Automatic Transaxle System > Automatic Transaxle System > Troubleshooting > P0604 Internal Control Module Random Access Memory (RAM) Error

Component Location

General Description

This method is for fault detection in order to maintain for optimum condition.

DTC Description

TCU set this code, When input data is not available or ROM I.D is changed.

DTC Detecting Condition

Item

Detecting Condition

Possible cause

DTC Strategy

•	Check the communication

•

TCM

Enable Conditions

•	"IG KEY" ON

Threshold value

•	When the Detected abnormal data from RAM

Diagnostic Time

•	Detected more than 1time

Fail Safe

•	Locked in 3rd gear

Component Inspection

1.	Ignition "ON" & Engine "OFF".

2.	Connect scan tool and select "Diagnostic Trouble Codes(DTCs)" mode.

3.	Using a scantool, Clear DTC.

4.	IG OFF ↔ IG ON (Repeat 2~3times),and then Monitor the "DTC"

Is DTC Re-displayed?

	▶ Substitute with a known-good PCM/TCM and check for proper operation. If the problem is corrected, replace PCM/TCM as necessary and then go to "Verification of Vehicle Repair" procedure.
	▶ Fault is intermittent caused by poor contact in the sensor's and/or TCM(PCM)'s connector or was repaired andTCM(PCM) memory was not cleared. And Go to Component Inspection procedure.

NOTE)

When replacing the TCU, must perform the N position learning and the Initial learning. (refer to Troubleshooting's 'How to perform N position learning' and 'How to perform initial learning')

Verification of Vehicle Repair

After a repair, it is essential to verify that the fault has been corrected.

1.	Connect scan tool and select "Diagnostic Trouble Codes(DTCs)" mode

2.	Using a scantool, Clear DTC.

3.	Operate the vehicle within DTC Enable conditions in General information.

Are you DTCs present?

	▶ Go to the applicable troubleshooting procedure.
	▶ System performing to specification at this time.