1993 Lexus SC 300 AutomaticFACTORY OEM SERVICE PROCEDURE

Momentary Interruption Test

If Code 13, 22, 24, 41 or 47 is stored in ECM memory during diagnosis and no trouble can be found with these circuits, perform MOMENTARY INTERRUPTION TEST.

  1. Clear codes from ECM memory. See CLEARING CODESΒ . With ignition off, connect a jumper wire between terminals E1 and TE2 of DLCs No. 1 or 2.
  2. Start engine. Ensure MIL goes out. Pull lightly on wires, and apply vibration to connectors and relays associated with diagnostic code that is set.
  3. If MIL illuminates during this test, a fault is in indicated connector or location in wiring harness. Repair as necessary.
  4. Clear diagnostic codes. Start engine. If MIL does not go out, check thoroughly for faulty connections. Perform MOMENTARY INTERRUPTION TEST again. If MIL still will not go out, check and replace ECM as necessary. See CONTROL UNIT under COMPUTERIZED ENGINE CONTROLS in appropriate I - SYS/COMP TESTS article.
NOTE: Electronically Controlled Transaxle/Transmission (ECT) uses same ECM as EFI system.
Factory Service Tools

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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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