A Ford vehicle with the 5R55W/S/N transmission comes in with the malfunction indicator lamp (MIL) illuminated. When the PCM is scanned for codes, gear-ratio-error codes are stored as well as codes for what appear to be pressure-control-solenoid electrical-circuit faults.
In many shops, when a vehicle comes in with the possibility of electrically generated codes, the shop tries to diagnose the electrical codes before removing the transmission for other repairs. In most instances, the solenoid fault code cannot be solved, even after solenoid replacement, wire inspection and PCM replacement.
In some instances the transmission is removed from the vehicle for repair of the gear-ratio-error complaint even though the pressure-control-solenoid code problem has not been resolved.
When the transmission is reinstalled, the gear-ratio-error codes are gone and, mysteriously, so are the pressure-control-solenoid codes.
Definitions for code P0775 in some service manuals and scan tools describe this code as being electrically generated. Some manuals describe this code as both electrically and mechanically generated. This includes codes P0745 and P0975. This causes the technician to address these codes in the wrong direction. These are solenoid performance codes as a rule.
Pressure-control solenoids A, B and C are responsible for maintaining proper clutch pressure in their related gears.
For example, if a gear-ratio error in second or fifth gear is stored, a code will be stored for pressure control solenoid B because it supplies clutch pressure in 2nd and 5th gears (refer to chart below). This is why you most likely will also have gear-ratio-error codes P0732 and P0735 stored.
In most instances, when wear is present in the servo-pin bore, you will have gear-ratio codes stored in addition to the pressure-control-solenoid performance codes that relate to the gears controlled by the worn servo-pin bore. The charts below contain all transmission-related codes for these vehicles.
Gear-ratio-error codes are common on these transmissions because of wear in the servo-pin bore at relatively low mileage. Kits to repair the worn servo-pin bores in these transmissions and others are available.
Repair kits are available from Northland Transmission Inc. at www.servobore.com or 715-458-2617.
December 2006 Issue
Volume 23, No. 12
- Ford/Lincoln/Jaguar: Pressure-Control-Solenoid Performance Codes