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Home >> Toyota >> 2013 >> Prius Plug-in >> Repair and Diagnosis >> Steering >> Manual Steering >> Power Steering System (Diagnostics - Introduction) (Plug-In) >> Power Steering System >> Problem Symptoms Table >> Problem Symptoms Table
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Problem Symptoms Table

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POWER STEERING SYSTEM

Symptom Suspected Area Refer to
Heavy steering Front tires (improperly inflated, unevenly worn) Refer to INSPECTION
Front wheel alignment (incorrect) Refer to ADJUSTMENT
Front suspension (lower ball joint) Refer to INSPECTION
Steering post assembly Refer to INSPECTION
Torque sensor (built into steering post assembly) -
Power steering motor -
Speed sensor circuit Refer to DIAGNOSTIC TROUBLE CODE CHART
Auxiliary battery and power source system -
Power steering ECU assembly power source voltage and relay Refer to TERMINALS OF ECU 
Power steering ECU assembly Refer to REMOVAL
Steering effort differs between turning right and left, or steering effort is uneven. Front tires (improperly inflated, unevenly worn) Refer to INSPECTION
Front wheel alignment (incorrect) Refer to ADJUSTMENT
Front suspension (lower ball joint) Refer to INSPECTION
Steering gear assembly Refer to INSPECTION
Torque sensor (built into steering post assembly) -
Steering post assembly Refer to INSPECTION
Power steering motor -
Power steering ECU assembly Refer to REMOVAL
While driving, steering effort does not change in accordance with vehicle speed or the steering wheel does not return properly. Front suspension (lower ball joint) Refer to INSPECTION
Speed sensor circuit Refer to DIAGNOSTIC TROUBLE CODE CHART
Torque sensor (built into steering post assembly) -
Power steering motor -
Power steering ECU assembly Refer to REMOVAL
CAN communication system Refer to HOW TO PROCEED WITH TROUBLESHOOTING
A knocking (or clunking) sound occurs when turning the steering wheel back and forth while power steering is operating. Front suspension (lower ball joint) Refer to INSPECTION
Steering intermediate shaft -
Power steering ECU assembly Refer to REMOVAL
Noise occurs when turning the steering wheel during low-speed driving. Steering gear assembly Refer to INSPECTION
Steering post assembly Refer to REMOVAL
Friction occurs when turning the steering wheel during low-speed driving. Power steering motor -
Steering post assembly Refer to INSPECTION
A high-pitched sound (squeaking) occurs when turning the steering wheel slowly with the vehicle stopped. Power steering motor -
The steering wheel vibrates and noise occurs when turning the steering wheel from lock to lock with the vehicle stopped. Steering gear assembly Refer to INSPECTION
Steering post assembly Refer to INSPECTION
DTCs cannot be output (Terminals TC and CG of the DLC3 are connected) TC and CG terminal circuit Refer to TC and CG Terminal Circuit
IG power source circuit Refer to DTC C1551/51: IG Power Supply Voltage Malfunction
Combination meter Refer to HOW TO PROCEED WITH TROUBLESHOOTING
Sensor check cannot be done (Terminals TS and CG of the DLC3 are connected) TS and CG terminal circuit Refer to TS and CG Terminal Circuit
Power steering ECU assembly Refer to REMOVAL
EPS warning light remains on. EPS warning light circuit Refer to EPS Warning Light Circuit