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 codes are stored in NORMAL mode, Lexus scan tool may be used in CHECK mode to determine if any first trip DTCs are stored. OBD-II scan tools that comply with SAE standard J-1979 may be used in MODE 7 (CONTINUOUS TEST RESULTS function) to determine if any first trip DTCs are stored. NORMAL mode is used to retrieve DTCs from Engine Control Module (ECM). MODE 7 or CHECK mode is used to check for DTCs when operating vehicle to simulate conditions in which DTC was set. CHECK mode contains a higher sensing ability to detect malfunctions and helps locate problems caused by poor electrical connections, which are difficult to determine using NORMAL mode.

NOTE: If using Lexus scan tool, when 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.

When to See a Mechanic

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

• You smell fuel, burning insulation, or see smoke.

• Brakes feel soft, pull hard to one side, or make grinding noises.

• The engine overheats, stalls repeatedly, or misfires under load.

• You are missing required tools, torque specs, or safe lifting equipment.

• You are not confident in the next step or safety outcome.

Safety Warning

Retrieving Diagnostic Trouble Codes: Notes

Use the Manual With the Right Hardware

When to See a Mechanic

Rather have a pro handle this?