1993 Lexus SC 300 AutomaticFACTORY OEM SERVICE PROCEDURE

Code 52

Condition is: no knock sensor signal to ECM for 4 crank revolutions with engine speed 1600-5200 RPM. Probable cause: open or short in knock sensor circuit (left bank on ES300 or front sensor on GS300 and SC300), loose knock sensor or defective ECM.

Factory Service Tools

Use the Manual With the Right Hardware

Pair factory procedures with proven DIY tools so the instructions are easier to execute.

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When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

  • β€’ You smell fuel, burning insulation, or see smoke.
  • β€’ Brakes feel soft, pull hard to one side, or make grinding noises.
  • β€’ The engine overheats, stalls repeatedly, or misfires under load.
  • β€’ You are missing required tools, torque specs, or safe lifting equipment.
  • β€’ You are not confident in the next step or safety outcome.

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