Ford or Mazda vehicles equipped with the FNR5/FS5A-EL transaxle may encounter solenoid performance diagnostic trouble codes before or after overhaul. These trouble codes may be misleading if using previous information for the 4F27E as it is almost identical to the FNR5.
One of the most common complaints ATSG receives on the tech line is related to P0771 Shift Solenoid E stuck Off. The trouble code flow chart indicates a multitude of items that can cause this particular code to set. The definition of this code should be Torque Converter Clutch stuck Off, as this is typically what causes this code to set.
The biggest issue that there is with diagnosing this code is related to solenoid function, identification and location on the valve body. Refer to Figure 1 for a solenoid application chart and a clutch application chart. It is important to thoroughly road test the vehicle and verify which gears are operating and which are not, as solenoid performance codes may set from internal component problems. For instance, the P0771 can set from Solenoid E not operating mechanically, but often it is because the torque converter clutch is not holding or the bushings in the stator are worn out.
To correct this condition, road test the vehicle and verify that all of the five forward speeds are good and watch for proper torque converter clutch operation. Note: P0771 can set when Engine
If this solenoid swap did not solve the problem, the problem could be the lock-up valve in the valve body, the stator bushings leaking in the pump or a bad torque converter clutch. The
solenoid identification and component application can be used for diagnosing other solenoid performancecodes. Figure 3 provides the additional valve body used in the 5 speed version of the 4F27E.
