Stiff steering when your 2022 Lexus RX is cold that improves as the vehicle warms up suggests temperature-related effects on the electric power steering system. While some increase in effort is normal in cold conditions, significant stiffness warrants investigation.
Normal Cold Weather Effects
Cold temperatures thicken lubricants throughout the steering system, slightly increasing friction and effort. The EPS motor and electronics also perform differently when cold. Minor increases in steering effort during the first few minutes of driving are normal and expected.
EPS Motor Cold Behavior
Electric power steering motors can provide different assist when cold due to temperature effects on the motor windings and electronics. Some systems deliberately limit assist when first started to protect components. Excessive stiffness or prolonged heavy steering indicates abnormal operation.
Lubricant and Mechanical Issues
Inappropriate lubricants, insufficient lubrication, or worn components can create excessive cold stiffness that exceeds normal temperature effects. These mechanical issues manifest most clearly when cold and may improve as friction generates heat.
Sensor Calibration
The torque sensor that measures your steering input affects assist delivery. Temperature can affect sensor readings—if the sensor reports incorrectly when cold, assist may be reduced. Calibration issues may be more apparent at temperature extremes.
Comparing to Normal
Compare your steering to another RX or to your vehicle's behavior in warmer conditions. If cold steering effort is dramatically higher than normal or takes extended time to improve, a problem likely exists beyond normal temperature effects.
Code C1552 and EPS Control
Code C1552 relates to EPS control or motor issues that may affect cold operation. Temperature-sensitive faults may not set codes until they become consistent across conditions.