There are 1 owner-reported fuel system complaints for the 2009 Lexus ISin NHTSA's database. These are unverified consumer reports and may not reflect confirmed defects.
AT APPROXIMATELY 85K TOTAL MILES, IS250 AUTOMATIC BEGAN DROPPING FROM 5-6K RPM TO 2-3K RPM WHENEVER CHANGING ROAD GRADE TO AN INCLINE OR DECLINE, USUALLY ABOVE 50 MPH, DROPPING TO 35 MPH ON THE HIGHWAY. TO MAINTAIN PROPER SPEED, I WOULD HAVE TO DOWNSHIFT FROM D TO S AND FLOOR THE ACCELERATOR. TRACTION CONTROL, PARKING BRAKE, AND ABS LIGHTS WOULD SOMETIMES COINCIDE WITH THIS PROBLEM. THIS CONTINUED UNTIL I SOLD THE IS250 AT 88K MILES.
Complaints are unverified consumer reports submitted to NHTSA. A high complaint count may reflect vehicle popularity, not defect severity. Data sourced from NHTSA public records.
Data synced from NHTSA on Apr 25, 2026