Engine Controls - Self-Diagnostics: Introduction
CAUTION:
DO NOT crank engine before replacement PCM is programmed to immobilizer system, or PCM will be severely damaged. If test procedures require replacement of PCM on a vehicle equipped with immobilizer system, vehicle must be sent to authorized Mazda dealer to have replacement PCM programed.
NOTE:
Vehicle with immobilizer system can be identified by a solid urethane ignition key head.
Most engine control problems result from mechanical failures, poor electrical connections or damaged vacuum hoses. Before condemning the computer system, perform checks and inspections covered in BASIC DIAGNOSTIC PROCEDURES article. Failure to do so may result in lost diagnostic time.
If no faults were found while performing BASIC DIAGNOSTIC PROCEDURES, proceed with self-diagnostics. If no fault codes are present after entering self-diagnostics, proceed to TROUBLE SHOOTING - NO CODES article for diagnosis by symptom (i.e., ROUGH IDLE, NO START, etc.). If DTC exists, but problem cannot be found or duplicated, problem is intermittent or problem was previously repaired and codes not cleared.