A solenoid is an electrically powered switch. Automotive starter motors are the most familiar type of solenoid system, but many cars with automatic transmissions also have shift solenoids.
On 2003 Toyota Corollas, the shift solenoid is activated by a signal from a transmission computer control. This changes gears in the car at preset points.
According to Toyota, some 2003 Corollas may display the MIL (maintenance indicator light) "ON" with DTC (diagnostic trouble code) P0770 stored in the ECM (engine control module). This indicates a "Shift Solenoid E Malfunction" error. Toyota acknowledges that this is a common and known issue with the 2003 Corolla.
Likely reasons for shift solenoid errors on the 2003 Corolla range from an electrical fault to a bad torque converter clutch.
Solutions include a simple replacement computer chip for the transmission controller, a new solenoid or extensive work on the transmission. Commonly, it is the chip in the transmission controller that fails, and replacing this is the least expensive route to correcting the problem. Toyota has made production changes in later models of the Corolla line to eliminate the issue but has not issued a recall on the 2003 model.
