, destination-specific and broadcast messages, address claiming, transport protocol and diagnostic communication.
From Raw CAN Frames to Vehicle Data
CAN transports the message. J1939 gives standardized meaning and structure to many messages so ECUs can exchange operating, status and diagnostic information.
CAN Bus and J1939 Are Not the Same Thing
CAN Bus
CAN provides reliable message transport between electronic controllers on a shared two-wire differential network.
- CAN_H and CAN_L
- Differential signalling
- Bus termination
- Message identifiers
- Arbitration
- CRC and acknowledgement
- Error handling
- Multi-master communication
- Standard and extended frames
SAE J1939
J1939 defines a higher-level communication model using extended CAN identifiers and standardized parameter concepts.
- 29-bit CAN identifiers
- Priority
- Source addresses
- Destination addressing
- PGNs
- SPNs
- Address claiming
- Transport protocol
- Diagnostic messages
Practical J1939 Network Training
What You Will Learn
CAN Bus Engineering
- CAN network architecture
- CAN_H and CAN_L wiring
- Differential signalling
- 120-ohm termination concepts
- CAN controllers and transceivers
- Standard and extended identifiers
- CAN frame structure
- Arbitration
- Bit timing fundamentals
- CRC and acknowledgement
- Error handling
- Bus diagnostics
SAE J1939 Engineering
- 29-bit J1939 identifier
- Priority field
- Source address
- PDU Format and PDU Specific
- PDU1 and PDU2 messages
- Parameter Group Number — PGN
- Suspect Parameter Number — SPN
- Scaling and offsets
- Address claiming
- Transport protocol
- Diagnostic messages
- CAN trace interpretation
J1939 Technologies Covered
Understand the J1939 29-Bit Identifier
The extended CAN identifier contains fields that communicate message priority, parameter-group information and the source of the transmission.
Learn How J1939 Organizes Vehicle Information
PGN
Parameter Group Numbers identify groups of related information transmitted within a J1939 network.
SPN
Suspect Parameter Numbers identify individual parameters or signals defined within J1939 data.
FMI
Failure Mode Identifier information describes the type of detected abnormal condition associated with a parameter.
Source Address
The source address identifies which network ECU transmitted the J1939 message.
Address Claim
J1939 devices use address-claim mechanisms to establish and manage source addresses on the network.
Transport Protocol
Transport Protocol mechanisms allow information larger than a normal classic-CAN data payload to be transferred.
DM1
DM1 is used for active diagnostic trouble-code information and associated diagnostic status.
DM2
DM2 is associated with previously active diagnostic trouble-code information.
SAE J1939 / CAN Bus Curriculum
Progress from CAN physical-layer fundamentals into extended identifiers, PGNs, SPNs, address claiming, transport protocol, diagnostics and complete ECU-network analysis.
Introduction to Vehicle Networks
ECUs, distributed control, embedded networks, automotive communication and off-highway network architecture.
CAN Bus Fundamentals
CAN controllers, transceivers, network nodes, multi-master communication and CAN operation.
CAN Physical Layer
CAN_H, CAN_L, differential signalling, wiring, termination, topology and practical bus layout.
CAN Frames & Arbitration
CAN identifiers, data frames, dominant and recessive states, message priority and arbitration.
CAN Errors & Diagnostics
CRC, acknowledgement, error frames, error counters, bus faults and communication troubleshooting.
Introduction to SAE J1939
J1939 architecture, application areas, ECU communication model and relationship with CAN.
29-Bit J1939 Identifier
Priority, data-page concepts, PDU Format, PDU Specific and source-address fields.
PDU1 & PDU2 Formats
Destination-specific messages, broadcast parameter groups, destination-address concepts and group-extension concepts.
Parameter Group Number — PGN
PGN structure, parameter groups, message identification and interpretation of J1939 traffic.
Suspect Parameter Number — SPN
Signal definitions, byte and bit positions, scaling, offsets, ranges and engineering values.
Source Addresses & ECU Communication
Source addressing, ECU identification, network participants and message-source analysis.
Address Claiming & NAME
Address-claim concepts, device identity, network address conflicts and dynamic address management.
Request & Response Communication
Requesting parameter groups, ECU responses, destination addressing and on-demand communication.
J1939 Transport Protocol
Multi-packet communication, connection-management concepts, BAM and RTS/CTS transfer mechanisms.
J1939 Diagnostics & DTCs
Diagnostic trouble codes, SPN, FMI, occurrence information, lamp concepts and diagnostic message interpretation.
DM1 & DM2 Diagnostic Messages
Active faults, previously active faults, diagnostic-message decoding and service-oriented analysis.
CAN Trace Analysis & Troubleshooting
Capture J1939 traffic, identify ECUs, decode PGNs, extract SPNs and investigate communication faults.
J1939 ECU Network Project
Analyze or build a practical multi-node J1939 network with messages, parameters, diagnostics and troubleshooting.
From CAN Wiring to Decoded J1939 Data
Learn a systematic engineering approach to analyzing and troubleshooting a vehicle or mobile-machine network.
Inspect
Check bus wiring and termination.
Connect
Connect a CAN diagnostic interface.
Capture
Record extended CAN frames.
Decode
Identify PGNs and SPNs.
Diagnose
Analyze faults and DTCs.
Validate
Confirm correct network operation.
SAE J1939 / CAN Bus Projects
CAN Physical Network
Build and test a CAN_H / CAN_L network with correct bus termination and node wiring.
29-Bit Identifier Analysis
Break down extended identifiers into priority, PF, PS and source-address information.
PGN / SPN Decoder
Identify parameter groups and decode individual signals from captured J1939 messages.
Address Claim Exercise
Study ECU source addressing, device identity and network address-claim behaviour.
DM1 Fault Analysis
Interpret active diagnostic information and understand SPN / FMI-based fault reporting.
Complete J1939 Network Analysis
Capture, decode and troubleshoot a multi-node CAN/J1939 communication system.
Where SAE J1939 Is Applied
Who Can Join?
- Embedded systems engineers
- Automotive engineers
- Electronics engineers
- Electrical engineers
- Mechatronics engineers
- Firmware developers
- Automation engineers
- Off-highway equipment engineers
- Service engineers
- Diagnostics engineers
- Engineering and diploma students
Career & Skill Direction
- J1939 Communication Engineer
- CAN Bus Engineer
- Automotive Embedded Engineer
- ECU Integration Engineer
- Vehicle Network Engineer
- Off-Highway Electronics Engineer
- ECU Diagnostics Engineer
- Telematics Engineer
- Embedded Systems Engineer
- Field Application Engineer
- Mobile Equipment Service Engineer
Progress from CAN Fundamentals to Vehicle Network Engineering
SAE J1939 / CAN Bus FAQs
What is SAE J1939?
SAE J1939 is a family of standards used for communication between electronic control units in many heavy-duty vehicle and mobile-equipment applications.
Does J1939 use CAN Bus?
Yes. J1939 uses CAN communication and commonly uses the extended 29-bit CAN identifier format.
What is a PGN?
PGN stands for Parameter Group Number. It identifies a defined group of related J1939 parameters or information.
What is an SPN?
SPN stands for Suspect Parameter Number. It identifies an individual parameter or signal used in J1939 data definitions.
What is the difference between PGN and SPN?
A PGN identifies a parameter group or message definition, while SPNs identify individual parameters contained within the defined J1939 information.
What are PDU1 and PDU2?
PDU1 is used for destination-specific J1939 communication, while PDU2 is associated with globally addressed parameter-group communication.
What is J1939 address claiming?
Address claiming is the mechanism used by J1939 nodes to establish and manage their source addresses on the network.
What is J1939 Transport Protocol?
Transport Protocol provides mechanisms for transferring information that is larger than a single classic CAN data payload.
What are DM1 and DM2?
DM1 is associated with active diagnostic trouble-code information. DM2 is associated with previously active diagnostic trouble codes.
Is J1939 the same as CANopen?
No. Both use CAN as an underlying network technology, but SAE J1939 and CANopen define different higher-level communication models and device concepts.
Is J1939 useful for off-highway equipment?
Yes. J1939 knowledge is relevant to many engine, transmission, vehicle, construction, agricultural, mining and mobile-machine electronic systems.
Start Your SAE J1939 / CAN Bus Training
Learn CAN wiring, 29-bit identifiers, PGNs, SPNs, PDU1/PDU2, source addresses, address claiming, transport protocol, DM1 / DM2 diagnostics, DTC interpretation and practical ECU network analysis.
Contact NCVT for J1939 Training →