DTC P1633: Engine Control Module Malfunction (Electronic Throttle Control System Circuit): Notes

WARNING: Read service precautions before proceeding with service procedure. See SERVICE PRECAUTIONS .

CAUTION: If Engine Control Module (ECM) replacement is instructed in following test, always ensure ECM connectors and ground circuits are okay. If either are defective, repair and repeat testing to confirm ECM malfunction. On models equipped with engine immobilizer, if ECM is replaced, ECM must be programmed with proper ignition key code for engine immobilizer system. For programming procedures, see COMPUTER RELEARN PROCEDURES - TOYOTA article in GENERAL INFORMATION, or appropriate ENGINE IMMOBILIZER SYSTEMS article in ACCESSORIES & EQUIPMENT.