The Parameter Group Number (PGN) is the J1939 identifier that defines a specific message broadcast on the CAN bus. Each PGN groups one or more Suspect Parameter Numbers (SPNs) into a single periodic message transmitted by an Electronic Control Unit (ECU). Knowing the PGN allows technicians and engineers to locate the exact message in the CAN bus traffic, understand its transmission rate and priority, and identify all the parameters it carries.
Use the lookup tool below to search any PGN from the SAE J1939DA standard. Enter the PGN number to instantly view its name, description, transmission rate, default priority, data length, and the complete list of SPNs it contains.
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SPNs in this PGN
PGNs are organized in the SAE J1939 standard by function and system. Low PGN numbers (0–4096) are typically reserved for high-priority control messages such as TSC1 (Torque/Speed Control 1, PGN 0) and TC1 (Transmission Control 1, PGN 256), which are transmitted at rates as fast as 10 ms during active control. Mid-range PGNs (57344–65279) cover proprietary and manufacturer-specific messages. High-range PGNs (65280–65535) are used for broadcast parameter groups carrying sensor data, diagnostic information, and vehicle status — this is where most of the diagnostic-relevant SPNs are found, including engine temperatures (PGN 65262), fuel economy (PGN 65257), and aftertreatment status (PGN 64892).
The default priority field (1–7) determines message arbitration on the CAN bus. Priority 3 is the most common for engine data broadcasts. Priority 6 and 7 are reserved for low-urgency informational messages. When two nodes transmit simultaneously, the lower priority number wins arbitration — this is why control messages (priority 3) always take precedence over status broadcasts (priority 6–7).
The data length field indicates whether the PGN uses a fixed-length frame (typically 8 bytes) or a variable-length transport protocol (BAM or CMDT) for messages exceeding 8 bytes. PGNs marked as variable-length require the J1939 Transport Protocol to reassemble multi-packet messages before the individual SPNs can be extracted.
For detailed fault code information on any SPN listed in a PGN, use the SPN FMI Lookup tool or browse the complete fault code database by system category.