Check For Intermittent Problems

WARNING: This page is about a different car, the 2008 Lexus LS 600hL. However, it is still accessible from the selected car via links, so may be relevant.

HINT.

Inspect the vehicle's ECM using check mode. Intermittent problems are easier to detect with the intelligent tester or Techstream when the ECM is in check mode. In check mode, the ECM uses 1 trip detection logic, which is more sensitive to malfunctions than normal mode (default), which uses 2 trip detection logic.

Clear the DTCs (see DTC CHECK/CLEAR ).
Switch the ECM from normal mode to check mode using the intelligent tester or Techstream (see CHECK MODE PROCEDURE )
Perform a simulation test.
Check and wiggle the harness(es), connector(s) and terminal(s)