How do you fix electric power steering failure?
Electric power steering (EPS) failures are usually caused by electrical supply problems or faulty sensors rather than a worn steering rack. If you experience a loss of steering assist, safely pull over and have the vehicle diagnosed by a qualified technician.
What is electric power steering?
Electric power steering replaces the hydraulic pump with an electric motor that provides steering assist based on speed and driver input. A steering angle sensor, a torque sensor, and an EPS control module coordinate the amount of assist. When the system detects a fault, it can illuminate a warning light and may restrict assist or enter a limp mode to help you reach a safe stop.
Common causes of EPS failure
Several issues can trigger an EPS warning or a sudden loss of assist. Knowing the typical culprits helps focus diagnosis and repairs.
- Battery or charging system problems, leading to insufficient voltage for the EPS motor
- Faulty steering angle sensor (SAS) or torque sensor, which misreads steering input
- Damaged, corroded, or loose wiring and connectors in the steering column or power supply
- Blown fuses or faulty relays related to the EPS circuit
- Malfunctioning EPS motor or gear assembly
- Water ingress or physical damage from an accident in the steering system
In most cases, electrical or sensor-related problems dominate, while mechanical wear is less common. Accurate diagnosis often requires a specialized scan and voltage checks.
Diagnostic steps you can take
Before committing to expensive repairs, you can perform a conservative diagnostic process to gather information and inform a technician.
- Check for warning lights and read any stored diagnostic trouble codes (DTCs) with an OBD-II scanner that supports manufacturer-specific EPS codes.
- Verify the battery and alternator health. With the engine off, a healthy battery should show about 12.6 volts; with the engine running, charging voltage should typically be 13.8–14.8 volts.
- Inspect fuses and relays related to the EPS and steering system; replace any that are blown or corroded.
- Inspect electrical connectors and wiring around the steering column, EPS motor, and power supply for corrosion, looseness, or damage.
- Review service history for recent software updates or calibrations that affect EPS; some faults are resolved with calibration or software fixes.
- Note when the issue occurs (temperature, speed, steering angle) as this can help distinguish sensor vs. motor problems.
- If you can access service information from the vehicle manufacturer, follow any model-specific diagnostic steps or recall notices related to EPS.
If diagnostic codes point to sensors or the EPS control module, or if tests require specialized equipment, professional service is advised. Correcting wiring faults and performing calibrations typically require a dealer or experienced shop.
What to do if EPS fails while you are driving
EPS failures can be dangerous, especially at higher speeds or in tight maneuvers. Use these safety steps to reduce risk until you can get the car inspected.
- Safely pull over to a stable location as soon as possible and engage hazard lights.
- Turn the engine off, then restart to see if steering assist returns; do not rely on it if the wheel remains heavy or unresponsive.
- Drive only at very low speeds if you must move the vehicle to a safe location, and avoid sharp turns or rapid maneuvers.
- Call roadside assistance or a tow to a qualified service center if steering remains heavy or unresponsive.
Do not attempt DIY fixes while the system is exhibiting a fault. EPS includes a high‑voltage or high‑current electrical loop and sensitive sensors that require proper tools and knowledge to service safely.
Professional repair options
When you seek professional help, technicians will typically diagnose and address the root cause with one or more of the following approaches.
- Repair or replace faulty sensors (steering angle sensor, torque sensor) and recalibrate the system.
- Repair or replace the EPS motor or gear assembly if the motor has failed or stalls.
- Replace or reprogram the EPS control module and apply any available software updates or recalls.
- Repair damaged wiring harnesses, connectors, or grounding points and replace blown fuses/relays.
- Ensure the vehicle’s battery and charging system are healthy; replace the battery or alternator if needed.
In many cases, a software update, sensor recalibration, or replacing a faulty sensor or motor resolves EPS faults. If the component is under warranty, consult the dealer for coverage and coded service notices.
Preventive maintenance and longevity
Regular maintenance can reduce the likelihood of EPS failures and keep steering performance consistent.
- Keep the 12-volt battery in good condition and have the charging system checked during routine service.
- Address warning lights promptly and have codes read at a certified shop rather than ignoring them.
- Avoid exposure to moisture and salt that can corrode electrical connectors around the steering column.
- Install any recommended software updates and follow manufacturer service bulletins for EPS-related issues.
- Have steering components inspected during regular maintenance, especially on older vehicles or after an accident.
A proactive approach to electrical and sensor health can prevent EPS faults from escalating into a safety concern on the road.
Summary
Electric power steering failures are most often electrical or sensor-related problems rather than mechanical wear. Start with a safety-first approach: pull over safely, check the battery and fuses, and obtain a diagnostic code reading. If a fault is found in sensors, control modules, or wiring, professional repair and possible software updates are typically required. Regular maintenance and prompt attention to warning lights can help keep EPS systems reliable and reduce the risk of an unexpected steering failure.
