Shift Pointers
- Author: Pete Luban, ATSG Technical Supervisor
Correcting 2-3 flare in Saturn’s AF33/23-5 requires reprogramming TCM
I happened to be looking through some newly received factory bulletins from GM and came across an interesting one concerning the Saturn Vue and Ion. These models that are equipped with the AF33/23-5 five speed automatic have been around since 2002.
Originally the Vue with a four-cylinder engine and an Ion coupe were equipped the VT25-E continuously variable transmission, but the engineers just couldn’t get it to work, so production of this transmission was ended, and all models of the Vue and Ion will now have the AF33/23-5 transmission.
The AF33/23-5 may look familiar to you if you’ve ever worked on a late-model Volvo with the 55-50SN. That’s because they are one and the same (see Figure 1).
This same transmission also is used in the 2004 and later Nissan Maxima and Quest minivan with the 3.5-liter engine. Nissan prefers to call this transmission the RE5F22A.
Anyway, back to the Saturn and this bulletin. The bulletin says the 2-3 flare is caused by aeration of the ATF resulting in a delayed application of the third clutch.
If the TCM has not had the latest revision to address the 2-3 flared shift, it should be done at this time. Obviously, if you do not do GM reflash, to the dealer it goes.
The thing that caught my attention was the manual relearn procedure that is necessary after repairs are made (you’re gonna love this), shown in Figure 2.
The TCM relearn procedure must be done after repairs; this is not an option. Failure to do so or omitting any steps of the procedure will give you erratic or harsh shifts and – guess what – a 2-3 flared shift and, for good measure, a flare on the 3-4 shift.
The bulletin further states that some models, depending on transaxle part number, should receive a new valve-body assembly before the TCM reflash is done and that you then should re-evaluate the vehicle as to whether the 2-3 flare still is present. Looks as though GM does what we do in some cases – throw a valve body at it and if it works, great; if it doesn’t, we’ll try something else (transmission repair is not an exact science).
The chart in Figure 3 shows the part number of the transaxles that may require a new valve body and the reflash calibration number that’s associated with it, as well as other pertinent vehicle information. The transaxle part number is on the metal tag on top of the unit (see Figure 4).
Whether you want to mess with this depends on your point of Vue, I guess (sorry about the pun).
