Symptom Diagnosis

When a diagnostic code cannot be confirmed or problem cannot be confirmed in appropriate articles find basic symptom;

For example, vehicle engine will not start. Appropriate heading matching vehicle symptom is DOES NOT START. Listed under DOES NOT START are more specific conditions. Find specific condition which best describes vehicle malfunction. Perform checks in order given. DO NOT skip steps.

NOTE: Even if a diagnostic code is not set, this article may refer you to a test procedure for a specific diagnostic code in appropriate articles:

For ES300 TESTS W/CODES - OBD-II

For LS400 TESTS W/CODES - OBD-II

This articles includes trouble shooting for the following symptoms:

Does Not Start
Difficult To Start
Poor Idling
Poor Driveability
Engine Stall