Retrieving Diagnostic Trouble Codes: Notes

Diagnostic Trouble Codes (DTCs) may be retrieved using Lexus scan tool or On-Board Diagnostic (OBD-II) scan tool that complies with SAE standard J-1978. Lexus scan tool or OBD-II scan tool may be operated in NORMAL mode when retrieving trouble codes. If no DTCs are retrieved in NORMAL mode, Lexus scan tool may be operated in CHECK mode, or OBD-II J1979-compliant scan tool may be used in CONTINUOUS TEST RESULTS function under MODE 7 to observe current data. For aftermarket scan tool, see owner's manual for instructions.

NORMAL mode is used to retrieve DTCs from Engine Control Module (ECM). CHECK mode (or CONTINUOUS TEST RESULTS function under MODE 7) is used to check for DTCs when operating vehicle to simulate conditions in which DTC was set, and contains a higher sensing ability to detect malfunctions. It is also useful to help determine malfunctions caused by poor electrical connections, which are difficult to determine using NORMAL mode.

NOTE: If using Lexus scan tool, when ignition is turned from ON to ACC or OFF position, or scan tool is switched from NORMAL mode to CHECK mode, all DTCs and freeze-frame data will be erased. DO NOT switch modes until all DTCs and freeze-frame data are recorded.