If steering assistance is suddenly lost while driving, the vehicle should be inspected immediately, as increased steering effort can significantly affect vehicle control and safety. Regular battery maintenance, electrical system inspections, and prompt diagnosis of warning lights can help prevent major EPS failures and extend the service life of the electric power steering system.
How to Fix Electric Power Steering Problems - Step 1: Check the Battery and Charging System
Low system voltage is one of the most common causes of EPS malfunctions.
Measure battery voltage with the engine off; it should typically be around 12.6 volts.
Check charging voltage with the engine running; most vehicles require 13.5–14.8 volts.
Inspect battery terminals for corrosion or loose connections.
Test the alternator for proper output.
A weak battery or failing alternator can trigger EPS warning lights and disable steering assistance.
Step 2: Scan for Diagnostic Trouble Codes (DTCs)
Use a professional scan tool capable of communicating with the EPS module.
Common EPS-related fault codes may indicate:
Steering torque sensor failure
Steering angle sensor malfunction
Motor circuit faults
Power supply issues
Communication errors between control modules
Reading fault codes helps identify the affected component before unnecessary parts replacement.
Step 3: Inspect Fuses and Wiring
Electric power steering systems require stable electrical power.
Check for:
Blown EPS fuses
Damaged wiring harnesses
Loose ground connections
Corroded electrical connectors
Water intrusion near the steering rack or control module
Many EPS failures are caused by wiring damage rather than defective steering components.
Step 4: Verify Steering Angle Sensor Operation
The steering angle sensor monitors steering wheel position and communicates with multiple vehicle systems.
Symptoms of a faulty sensor include:
EPS warning light
Stability control warnings
Off-center steering wheel
Inconsistent steering assistance
In many cases, sensor recalibration with a diagnostic tool can restore proper operation after wheel alignment or suspension repairs.
Step 5: Test the Torque Sensor
The torque sensor detects the driver's steering input and determines how much assist the motor should provide.
A defective torque sensor may cause:
Sudden loss of assist
Uneven steering effort
Steering that feels too light or too heavy
EPS fault codes
Some vehicles allow sensor replacement, while others require replacement of the steering column or steering rack assembly.
Step 6: Inspect the EPS Motor
The electric assist motor can wear out over time due to heat, vibration, and high mileage.
Signs of motor failure include:
Complete loss of steering assist
Grinding or whining noises
Intermittent operation
Overheating-related shutdowns
Motor testing should include checking power supply, ground circuits, and motor current draw.
Step 7: Check the EPS Control Module
The EPS Electronic Control Unit (ECU) processes information from sensors and controls motor operation.
Possible issues include:
Internal circuit failure
Software corruption
Communication network faults
Water or moisture damage
Some manufacturers provide software updates that correct steering performance issues without replacing hardware.
Step 8: Perform Steering System Calibration
After replacing EPS components, wheel alignment, steering racks, or sensors, recalibration may be necessary.
Common procedures include:
Steering angle sensor reset
Torque sensor calibration
EPS module initialization
Wheel alignment verification
Failure to perform calibration can result in warning lights and improper steering assist.