Retrieving Diagnostic Trouble Codes

WARNING: This page is about a different car, the 2002 Lexus ES 300. However, it is still accessible from the selected car via links, so may be relevant.

On all models, trouble codes are a 4-digit code. See DIAGNOSTIC TROUBLE CODE INDEX table. DTCs can only be retrieved using Lexus Scan Tool or On-Board Diagnostic (OBD-II) scan tool that complies with SAE standard J-1978. Connect scan tool to 16-pin Data Link Connector (DLC3). See Fig 1. DLC3 is located under instrument panel, near steering column. See Fig 2. When trouble code is present, Malfunction Indicator Light (MIL) located on instrument panel will light. To retrieve trouble codes using scan tool, follow scan tool manufacturer's operating instructions.

If no trouble codes exist, perform manual shift test to determine if problem area is in electrical circuits or a mechanical transaxle problem. See MANUAL SHIFT TEST under PERFORMANCE TESTS.

NOTE: When 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.

NOTE: Scan tool or OBD-II scan tool may be operated in NORMAL mode when retrieving trouble codes. Only Lexus Scan Tool can be used in CHECK mode when retrieving DTCs.

NORMAL mode is used to retrieve DTCs from ECT ECU. 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. CHECK mode helps determine malfunctions caused by poor electrical connections, which are difficult to determine using NORMAL mode.

NOTE: Once repairs have been performed, codes must be cleared from ECM memory. See CLEARING DIAGNOSTIC TROUBLE CODES .

Fig 1: Identifying Data Link Connector Terminals

Fig 2: Connecting Scan Tool To Data Link Connector