Self-Diagnostic System: Pre-Check: 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.