GE ZBD5900 Technical Service Manual page 31

Wash Motor Circuit "Normal" Program selected with "Boost" option 142°F (step 22): The wash motor circuit operates
continuously from step 16 to step 18 ("Normal") and step 20 to step 24 ("Light").
The circuit is identical to step 13.
Timer Motor Circuit "Normal" Program selected with "Boost" option 142°F (step 22) - timer advance: A temperature
rise will cause the high thermostat (black dot) to close the circuit between the two terminals and provide a circuit to the timer
control terminal 12B.
From terminal 12B, the circuit is through the "High Temp" contacts on the timer control and then directly to (TM) on the timer
motor. Advancement of the timer motor will occur for 20 seconds to complete step 22.
Circuit Diagram: Circulate and Heat T+20 (Step 22) with Boost
30