Self-Diagnostic System: Pre-Check: Notes

2004 Toyota Celica GT, StandardSECTION Notes
WARNING: This page is about a different car, the 2003 Lexus ES 300 and 2002 Lexus ES 300. However, it is still accessible from the selected car via links, so may be relevant.
NOTE: Before performing pre-check, ensure battery voltage is 10-14 volts. Replace battery and/or repair power feed circuits as necessary.

Pre-check confirms that the diagnostic system is functional and able to identify faults in the system. Two components must be checked to ensure diagnostic system is functional: Body ECU and OPEN DOOR indicator light. Test the body ECU first, then the OPEN DOOR indicator light.

RENDER: 1.0x

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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.