Ford/Mazda 4F27E/FN4A-EL Shifts from Second to Neutral
Complaint: A Ford with a 4F27E transmission was just overhauled and now has a complaint of a shift from second gear to neutral. Cause: This transmission needed to have the rear planetary that splines to the direct clutch hub, refer to figure 2, replaced, a planetary was taken from parts stock and installed. The planetary
Ford Focus 4F27E Harsh Garage Shifts
Complaint: A 2006 Ford Focus with the 4F27E Transmission has complaints of harsh garage shifts as well as harsh lift throttle coast downshifts. All upshifts are perfect and no trouble codes are stored. An exchange valve body complete with solenoids did not eliminate the complaints. The Mass Airflow Sensor was cleaned and checked and the
A ‘Guess Why’ Tech Article
A 2006 Ford Focus 2.3L with a 4F27E transmission comes into a shop with a complaint of a harsh garage shift into gear (drive and reverse), as well as harsh lift throttle coast downshifts. All forward upshifts are perfect. There are no codes stored in the system. In some cases, the transmission had been rebuilt, which included a different valve body and solenoids in an attempt to resolve the problem.
FNR5/4F27E and Code P0741
There are a couple of wear areas in the FNR5 and 4F27E that can cause converter-slip codes to set. Some of the factory trouble-code charts would lead you to believe that a solenoid was bad, because they send you to test the solenoid first. The best thing to do is to determine how the code is setting, and then you can determine where to look for the cause of the code.
A frequent call we receive on ATSG’s technical hotline with the 4F27E (FN4A-EL) transmission is a neutralizing shift going into fourth gear. The reason why it is such a frequent complaint is that there are several causes of this malfunction.
Ford 4F27E Shift Strategy – a Different Way of Doing Things
The 4F27E transmission uses two on/off solenoids and three PWM solenoids to produce each of the shifts and converter-clutch apply, as the chart in Figure 1 shows. The EPC solenoid is used to control line pressure relative to engine torque. So far this sounds easy, but from a strategy standpoint, it progressively moves toward a “different way of doing things” when compared with what we are accustomed to.