P0604

DTC P0604 INTERNAL CONTROL MODULE RANDOM ACCESS MEMORY(RAM) ERROR

1. OUTLINE OF DIAGNOSIS
Detect the function abnormality of the microcomputer (RAM). Judge NG when either the main CPU normal RAM or sub CPU normal RAM is abnormal. Judge OK when both of them are normal. At initial routine, write the data to all area of RAM. Judge OK when same data can be read out, and judge NG when same data cannot be read out.




2. ENABLE CONDITION
Perform the diagnosis in the initial routine.

3. GENERAL DRIVING CYCLE
Perform the diagnosis immediately after IG key SW is turned ON.

4. DIAGNOSTIC METHOD




- Abnormality Judgment
Judge NG when the malfunction criteria below are completed.




- Normality Judgment
Judge NG when the malfunction criteria below are completed.

5. DTC CLEAR CONDITION
- When the OK idling cycle was completed 40 times in a row
- When "Clear Memory" was performed

6. MALFUNCTION INDICATOR LIGHT CLEAR CONDITION
- When the OK driving cycle was completed 3 times in a row
- When "Clear Memory" was performed

7. FAIL SAFE
None

8. ECM OPERATION AT DTC SETTING
Memorize the freeze frame data. (For test mode $02)