DTC P0604, DTC P0606, DTC P0607 Or DTC P0657: Notes

Code Definitions

• DTC P0604: Internal Control Module Random Access Memory (RAM) Error
• DTC P0606: ECM/PCM Processor
• DTC P0607: Control Module Performance
• DTC P0657: Actuator Supply Voltage Circuit/Open
  NOTE: For information on engine immobilizer system, see COMPUTERIZED ENGINE CONTROLS in THEORY & OPERATION article.
  CAUTION: If ECM replacement is instructed in following testing, always ensure ECM harness connector and ground circuit are okay. If either are suspect, repair and repeat testing to confirm ECM malfunction. If ECM is replaced, ECM must be programmed with proper ignition key code for engine immobilizer system. For programming procedures, see COMPUTER RELEARN PROCEDURES - LEXUS article.