Symptoms of a bad transmission solenoid switch include inconsistent shifting, delayed shifting or no shifting of the transmission, according to Transmission Repair Cost Guide. Dirty transmission fluid and electrical problems can cause the device to malfunction, affecting the transmission fluid pressure, which activates the shifting of gears.
When a transmission solenoid fails, the gearbox can get stuck in or skip a gear or refuse to shift gears, explains Transmission Repair Cost Guide. If the level of electric current is too high or too low, it may cause a delay in gear shifting, or the transmission may not shift at all. Dirty fluid can cause the solenoid to become stuck open or closed, and the transmission functions as if it is stuck in neutral.