The Engine Variable Geometry Turbocharger (VGT) Actuator Software Identification parameter, designated as Suspect Parameter Number (SPN) 6713, is a non-diagnostic, informational data point transmitted on the SAE J1939 Controller Area Network (CAN) bus. Unlike fault-driven SPNs that monitor circuit health or physical parameters, SPN 6713 serves a specific purpose in system identification and component validation. It reports the unique software version or part number currently programmed into the VGT actuator’s internal microcontroller. This parameter is critical for field service technicians and fleet managers because it allows the Engine Control Module (ECM) and diagnostic tools to verify that the actuator is running the correct calibration for the specific engine application. In real-world contexts, SPN 6713 is commonly encountered on modern heavy-duty diesel engines equipped with variable geometry turbochargers, such as the Cummins ISX15, Detroit Diesel DD15, PACCAR MX-13, Volvo D13, and Caterpillar C15 ACERT. When a VGT actuator is replaced, or its firmware is updated, the ECM reads SPN 6713 to confirm compatibility with the engine’s overall control strategy. Without this verification, mismatched software can lead to incorrect vane positioning, reduced boost pressure control, and potential engine derates.
Technical Overview
SPN 6713 is not a measured physical value like voltage or pressure; rather, it is a digital data string embedded in the actuator’s firmware. The VGT actuator is a mechatronic device that typically contains a brushless DC motor, a position feedback sensor (often a Hall-effect or resolver), and a dedicated microcontroller. This microcontroller runs proprietary software that governs actuator response curves, fault detection algorithms, and communication protocols. When the ECM requests the software identification, the actuator responds over the J1939 bus by transmitting a multi-byte message containing an ASCII or hexadecimal string representing the software part number or version. The normal operating range for this parameter is the set of all valid software identifiers that the OEM has released for that specific actuator hardware revision. For example, a Cummins VGT actuator might report “CMM_ISX15_VGT_Rev_3.2,” while a Detroit Diesel DD15 actuator might report “DDEC_VGT_2024_01.” The signal type is purely digital, transmitted as a CAN data frame. The ECM does not use SPN 6713 for real-time control; instead, it logs the value during key-on events or after actuator replacement. If the reported identifier does not match the expected value stored in the ECM’s configuration memory, the ECM may set a diagnostic trouble code (DTC) indicating a software mismatch, often accompanied by SPN 6713 as the identifier for the suspect parameter.
J1939 Network Behavior
On the J1939 CAN bus, SPN 6713 is transmitted as part of a Parameter Group (PGN) that is not publicly listed in the standard J1939-71 document—this is a proprietary PGN defined by the engine OEM. In practice, this PGN is often assigned to a Manufacturer Specific (MS) range, typically between 0xFF00 and 0xFFFF. The transmission rate for this parameter is event-driven: it is broadcast once upon power-up (key-on) or when a diagnostic tool explicitly requests it via a Request for Parameter Group (PGN 0x00EA00). The source address of the message is the VGT actuator itself, which has a dedicated source address (SA) assigned during network configuration, often in the range of 0x80 to 0xBF for intelligent actuators. Other ECUs on the network, such as the transmission controller or aftertreatment control module, do not directly use SPN 6713 for control functions. However, the ECM uses this data to validate that the actuator software is compatible with the engine calibration. Additionally, a J1939 diagnostic tool or OEM service software (e.g., Cummins INSITE, Detroit Diesel Diagnostic Link, or PACCAR PACCAR Solutions) can read SPN 6713 to identify the exact software version on the actuator without requiring physical access to the component. This is particularly useful when troubleshooting intermittent boost control issues where a mismatched actuator firmware is suspected.
Diagnostic Importance
Although SPN 6713 is not a fault code in itself, it is intrinsically linked to diagnostic importance because an unexpected value can trigger a DTC. When the ECM detects that the software identification reported by the VGT actuator does not match the expected identifier stored in its memory, it typically sets a DTC such as “VGT Actuator Software Mismatch” (often with an associated SPN 2791 or SPN 641). In response, the ECM may invoke an engine protection strategy that includes limiting maximum boost pressure, reducing engine power (derate), or even locking the actuator in a safe position to prevent overboost or underboost conditions. Ignoring a fault code related to SPN 6713 can have serious consequences: the engine may operate at reduced performance for extended periods, leading to increased fuel consumption, higher exhaust temperatures, and potential damage to the turbocharger or aftertreatment system. Furthermore, if a technician replaces a VGT actuator without verifying the software version, the engine may fail to meet emissions standards or enter a permanent derate until the correct calibration is flashed. For fleet operations, this can result in unexpected downtime and costly roadside repairs. Therefore, SPN 6713 is a critical piece of information during any VGT actuator replacement or firmware update procedure.
Common Failure Patterns
Real-world failure patterns involving SPN 6713 are rarely due to the parameter itself but rather to the underlying conditions that cause a mismatch. The most frequent scenario is a technician installing a replacement VGT actuator that has outdated or incorrect firmware. For example, a Cummins ISX15 engine requiring actuator software version “C-2024-01” might receive a rebuilt actuator still running “C-2022-01” from a different engine family. This mismatch triggers a DTC that references SPN 6713. Another common pattern is a failed firmware update during a field service campaign—if the flashing process is interrupted (e.g., battery disconnect or CAN bus failure), the actuator may report a corrupted or incomplete software identifier. Wiring issues are less common for SPN 6713 itself because the parameter is digital and transmitted over the CAN bus; however, a damaged CAN bus line (e.g., short to ground or open circuit) can prevent the ECM from receiving the actuator’s response, leading to a “No Communication” DTC that may be confused with a software mismatch. Contamination or calibration drift in the actuator’s position sensor does not directly affect SPN 6713, but if the actuator fails mechanically, the ECM may still read the correct software version while the vane control is erratic. In such cases, technicians must differentiate between a software mismatch (SPN 6713 related) and a mechanical failure (related to SPN 2791 or SPN 102).
Diagnostic Approach
When a diagnostic trouble code referencing SPN 6713 is encountered, the technician should follow a structured diagnostic approach. First, connect a J1939-compatible diagnostic tool (e.g., Noregon JPRO, Cummins INSITE, or Detroit Diesel Diagnostic Link) and read the active and inactive DTCs. Note the specific fault code associated with SPN 6713—often “Software Mismatch” or “Invalid Software ID.” Next, verify the software version currently reported by the VGT actuator. This is done by navigating to the actuator’s parameter list in the diagnostic tool and reading the value for SPN 6713. Compare this value to the expected software identifier for the specific engine model and calibration, which can be found in the OEM’s service documentation or technical bulletin. If a mismatch is confirmed, the corrective action is to flash the correct software into the actuator using the OEM’s proprietary programming tool. For example, with Cummins engines, this requires INSITE and a valid calibration file; for Detroit Diesel, it requires DDDL and the appropriate software package. Before flashing, perform a circuit check: verify that the CAN bus termination resistors are intact (120 ohms across CAN High and CAN Low at the actuator connector), check for 12V or 24V power and ground at the actuator, and inspect the connector pins for corrosion or bent terminals. If the software version matches but the DTC persists, suspect a CAN bus communication issue—measure resistance and voltage levels with a multimeter or oscilloscope. Finally, if all checks pass and the software is correct, escalate to the OEM’s technical support, as the actuator’s microcontroller may have an internal fault requiring replacement. Never attempt to bypass or clear the DTC without resolving the root cause, as the ECM will continue to enforce protection strategies.
Fault Codes for SPN 6713
FMI 0: Data valid but above normal operational range (most severe)
SPN 6713 FMI 0 indicates the VGT actuator’s software identification data exceeds normal operational parameters, typically signaling corrupted firmware or version incompatibility. This fault commonly appears after ECM reflashing procedures when technicians encounter turbocharger actuator software tha
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FMI 1: Data valid but below normal operational range (most severe)
This fault indicates the Engine Variable Geometry Turbocharger Actuator Software Identification signal is valid but below the normal operational range. The ECM detects the actuator’s software version or configuration data is too low, often occurring after an incomplete ECM reflash, actuator replacem
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FMI 2: Data erratic, intermittent or incorrect
SPN 6713 FMI 2 indicates erratic or incorrect data from the variable geometry turbocharger actuator software identification. This fault often arises after software updates or ECM replacements, causing inconsistent engine performance. Technicians frequently encounter this issue when dealing with inco
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FMI 3: Voltage above normal or shorted high
SPN 6713 FMI 3 indicates excessive voltage in the VGT actuator software identification circuit, typically exceeding 5.0V threshold. This fault commonly appears during cold weather startups when moisture infiltrates connector pins, or after ECM reflashing procedures when actuator initialization seque
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FMI 4: Voltage below normal or shorted low
SPN 6713 FMI 4 indicates the Engine Variable Geometry Turbocharger Actuator Software Identification circuit voltage is below normal or shorted low. This fault commonly appears after a forced DPF regeneration when excessive heat damages the actuator harness insulation, causing a short to ground. The
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FMI 5: Current below normal or open circuit
SPN 6713 FMI 5 occurs when the software identification of the variable geometry turbocharger actuator reports a current below normal or an open circuit. This fault is commonly encountered after a software update or if the actuator is replaced without proper calibration. Technicians often see this co
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FMI 6: Current above normal or grounded circuit
This fault indicates excessive current flow through the VGT actuator control circuit, typically occurring during forced regeneration cycles or after ECM software updates. The engine control module detects current levels exceeding normal operating parameters in the turbocharger actuator positioning s
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FMI 7: Mechanical system not responding properly
SPN 6713 FMI 7 indicates that the Engine Variable Geometry Turbocharger Actuator software has detected a mechanical system that is not responding properly. This fault commonly appears after a forced DPF regeneration when the actuator fails to return to its commanded vane position, often due to carbo
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FMI 9: Abnormal update rate
This fault indicates the engine ECM detects abnormal communication timing from the VGT actuator software identification system. The actuator’s embedded controller fails to transmit status updates within specified intervals, typically 50-100ms windows. Technicians commonly encounter this code after E
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FMI 11: Root cause not known
The SPN 6713 FMI 11 code is related to the software identification of the variable geometry turbocharger actuator. This fault often appears in practice when there is a software mismatch during ECM updates or replacements. Technicians frequently encounter this fault after replacing the ECM, especiall
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FMI 12: Bad intelligent device or component
SPN 6713 FMI 12 indicates a failed intelligent device within the variable geometry turbocharger actuator system, specifically relating to corrupted or invalid software identification. This fault commonly appears after ECM reflashing procedures when the VGT actuator’s internal microcontroller loses c
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FMI 13: Out of calibration
SPN 6713 FMI 13 indicates the engine variable geometry turbocharger actuator software identification is out of calibration. This fault commonly appears after replacing the turbocharger actuator or ECM without performing a required calibration procedure. In practice, technicians frequently encounter
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FMI 14: Special instructions
SPN 6713 FMI 14 indicates that the ECM has received a software identification mismatch or special instruction from the variable geometry turbocharger (VGT) actuator. This occurs when the actuator’s internal firmware does not match the expected calibration or when a forced update is required. Technic
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FMI 18: Data valid but below normal operating range (moderately severe)
SPN 6713 FMI 18 pertains to the software identification of the variable geometry turbocharger actuator, with data being valid but below the normal range. This fault often appears after an ECM update or replacement, where the actuator fails to properly synchronize with the updated software, leading t
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FMI 31: Condition exists
SPN 6713 FMI 31 indicates the ECM has detected a condition exists with the variable geometry turbocharger actuator software identification system. This fault commonly appears after ECM replacement or software updates when the turbocharger actuator’s embedded software version cannot be properly read