![]() ![]() Turning OFF N90 allows the K3 shift valve to send main line pressure to the K3 clutches, but because N92 is turned ON the K3-clutch regulator valve blocks the fluid from reaching the K3 clutches ( Figure 2). The 2-3 shift is initiated with the N90 (#3) (green) turned OFF and the N92 (#5) (blue) turned ON simultaneously ( Figure 1). ![]() The shift timing is controlled by the transmission control module (TCM), taking into consideration its learned adaptation settings. On the other hand, if the K3 clutches are applied too soon we get a 2-3 bind. If the B2 clutches are released too soon we get a 2-3 flare. This shift-solenoid state allows the K1 and B2 clutches to be applied. ![]() In second gear, shift solenoid N88 (#1) is OFF and shift solenoids N89 (#2) and N90 (#3) are both ON. To accomplish the 2-3 shift, the B2 clutches have to be released while the K3 clutches are being applied. When a solenoid reads battery voltage it means the solenoid is OFF, and when it reads less than 1 volt it is ON. Figure 1 shows the voltage readings obtained by back-probing each solenoid at the TCM we are reading voltage drop in reference to battery ground. Let’s start by explaining what takes place during a 2-3 shift in the 01M, using the ’98-and-up model. Most-common symptoms are bind-up or flare during the shift. The shift that is most likely to give us a problem when adaptations are not reset on the 01M transmission is the 2-3. Let’s use the most-recent case I had, a ’99 VW New Beetle with a 01M transmission that had a slight binding feel on the 2-3 shift. In this article I’ll use the VW 01M 2-3 shift to explain the hydraulic part of the adaptation. I have corrected many shift complaints from other shops that just could not get the transmission to shift properly simply by resetting the adaptations. In previous articles I have explained the important part that adaptations play in the shift quality and proper operation of a transmission. Issue: Slight binding feel on 2-3 shift. ![]()
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