Check For Intermittent Problems

WARNING: This page is about a different car, the 2004 Lexus ES 330. However, it is still accessible from the selected car via links, so may be relevant.

HINT: Hand-held tester only:

Inspect the vehicle's ECM using check mode. Intermittent problems are easier to detect when the ECM is in check mode with a hand-held tester. In check mode, the ECM uses 1 trip detection logic, which has a higher sensitivity to malfunctions than normal mode (default) using 2 trip detection logic.

Clear the DTCs (see DTC CHECK/CLEAR ).
Set the check mode (see CHECK MODE PROCEDURE ).
Perform a simulation test (see HOW TO PROCEED WITH TROUBLESHOOTING ).
Check the connector and terminal (see ELECTRONIC CIRCUIT INSPECTION PROCEDURE ).
Wiggle the harness and connector (see ELECTRONIC CIRCUIT INSPECTION PROCEDURE ).