Why Does Electric Power Steering Become Heavier?
3 Answers
Electronic power steering becoming heavier can be due to the following reasons: 1. Excessive tightness between the rolling bearings and sliding bearings connected to the steering system: This can reduce the lubrication effect of the bearings, causing sticking, which is reflected in the steering wheel's performance. 2. The pump pressure of the power steering pump does not meet the standard value: A heavy feeling may occur when using the steering wheel. Check the flow control valve. During driving, leaks in the flow control valve or safety valve can be repaired by grinding, and then check if the spring of the safety valve has failed. 3. Low hydraulic pressure in the power steering gear: If the steering wheel becomes heavy due to low hydraulic pressure in the steering gear, it is necessary to promptly visit a repair shop for maintenance. 4. Long-term lack of maintenance or untimely replacement of the return oil filter in the oil reservoir: This can lead to poor circulation of the power steering fluid, making the steering wheel heavy.
During my last road trip, I suddenly felt like the steering wheel was filled with lead. After checking for a long time, I found out it was due to low tire pressure increasing resistance. Actually, electric power steering becoming heavy is usually caused by these issues: poor contact of the torque sensor under the steering wheel, like when my car had a milk tea spill before, causing it to stick; worn carbon brushes in the electric power steering motor or loose wiring connections, which is especially noticeable on rainy days; unstable power supply to the vehicle's computer module, aging battery or slipping alternator belt can cause voltage to drop below 10V; tire issues, a difference of 0.5 bar in tire pressure can completely change the steering feel; or it could be electronic limit data confusion, requiring a diagnostic tool to reset. I later kept a portable tire pressure gauge to check anytime.
Our fleet mechanics often encounter this type of fault. During actual repairs, a hierarchical troubleshooting approach should be adopted: First, check the power supply system. After starting the vehicle, measure the voltage at the motor connector. If it's below 12V, inspect the fuse and ground wire. Then, turn the steering wheel and listen to the gearbox—unusual noises may indicate wear in the reduction mechanism. Next, read the data stream from the steering angle sensor; if the deviation exceeds 5 degrees, calibration is required. Don’t forget to inspect the universal joint on the steering column, as rust and sticking can increase the force required by 30%. During a winter rescue operation once, it was found that the issue was caused by a frozen sensor, which was resolved by thawing it with a heat gun. It is recommended to perform anti-oxidation treatment on the steering gear wiring connectors every 20,000 kilometers.
