Sub ROM Unit

SUB ROM UNIT





1. Installing location: The valve body upper part
2. Function: To obtain A/T fluid pressure stability by compensating for solenoid & valve body unit fluid pressure differential.
3. Principle: Install additional ROM onto valve body of automatic transmission and input fluid pressure differential of solenoid & valve body so that TCM reads the input data to perform fluid pressure compensation.





4. Maintenance
1) When replacing with a new TCM in the vehicle
^ TCM automatically reads SUB ROM DATA during I.G ON. At this time, shift range valve is off for about 2.5 second.
2) When replacing A/T (regardless of new or old ones) in the vehicle
^ Must erase SUB ROM DATA stored in TCM.
^ With the ignition ON (engine OFF), maintain 50% throttle opening in R range while using the TCU SUB ROM RESET mode on the scan tool.
^ TCM reads SUB ROM DATA from a new A/T upon I.G ON again after I.G OFF.
3) Moving TCM from vehicle A to another vehicle B
^ Perform the same way as in 2) above.