The 4L60 - E family of transmissions use 2 shift solenoids, initially called Shift Solenoid A & Shift Solenoid B, later changed to comply with OBD II (On Board Diagnostics revision 2) regulations to 1 - 2 Shift Solenoid & 2 - 3 Shift solenoid. By activating and deactivating the solenoids in a predetermined pattern by the PCM, 4 distinct gear ratios can be achieved. The shift solenoid pattern, also sometimes referred to as solenoid firing order, is as follows;
how many solenoids are in a 4l60e transmission
2 shift solenoids