When your 2015 Chevrolet Impala loses power steering assist—the steering becomes heavy and difficult—the Electric Power Steering (EPS) system has detected a fault or experienced a failure. Understanding how EPS works helps diagnose and resolve the issue.
Electric Power Steering Overview
The 2015 Impala uses Electric Power Steering rather than traditional hydraulic power steering. An electric motor mounted on the steering column or rack provides assist based on vehicle speed and steering input. This system is more efficient but relies on electronics that can fail.
Common Failure Causes
The EPS motor can fail, providing no assist. The torque sensor that detects steering input may malfunction. Control module failures prevent proper assist calculation. Wiring issues between components disrupt communication. Low system voltage from a weak battery affects EPS operation. Software glitches can cause intermittent failures.
Warning Signs
A "Service Power Steering" or "Power Steering Assist Reduced" message appears on the dash. The steering wheel becomes noticeably heavier to turn. Steering assist may come and go intermittently. The warning may appear only during certain conditions (turning, parking, etc.).
Diagnostic Steps
Scan for DTCs in the EPS module—codes identify specific component failures. Test battery voltage—EPS systems require adequate voltage to function. Check the fuse for the EPS system. Inspect wiring connections at the EPS motor and control module. If the problem is intermittent, note conditions when it occurs.
Repair Costs
EPS motor replacement costs $500-$1,000 including parts and labor. Torque sensor replacement varies from $300-$600. Control module replacement and programming runs $400-$800. Wiring repairs depend on extent but typically $100-$300. Some issues may be covered by recalls or extended warranties—check with GM.