Engine Controls - Tests W/Codes - 1.5L: Introduction

Most engine control problems are the result of mechanical breakdowns, poor electrical connections, or damaged vacuum hoses. Before considering the computer system as a possible cause of problems, perform checks and inspections covered in BASIC TESTING - 1.5L article. Failure to do so may result in lost diagnostic time.

If no faults were found while performing BASIC TESTING - 1.5L, proceed with self-diagnostics. If no fault codes, or only pass codes, exist after entering self-diagnostics, proceed to TESTS W/O CODES - 1.5L article for diagnosis by symptom (i.e., ROUGH IDLE, NO START, etc.).