What is the reason why the car steering wheel cannot return to its position automatically?

The steering wheel may not return to its position automatically due to several common issues. The most likely causes include misaligned wheel alignment, low power steering fluid, worn steering components, or incorrect tyre pressure.

1. Wheel alignment issues: If the wheels are misaligned, the steering system struggles to self-centre. A professional alignment check can resolve this.
2. Low power steering fluid: Insufficient fluid reduces hydraulic assistance, making the steering feel heavy and preventing automatic return. Check the fluid level and top up if necessary.
3. Worn steering components: Damaged tie rods, ball joints, or bushings can hinder smooth movement. A mechanic should inspect these parts.
4. Incorrect tyre pressure: Uneven pressure affects steering response. Ensure all tyres are inflated to the manufacturer’s recommended levels.

For electric power steering (EPS) systems, faults in the control unit or sensors may also cause this issue. Models like the Ford Focus or Vauxhall Corsa with EPS should be diagnosed using specialised tools. If basic checks don’t solve the problem, consult a professional to avoid safety risks.

The reasons why the car steering wheel cannot return to its position automatically include low tire pressure, inaccurate adjustment of the hydraulic power system control valve, and the steering wheel being locked when starting the car.

Low tire pressure, misalignment of the front wheels, or incorrect camber angle can be adjusted. It could also be due to inaccurate adjustment of the hydraulic power system control valve, or the hydraulic valve being stuck or clogged with dirt. It is recommended to go to a 4S shop for maintenance. If the steering wheel is locked when starting the car, the owner should gently turn the key with the right hand and lightly rotate the steering wheel with the left hand, and the steering wheel will naturally unlock. This situation does not occur every time the car is started. Generally, after starting the car with the key, the steering wheel will automatically unlock. However, sometimes when parking, the steering wheel is placed at a certain angle, and this angle happens to be such that turning the key to start the car does not unlock the steering wheel, resulting in the steering wheel being locked.

Introduction to automatic return:

Automatic return is specifically designed to increase the car's handling and driving stability. The determining factors are the caster angle and the kingpin inclination angle, with the caster angle having the greatest impact. The perceived return force is due to the caster angle. Nowadays, the front wheels of cars are all independent suspensions, so there is no physical kingpin, just a virtual line. The rotation of the wheels is based on an axis, rotating around this axis, which is called the kingpin. For most cars, the line connecting the upper support point of the shock absorber and the lower control arm support point is the kingpin line. This line is not perpendicular to the ground at the center of the wheel; it tilts backward and inward. Tilting backward is called the caster angle, and tilting inward is called the kingpin inclination angle.

From a mechanic’s perspective, the steering wheel’s failure to self-centre often points to mechanical wear. Worn track rod ends or suspension bushes create excess play, disrupting the steering geometry. Another culprit could be a seized steering column universal joint, common in older cars. A quick test: lift the front wheels and check for stiffness when turning. If resistance is felt, lubrication or part replacement is likely needed.