What does the exclamation mark on the steering wheel indicate as a fault light?
2 Answers
An exclamation mark appearing on the steering wheel indicates the Electronic Power Steering (EPS) warning light, which should disappear immediately after the engine starts. The Electric Power Steering (EPS) system is a power steering system that directly relies on an electric motor to provide auxiliary torque. Compared to the traditional Hydraulic Power Steering (HPS) system, the EPS system offers many advantages. The EPS system mainly consists of a torque sensor, vehicle speed sensor, electric motor, reduction mechanism, and Electronic Control Unit (ECU). The Electric Power Steering system has evolved from the traditional mechanical steering system. It uses the power generated by an electric motor to assist the driver in steering operations. The system primarily consists of three major components: signal sensing devices (including torque sensor, steering angle sensor, and vehicle speed sensor), steering assist mechanism (electric motor, clutch, reduction transmission mechanism), and electronic control device. The electric motor operates only when assistance is needed. When the driver operates the steering wheel, the torque and angle sensor generates corresponding voltage signals based on the input torque and steering angle. The vehicle speed sensor detects the speed signal, and the control unit issues commands to control the motor's operation based on the voltage and speed signals, thereby generating the required steering assistance.
Last time I drove, I also encountered this steering wheel warning light with an exclamation mark, and my heart skipped a beat. Later, I learned that it usually indicates a problem with the power steering system—either the electric power assist has failed or there’s an issue with the mechanical components. I immediately pulled over to check and found the steering wheel as heavy as lifting a rock. When this light is on, steering becomes extremely difficult. There could be many possible causes, such as a faulty steering sensor, a malfunctioning control module, or poor contact in the steering column wiring. In my case, it turned out to be a short circuit in the torque sensor. You really can’t ignore this kind of issue—sudden heavy steering is too dangerous. It’s safer to call a tow truck and head straight to the 4S shop.
