Code No. P0604: Random Access Memory (RAM) Malfunction


FUNCTION



  • The engine-ECU writes information to RAM or reads information from RAM.
  • The engine-ECU performs an initial check to detect errors in RAM.

TROUBLE JUDGMENT


Check Condition
  • Ignition switch is in "ON" position.
Judgment Criterion
  • A destroyed RAM is detected by engine-ECU initial check.

PROBABLE CAUSE



  • Failed engine-ECU

DIAGNOSIS PROCEDURE

STEP 1. M.U.T.-III diagnosis code

  • After erasing the diagnosis code through M.U.T.-III, ignition switch is "ON" position and confirm whether the diagnosis code is output.

Q. Is the diagnosis code set?
Replace the engine-ECU. When the engine-ECU is replaced, write the chassis number (Refer to GROUP 00 - Precautions Before Service - How to Perform Chassis Number Writing ). After replacing the engine-ECU, register the injector identification code and learn fuel injection (Refer to GROUP 00 - Precautions Before Service - What The Common Rail Engine Learns ). After registering the injector identification code, the vehicle equipped with the DPF carries out the forcible DPF regeneration. (Refer to GROUP 17 - Emission Control - Diesel Particulate Filter (DPF) System - Forcible DPF Regeneration ).
Intermittent malfunction (Refer to GROUP 00 - How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunctions ).