SCAG STC48V-22FS Service Manual

Overview and safety considerations

General information and overview: The SCAG STC48V-22FS is a commercial-grade lawn care machine designed to deliver reliable cutting performance in demanding environments. Its compact frame and versatile 48V electric drive system enable efficient operation while minimizing emissions and fuel consumption. This section provides foundational knowledge about the machine's purpose, typical applications, and key subsystems, including the drive, cutting deck, electrical controls, and safety interlocks. Understanding these components helps technicians diagnose issues more accurately and perform routine maintenance with confidence. Operators should familiarize themselves with the machine’s intended use, operating envelope, and environmental considerations to ensure longevity and consistent performance across job sites. Regular inspection of components for wear, corrosion, or deformation is essential to maintain optimal function and reduce the risk of unexpected downtime.

Safety precautions and proper use: Before any service or operation, confirm that the battery pack is properly connected, secured, and displaying the correct voltage according to the manufacturer’s specifications. Always wear protective gear, including cut-resistant gloves and eye protection, when handling blades, pulleys, or electrical connections. Keep bystanders away from the work area and ensure the machine is on stable, level ground before starting. The control panel and safety interlocks must be tested to verify that the blade engagement, parking brake, and throttle functions respond correctly. Never operate the equipment in wet conditions or on uneven terrain that could compromise traction or blade control. Additionally, inspect the area for loose objects that could become projectiles during operation and remove them before beginning work.

General information and overview: The STC48V-22FS employs a modular design to facilitate field service and component replacement. Key access points are located for easy removal of the cutting deck, battery pack, and electrical harnesses without requiring specialized tools. When performing maintenance, disconnect the battery and use lockout/tagout procedures to prevent accidental re-energization. The charging system and battery management unit should be checked for proper voltage, state of charge, and thermal conditions during routine service intervals. Documentation, including part numbers and service dates, should accompany the unit to support traceability and warranty compliance. Proper torque values for fasteners are critical to avoid over-tightening or loosening under vibration.

Safety precautions and proper use: Follow all label instructions on components such as blade guards, shield assemblies, and discharge chutes, ensuring they are intact and correctly positioned before operation. Use manufacturer-approved replacement parts to preserve protective features and electrical insulation integrity. If any abnormal noises, vibrations, smoke, or unusual smells are detected during operation, stop immediately and perform a comprehensive fault diagnosis. Do not bypass safety interlocks or modify control circuits, as doing so can compromise operator protection and void warranties. Training for operators should cover start-up procedures, shutdown procedures, safe blade stopping, and emergency stop usage to minimize the risk of injury.

General information and overview: Routine checks should include the battery voltage, motor temperatures, belt wear, and deck alignment. Documented service intervals help ensure components like the drive motor, gear train, and bearings receive timely lubrication or replacement as needed. Calibration of sensors and actuators is necessary after any major service or if performance anomalies are observed. Environmental considerations, such as operating the machine within recommended temperature ranges and avoiding exposure to corrosive chemicals, enhance duty cycles and extend life. Proper storage practices, including battery isolation and protection from freezing or overheating, support long-term reliability.

Safety precautions and proper use: Always disengage the cutting blades and engage the parking brake before performing maintenance tasks with the deck elevated. Use a rated stand or lift to support the mower when access beneath the deck is required. Ensure electrical connectors are dry and free from contaminants before handling to prevent shorts or arcing. Keep hands and clothing away from moving parts, including belt drives and pulleys, during start-up tests or functional checks. Finally, maintain a clean and organized workspace to reduce trip hazards and ensure quick, safe access to emergency shutoffs if necessary.

SCAG STC48V-22FS is designed to deliver reliable performance in demanding outdoor environments while maintaining user-friendly serviceability. The machine operates with a 48-volt electric powertrain and a 22 horsepower class output, delivering steady torque for mid to heavy cutting tasks. Key specifications include a robust folding operator platform, reinforced chassis, and corrosion-resistant components intended for extended field use. The balance between power and efficiency is achieved through careful motor control and battery management, ensuring consistent cutting performance across a range of terrain. Regular checks of electrical connections, charging system status, and cooling pathways are essential to preserve peak operation and prolong service life.

In terms of capacity, the SCAG STC48V-22FS is equipped to handle standard residential and commercial mowing workloads with a dependable run-time profile supported by its high-cycle battery system. Battery capacity and discharge rates are matched to the motor controller to prevent thermal excursions during extended mowing sessions. The cutting deck is designed for uniform blade engagement and adjustable cutting heights, providing flexibility for varying grass conditions while maintaining uniform mulch and discharge performance. Service intervals emphasize inspection of drive belts, pulleys, and spindle assemblies to reduce downtime and ensure accurate deck alignment. Proper lubrication of moving parts and periodic blade sharpening are essential to maintain cutting efficiency and extend blade life.

Component identification and terminology covers critical assemblies including the drive system, battery pack, motor controller, and safety interlocks. The drive system comprises the axle housing, electric motors, differential or direct drive elements, and wheel assemblies, all of which require periodic inspection for wear and alignment. The battery system includes a modular pack configuration, cooling ducts, and charging connectors; understanding the color-coded cables and quick-release connectors helps technicians diagnose fault conditions quickly. The motor controller coordinates voltage and current delivery to the propulsion and cutting motors, with diagnostic ports and fault codes that guide maintenance steps. Safety devices such as the seat switch, dead-man switch, and blade engagement interlock are integrated with the controller logic, and any interruption in these circuits should be addressed by tracing the wiring harness and reseating or replacing affected components. Clear labeling on components, along with a service manual revision tag, aids in accurate identification during troubleshooting and ensures that replacements are compatible with the specific unit.

When performing routine maintenance, technicians should document part numbers, service dates, and observed wear for each component. This documentation supports traceability and helps predict replacement timelines based on usage patterns. The nomenclature for fasteners, bushings, and electrical connectors follows standard metric or imperial sizing as indicated on the unit’s labeling, which minimizes the risk of incorrect installations. Special attention should be given to anti-corrosion measures on exposed metal surfaces, as well as the integrity of weatherproof seals around electrical enclosures. Proper torque values and thread locking methods are essential to prevent loosening due to vibration during mowing operations. A methodical approach to inspection and replacement will improve reliability, reduce emergency repairs, and extend the operational life of the SCAG STC48V-22FS.

Installation and setup

The SCAG STC48V-22FS requires careful handling during unpacking to preserve safety and maintain component integrity. Begin by inspecting the shipping container for any signs of damage and verify that all listed items are present according to the packing manifest. Remove each component gently to avoid scratches or dents on critical surfaces, paying special attention to delicate electrical connectors and protective packaging around the battery compartment. Allow the unit to acclimate to the ambient workshop temperature before performing any hookup procedures, as extreme temperature changes can affect battery performance and fuel system behavior. After initial removal, visually inspect all fasteners, mounting brackets, and linkage for signs of loosening or misalignment that may have occurred in transit, and tighten to factory specifications as needed.

With the unit oriented on a stable work surface, perform a systematic exterior inspection to identify any cosmetic or structural damage. Check the chassis rails, wheel assemblies, and deck for warping or deformation, and ensure that all guards and safety shields are correctly seated. Verify that vacuum lines, fuel lines, and electrical harnesses are free from kinks, cracks, or obvious wear. If any damage is found, document it and consult authorized service personnel before proceeding with installation to prevent equipment failure or safety hazards during operation. Maintain a clean work area to reduce the risk of foreign material ingress into the fuel and electrical systems during setup.

Proceed to verify the compatibility of mounting hardware with the mower deck, engine, and powertrain assembly. Confirm that the correct mounting bolts, washers, and spacers are used for each connection and that threads engage cleanly without cross-threading. Fit the control panel, gauge cluster, and starter switch into their designated locations, ensuring secure fastening and proper alignment with interfaces. Reconnect the battery cables using the correct polarity and torque specifications, and inspect the battery hold-down for secure satisfaction of vibration and transport conditions. Replace any protective coverings or insulating materials that were moved or removed during disassembly to preserve electrical isolation and thermal management.

Battery and fuel system setup requires careful attention to safety and regulatory guidelines. Begin with the battery installation, ensuring that the battery terminals are clean and free of corrosion and that the battery is seated firmly in its tray with the proper anti-vibration restraints. Connect the positive and negative cables following the manufacturer’s color-coding and torque recommendations, and verify that all terminal connections are tight and free of oxidation. If the machine uses a removable battery pack, confirm that the pack engages fully with the contact pins and that locking mechanisms are engaged. For the fuel system, inspect the fuel tank for any protective plugs or caps that may be present, and ensure the fuel lines are free from cracks, kinks, or signs of wear. When connecting fuel lines, use fresh clamps and cyclically check for leaks with a suitable non-flammable solvent solution after installation. Take care to purge undiluted fuel vapors in a well-ventilated area before attempting to start the engine.

Tool mounting and compatibility focus on securing all operator and maintenance tools correctly and ensuring that any accessories are compatible with the SCAG STC48V-22FS. Confirm that the bumper, blade drive, and deck mounting tools are compatible with the current model year and regional specifications. When mounting tools such as fuel stabilizers, oil drains, or diagnostic devices, ensure that each item is rated for outdoor power equipment use and that mounting points are not stressed beyond their design limits. Align the tool mounting brackets with the corresponding chassis points, then tighten to the recommended torque values to avoid vibration or fidgeting during operation. Finally, perform a functional check of all active components, including the ignition system, safety interlocks, throttle control, and hydraulic or belt-driven subsystems, to ensure smooth engagement and reliable performance before performing a test run in a controlled environment.

Operation and controls

Starting and stopping procedures require attention to safety and sequence to ensure optimal performance and avoid damage. Prior to starting, verify that the engine has adequate fuel and oil, and that all guards and shields are securely in place. Set the parking brake if equipped, engage the throttle to idle, and ensure the ignition switch is in the off position before performing any pre-start checks. When starting, turn the key or engage the start switch while ensuring the transmission is in neutral or park. If the engine does not start within a few seconds, wait briefly to prevent a flooded condition, then retry with a brief throttle assist as recommended by the manufacturer.

To stop the machine, return the throttle to idle, disengage any attachments, and move the ignition switch to the off position. Allow the engine to cool after shutdown if it has been under heavy load, particularly in hot or humid conditions. Always remove the key and secure the machine when unattended to prevent unauthorized use. For engines with a fuel shutoff valve, close the valve after shutdown to minimize fuel vapor during storage. Conduct a quick visual inspection after stopping to ensure there are no obvious signs of damage or leaks before the next operation.

Basic operation and performance checks begin with a thorough walkaround to confirm all components are intact and free of obstructions. Check tire pressure or track tension, inspect belts for signs of wear, and verify that all safety switches function correctly. Start the engine and observe idle stability, smooth acceleration, and consistent RPM within the specified range. Test the PTO or attachment engagement under light load to confirm proper operation, ensuring that noises, vibrations, or misalignment are not present. Document any deviations and address them before engaging in full working duty to prevent premature wear or safety hazards.

During normal operation, monitor engine temperature, oil pressure, and fuel levels at regular intervals. Listen for unusual noises such as grinding, knocking, or irregular clattering, which may indicate mechanical issues requiring immediate attention. Maintain clean air intake and exhaust pathways to ensure efficient performance, and periodically inspect and replace air filters according to the maintenance schedule. When operating under load, adjust speed and throttle positions to maintain consistent output while preserving fuel economy and minimizing stress on driveline components. End-of-operation cooldown periods may be necessary after heavy or prolonged use to prevent overheating and extend engine life.

Instrumentation and indicators provide at-a-glance feedback on the machine’s status. The digital or analog gauges should show stable readings for RPM, temperature, and oil pressure within their normal operating ranges. Warning lights or audible alerts should be understood and tested during routine checks so that immediate action can be taken if a fault is detected. A maintenance reminder indicator, if present, should be reviewed and reset according to the manufacturer’s procedure after completing service tasks. Familiarize yourself with the owner’s manual for the exact meaning of each indicator and the recommended corrective actions, as misinterpretation can lead to improper responses and potential damage.

In addition to the core indicators, ensure that safety-critical controls such as dead-man handles, blade or attachment engagement levers, and emergency stop mechanisms function correctly. Verify that fuel and coolant fill caps are secure and that any access panels are properly seated to prevent contamination or accidental contact with moving parts. Regular calibration of gauges, if applicable, helps maintain measurement accuracy and system reliability. By understanding and regularly verifying instrumentation and indicators, operators can maintain optimal performance and respond promptly to any deviations that may arise during operation.

Maintenance and troubleshooting for the SCAG STC48V-22FS focuses on establishing a consistent care routine that preserves performance, safety, and reliability. Adhering to a regular maintenance schedule helps prevent unexpected downtime and extends the life of critical components such as drive belts, bearings, and hydraulics. A disciplined approach includes daily visual inspections, weekly functional tests, and monthly parameter verification, all conducted with the engine off and the battery disconnected when appropriate. Maintaining clean air and cooling passages reduces overheating risk, while promptly addressing any signs of excessive vibration or unusual noises can prevent more serious failures down the line. Keeping precise service records supports timely part replacements and facilitates diagnostics during troubleshooting.

Regular maintenance schedule: Create a calendar that aligns with usage intensity, environment, and manufacturer recommendations. The daily routine should include checking fluid levels, inspecting tires or tracks for wear, and verifying that all safety guards are in place and intact. Weekly tasks typically involve inspecting lights, gauges, and warning indicators, as well as testing the brake and steering systems for proper function. Monthly maintenance should address more in-depth items such as changing hydraulic fluid and filters if indicated by service intervals, replacing worn belts, and lubricating pivot points and linkage connections. Adhering to the prescribed service intervals helps maintain optimal performance, reduces the likelihood of unexpected failures, and supports compliance with safety standards.

Common problems and solutions: Many operators encounter stalling or hard-starting conditions that can be traced to fuel system or ignition issues. Start with a thorough inspection of air filters, fuel filters, and spark plugs, replacing components as needed and ensuring there are no air leaks in the intake system. If power loss occurs during operation, verify that the fuel line is clear, the carburetor or fuel injectors are functioning, and the exhaust is not restricted. For hydraulic concerns such as sluggish response or unusual stiffness, check hydraulic fluid levels, purities, and filter condition, and inspect hoses for leaks or kinks. Electrical symptoms like intermittent gauges or startup failures often point to battery health, loose connections, or blown fuses; clean terminals, reseat connectors, and replace failed fuses or worn wiring as required. Document each issue with symptoms, steps taken, and results to support future diagnostic decisions.

Electrical and hydraulic system checks: Begin with a systematic voltage and continuity check of the electrical harnesses, accessories, and control modules, ensuring power is within manufacturer-specified ranges and that grounds are solid. Inspect fuse blocks and relays for signs of overheating or corrosion and replace faulty parts with OEM equivalents to preserve system integrity. For the charging system, verify alternator output and battery condition, performing a load test if available to ensure reliable cranking and operation under load. Hydraulic system checks should cover reservoir levels, cleanliness of hydraulic fluid, and pressure readings at established test points, with attention to any unusual noises, cavitation, or slow response that could indicate internal wear or contamination. When performing these checks, follow all safety procedures, including depressurizing hydraulic circuits and securing components to prevent accidental movement, and record readings to support trend analysis and maintenance planning.

Diagnostics and repair procedures

Diagnostics begin with a systematic assessment of the SCAG STC48V-22FS to identify faults accurately and safely. Start by verifying the machine’s model, serial number, and reported symptoms from the operator, noting any abnormal noises, overheating, loss of electrical power, or unusual vibrations. Ensure the battery state-of-charge, wiring harness integrity, and protective fuses are within manufacturer specifications. Utilizing the on-board diagnostic indicators, record any fault codes and map them to potential subsystems such as the electrical harness, control module, or hydraulic system. A clean, well-lit work area and proper lockout/tagout procedures are essential before disconnecting any electrical connectors or accessing internal components. This initial triage reduces unnecessary disassembly and directs attention to the most probable failure sources.

When flowcharts indicate a fault, follow a structured troubleshooting path that emphasizes safety and repeatability. Confirm power availability to the machine’s control circuits, check for blown fuses, and test continuity across critical harness segments. Use a calibrated multimeter to measure voltage drops and resistance values against service specifications, documenting deviations. For hydraulic related symptoms, inspect fluid levels, filter condition, and evidence of leaks or contamination. If a suspected component is inaccessible, assess external indicators first, such as error LEDs or fault codes, before proceeding to deeper dissembles. A disciplined approach helps prevent cascading damage during diagnostics and ensures repair actions are necessary and sufficient.

Component level disassembly and inspection requires careful planning to preserve fasteners and alignment features. Remove coverings and shieldings to access the primary subsystems, keeping track of mounting hardware and their original orientation. Inspect electrical connectors for corrosion, pin damage, or loose connections, and clean or replace as required using manufacturer-approved contact cleaners and lubricant. For mechanical assemblies, check bearings, gears, linkage rods, and linkages for wear, scoring, or play; measure critical clearances with appropriate gauges and compare them to torque and fit specifications. Document any degraded components and prepare replacement parts with exact part numbers to avoid compatibility issues. After inspection, reassemble using sequence diagrams and verify that fasteners reach the prescribed torque values to maintain structural integrity and safe operation.

Replacement parts and torque specifications are the final critical area for restoring the SCAG STC48V-22FS to service. Source OEM components to ensure compatibility with electrical connectors, seals, and material hardness requirements. Before installation, inspect new parts for shipping damage and verify their dimensions against the service documentation. When fastening, apply the correct torque using calibrated tools and follow the prescribed tightening sequence to avoid misalignment or stress concentrations. For critical fasteners, use thread-locking compounds only if recommended by the manufacturer and limit usage to designated locations. After installation, perform functional tests and, where applicable, leak checks, ensuring no abnormal noises, vibrations, or fluid seepage occur. Maintain a detailed service log that captures part numbers, installation dates, torque values, and test results to support future maintenance and warranty compliance.

Testing and quality assurance are essential to ensure the SCAG STC48V-22FS operates safely, reliably, and as designed. This section outlines practical, repeatable procedures for functional testing, leakage and pressure verification, and safety system verification. Each procedure is intended to be performed after maintenance, repair, or commissioning to confirm that all subsystems respond correctly under typical operating conditions and that performance metrics meet or exceed factory specifications. Adherence to these guidelines helps prevent premature wear, reduces downtime, and supports long-term equipment integrity.

Functional testing procedures require a structured sequence that validates core capabilities before broader use. Begin with a visual inspection to confirm that all connectors, hoses, and fasteners are secure and free of damage. Power up the system within safe operating parameters and observe control responses, including startup sequences, throttle response, and electronic fault indicators. Execute representative load and runtime scenarios to verify that engagement, RPM control, transmission or drive systems, and braking (if applicable) respond promptly and within expected tolerances. Document any deviations, unusual noises, or vibration characteristics, and perform corrective actions or escalate to maintenance as needed. Re-test after adjustments to confirm that the anomalies are resolved and that the system maintains stability across repeated cycles.

Leakage and pressure tests are critical for maintaining the integrity of hydraulic, pneumatic, and fuel systems. After assembly or service, perform a controlled pressure test using appropriate fixtures and safety equipment, monitoring pressure gauges for steadiness and gradual rise without spikes. Inspect seals, gaskets, fittings, and hoses for signs of seepage or dampness, and tighten or replace components as required. For hydraulic systems, verify fluid cleanliness, confirm absence of air pockets, and confirm that relief valves operate within specified pressure ranges. If the machine uses a fuel system, check for leaks at lines, clamps, and injectors, and ensure that the fuel pressure aligns with manufacturer specifications. Record test conditions, ambient temperature, and observed pressures to support traceability and ongoing QA audits.

Safety system verification involves validating all protective features function correctly and reliably in simulated fault conditions. Confirm that emergency stop mechanisms engage promptly and deactivate the system safely when commanded, and test interlocks, guards, and safety switches for proper signaling and lockout behavior. Validate electrical safety features such as overload protection, battery isolation, and short-circuit response, ensuring that fault indicators illuminate and shut down affected subsystems as designed. Conduct tests for braking or retarding systems, if present, under varied load scenarios to ensure predictable and controlled stops. Finally, perform post-test self-check routines and ensure that diagnostic codes reset appropriately after fault resolution, maintaining a clear fault history for future maintenance decisions.

Storage and transport considerations

Proper storage of outdoor power equipment like the SCAG STC48V-22FS is essential to preserve engine health, battery performance, and overall reliability. When storing, ensure the unit is in a clean, dry environment away from sources of moisture, corrosive fumes, and extreme temperatures. Shield the machine from direct sunlight to prevent plastic and rubber components from becoming brittle or warped over time. Regularly inspect for signs of corrosion on metal parts, and apply a light coating of manufacturer-approved lubricant to moving joints to minimize rust formation during periods of inactivity. Elevate the unit on a stable surface to prevent contact with damp floors, which can accelerate moisture ingress into electrical components and the battery area. Clear the area around the equipment of dust and debris, as buildup can compromise cooling pathways and mask hidden damage during longer storage intervals.

For battery-powered models, including the STC48V-22FS, follow the specific manufacturer instructions for battery storage. If batteries are removable, store them with a partial charge in a cool, dry location and avoid exposing them to temperatures outside the recommended range, as extreme heat or cold can degrade capacity and shorten service life. Balance chargers or storage-specific charging routines may be required to maintain battery health, so consult the manual for any required procedures. Never store the machine with a fully discharged battery, as this can lead to sulfation or reduced capacity. Disconnect battery cables if instructed, and store any connectors in a protective manner to prevent stray contact or short circuits.

Transport precautions are critical to prevent damage during handling and to ensure safety on roads or job sites. Before moving the unit, perform a quick pre-transport inspection to secure all moving parts, guards, and attachments, ensuring they are properly fastened and cannot shift during transit. Use appropriate lifting techniques and supports, avoiding sudden impacts that could bend chassis components or displace controls. When loading onto a trailer or truck, secure the machine with high-strength straps or chains rated for the weight of the unit, and position wheel chocks to prevent rolling. If transporting in freezing or hot conditions, protect the equipment from rapid temperature changes by covering sensitive areas as recommended by the manufacturer. For battery models, disconnect any power cables as required and ensure ventilated space during transport to mitigate heat buildup and gas accumulation from vented cells or auxiliary electronics. Check that fuel containers are sealed and stored away from ignition sources if the machine carries fuel-based power, and follow all local regulations regarding fuel containment and spill prevention during transit.

During long-term storage, perform routine checks at defined intervals to catch emerging issues before use. Inspect tires or wheels for flat spots or soft shoulders, and rotate or reposition the unit as needed to prevent deformation from sustained pressure. Verify fluid levels, including engine oil, hydraulic fluid, and coolant where applicable, and replace or top off per the maintenance schedule. Document all storage conditions, including ambient temperature, humidity, and any observed corrosion or leakage, so that a technician can reproduce or analyze the storage environment if service is later required. Finally, keep a visible maintenance log and set reminders for seasonal reconditioning, battery health testing, and battery recharging cycles to ensure the equipment remains ready for operation when needed.

Appendix and reference materials

The appendix consolidates essential reference materials to support accurate maintenance and repair of the SCAG STC48V-22FS. This section includes both parts diagrams and schematics, which provide detailed views of assemblies, fasteners, wiring, and component relationships. Having access to these visuals is critical for correctly identifying replacement parts and understanding how subsystems interact during disassembly and reassembly. When reviewing diagrams, verify revision numbers and cross-reference part numbers with the machine’s serial tag to ensure you source compatible components. Carefully study the diagrams before initiating any repair to minimize downtime and prevent misinterpretation of complex subsystems.

The accompanying schematics offer a concise map of electrical circuits, controls, and safety interlocks. Use these schematics to trace circuits, diagnose faults, and confirm continuity and insulation integrity. It is important to handle electrical schematics with the same caution as the mechanical documentation, ensuring power is isolated and safety procedures are followed during testing. Annotate any deviations observed during service with the corresponding schematic reference so future technicians can easily trace repair history. Keeping a clean, legible record of changes helps maintain traceability and supports warranty considerations when applicable.

The second portion of this appendix covers warranty and service contact information. This material outlines warranty coverage, exclusions, and the process for filing claims, including required documentation and timelines. Record the machine’s model number, serial number, purchase date, and owner details to expedite service requests. Contact information for authorized SCAG distributors and service centers is listed to facilitate prompt escalation if factory guidance is needed. Maintain a log of service events, parts used, and technician notes to support ongoing maintenance and ensure compliance with warranty terms. By keeping these records organized, you can reduce downtime and improve overall machine reliability during peak operating seasons.

For technicians performing field service, ensure you reference the latest revision of diagrams and schematics provided by SCAG. If a discrepancy is found between printed materials and in-machine labeling, defer to the most current official documentation and, when necessary, contact SCAG support for clarification. Always store the appendix materials in a clean, dry, and easily accessible location to support rapid diagnostics and efficient repairs. Proper management of diagrams, schematics, and warranty information enhances service quality, minimizes guesswork, and promotes safe, reliable operation of the SCAG STC48V-22FS.