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.

FAIL-SAFE AND BACKUP FUNCTION



  • The engine is stopped (The fuel injection and pump pressure feed are stopped).
  • The DPF regeneration is prohibited.
  • The throttle valve is opened (Electrical discontinuity).
  • The EGR control is stopped (fully closed).
  • The AS&G control is prohibited.

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 set.

Q. Is the diagnosis code set?
Replace the engine-ECU.
Intermittent malfunction (Refer to GROUP 00 - How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunctions ).