| 1 | Wheel targets or sensors | Targets, sensor heads, or imaging units attached to the wheels provide position data to the alignment system. | Mounting must be secure and the targets or sensors must be correctly identified by the equipment. |
| 2 | Measurement technology | Systems may use optical cameras, electronic sensors, or other measurement arrangements to determine wheel positions relative to one another. | Measurement method and available functions vary by equipment model; follow the manufacturer's operating procedure. |
| 3 | Runout compensation | Compensation accounts for measurement errors caused by wheel or target mounting variation. Depending on the system, this may involve rolling the vehicle or rotating the wheel. | Complete the specified compensation procedure before relying on alignment readings. |
| 4 | Toe | Toe describes the direction the wheels point when viewed from above: inward is toe-in and outward is toe-out. | Front toe is commonly adjusted at the steering linkage, such as the tie rods, where the vehicle design permits. |
| 5 | Camber | Camber is the inward or outward tilt of a wheel when viewed from the front of the vehicle. | Adjustment availability depends on the suspension design; some vehicles require specific parts or procedures to change it. |
| 6 | Caster | Caster is the forward or rearward tilt of the steering axis when viewed from the side of the vehicle. | It is generally measured during a steering sweep. Adjustment methods and specified values are vehicle-dependent. |
| 7 | Steering-axis inclination | Steering-axis inclination (also called SAI or KPI) describes the inward angle of the steering axis when viewed from the front. | It is typically a diagnostic measurement rather than a direct adjustment; an unexpected reading can indicate a bent or damaged component. |
| 8 | Thrust angle reference | Thrust angle describes the direction in which the rear wheels steer the vehicle relative to its centerline. | Even during a front-wheel alignment, the rear-wheel direction can help technicians center the steering wheel and assess tracking. |
| 9 | Vehicle specification database | The alignment display compares measured angles with the selected vehicle's specified service values. | Select the correct vehicle configuration and consult current service information; specifications can differ by model, trim, and suspension. |
| 10 | Adjustment and final verification | The technician makes permitted adjustments, rechecks the readings, and confirms the steering wheel and alignment values are within the applicable specifications. | Inspect tires, steering, and suspension components as needed; alignment readings alone do not establish that worn or damaged parts are serviceable. |