DTC    P0604    Random Access Memory (RAM)

for Preparation Click here


MONITOR DESCRIPTION

The ECM continuously monitors its internal memory status. This self-check ensures that the ECM is functioning properly. It is diagnosed by internal "mirroring" of the main CPU and sub CPU to detect Random Access Memory (RAM) errors. If outputs from these CPUs are different and deviate from the standards, the ECM will illuminate the MIL and set the DTC immediately.

DTC No.
DTC Detection Condition
Trouble Area
P0604
ECM RAM errors (Main CPU and sub CPU mirroring failure) (1 trip detection logic).
ECM

MONITOR STRATEGY


Required sensors/Components (Main)
ECM
Frequency of operation
Continuous

CONFIRMATION DRIVING PATTERN

  1. Turn the power switch off.
  2. Disconnect the cable from the negative (-) auxiliary battery terminal and wait for 1 minute.
  3. Connect the cable to the negative (-) auxiliary battery terminal.
  4. Turn the power switch on (IG) and wait for 16 seconds or more.

INSPECTION PROCEDURE

NOTICE:
After turning the power switch off, waiting time may be required before disconnecting the cable from the negative (-) auxiliary battery terminal. Therefore, make sure to read the disconnecting the cable from the negative (-) auxiliary battery terminal notices before proceeding with work (Click here).

HINT:
Read freeze frame data using the intelligent tester. The ECM records vehicle and driving condition information as freeze frame data the moment a DTC is stored. When troubleshooting, freeze frame data can be helpful in determining whether the vehicle was running or stopped, whether the engine was warmed up or not, whether the air fuel ratio was lean or rich, as well as other data recorded at the time of a malfunction.

1.READ OUTPUT DTC (DTC P0604)

  1. Connect the intelligent tester to the DLC3.

  1. Turn the power switch on (IG).

  1. Turn the tester on.

  1. Clear the DTCs (Click here).

  1. Turn the power switch off and turn the tester off.

  1. Disconnect the tester.

  1. Disconnect the cable from the negative (-) auxiliary battery terminal and wait for 1 minute.

  1. Connect the cable to the negative (-) auxiliary battery terminal.

  1. Connect the tester to the DLC3.

  1. Turn the power switch on (IG).

  1. Turn the tester on.

  1. Wait 16 seconds or more.

  1. Enter the following menus: Powertrain / Engine and ECT / DTC.

  1. Read the DTCs.
    Result 
    Result
    		Proceed to
    DTC is not output
    		A
    DTC P0604 is output
    		B



B
REPLACE ECM (Click here)
A

CHECK FOR INTERMITTENT PROBLEMS (Click here)