How to tell if electric power steering is bad?

Electric power steering (EPS) problems often manifest as a steering wheel that’s harder to turn, a warning light on the dash, or unusual steering feel. EPS relies on an electric motor, sensors, and a control module, and issues can stem from the motor, sensors, wiring, or a weak battery. If you notice any of the following signs, have the system inspected promptly to avoid a loss of steering assist.

Recognizing the signs

Common symptoms you may notice on the road include:

• The steering wheel feels hard to turn, especially at low speeds like when parking or maneuvering:


• The steering feels heavy, unresponsive, or inconsistent at times;


• A warning light on the dash for Power Steering, EPS, or steering system lights up;


• Unusual noises such as whining, squealing, or clunking from near the steering column;


• The steering wheel vibrates, shimmies, or feels loose or sloppy;


• Steering response is erratic or the assist seems to come and go without warning.

Observing one or more of these signs warrants a professional diagnostic, as continued use could compromise control in critical moments.

Common causes of EPS failure

EPS failures usually stem from one or more of the following:

• Failing or damaged electric motor or windings;


• Defective torque sensor, steering angle sensor, or related control hardware;


• Damaged or corroded electrical connectors or wiring harness to the EPS motor or sensors;


• Low battery voltage or charging system issues that reduce the EPS’s available power;


• Software problems or calibration needs that require dealer tools or updates;


• Physical damage from a collision or water ingress;


• Intermittent electrical interference or ground faults that affect the EPS controller.

Because EPS is intertwined with the vehicle’s electrical system, diagnosing the root cause often requires a professional scan and inspection of both hardware and software.

Diagnosing EPS problems: what to do

Here is a practical, safety-conscious approach to verifying EPS problems and deciding on next steps.

1. Check the dash for warning lights and note any fault codes shown by an onboard scanner or service tool.


2. Test steering behavior in a safe, controlled area: note when assist is available, reduced, or intermittent, and whether it changes with speed.


3. Inspect the battery and charging system: ensure the battery is healthy (roughly 12.6 volts or higher with engine off) and the alternator is charging (typically 13.5–14.5 volts with engine running).


4. Inspect fuses and electrical connectors related to EPS and verify the wiring to the steering column and motor is intact and clean.


5. Use an appropriate diagnostic tool to pull EPS-related diagnostic trouble codes (DTCs); not all EPS issues generate codes, but many do.


6. If no obvious issue is found, have a technician check steering angle sensor calibration and motor operation with OEM software/tools; some systems require recalibration after wheel removal, battery disconnect, or certain repairs.


7. Refer to the vehicle’s service manual or a qualified technician for advanced testing and remediation, especially if the problem persists after basic checks.

In general, professional diagnosis is essential because many EPS faults are electrical or software-based and may require specialized tools and procedures.

What to do if EPS fails while driving

Immediate safety-focused steps can reduce risk if you experience a sudden loss of steering assist.

• Keep a firm grip on the wheel with both hands and reduce speed gradually, using the vehicle’s normal steering inputs.


• Move to a safe location or shoulder if you can, avoiding heavy traffic or high-speed maneuvering.


• Turn off and then restart the engine to see if the system resets; if assist returns only intermittently or not at all, do not continue driving long distances.


• Contact roadside assistance or a tow to a repair facility; driving with a suspected EPS fault can compromise control in emergency situations.

Note: Some vehicles may regain limited assist after a restart, but this is not reliable. Treat any EPS fault as a potential safety issue requiring service.

Maintenance tips to prevent EPS problems

While not all EPS failures are preventable, you can reduce risk by preserving electrical health and staying on top of routine checks.

• Keep the battery and charging system in good condition; replace weak batteries promptly and address parasitic drains that can drop voltage.


• Avoid rough steering or hitting curbs; address alignment or suspension issues promptly to prevent added load on the steering system.


• Check for recalls and software updates with the dealer; some EPS concerns have been addressed through firmware revisions or service campaigns.


• Have electrical connections to the EPS motor and steering angle sensor inspected during regular service intervals and clean or replace corroded connectors as needed.

Maintaining electrical health, applying timely software updates, and addressing issues early can extend EPS life and improve reliability.

Summary

Electric power steering problems range from inconvenient to potentially dangerous if left unattended. Key warning signs include a hard-to-turn wheel, warning lights, unusual noises, and inconsistent steering feel. A combination of symptom review, battery/charging checks, diagnostic scanning, and professional calibration or repair is usually required to determine the cause and restore safe steering. Always prioritize safety—if EPS fault cues appear while driving, seek professional service promptly and check for recalls or updates that may address known issues.