Shift Solenoids

The transmission uses two on/off type solenoids located in the rear valve body to control the shifting. MV1 is a normally closed solenoid used to activate the 1-2 and 3-4 shifts. MV2 is a normally open solenoid used to control the 2-3 shift. A significant difference between the THM-R1 and ZF electronic transmission is in the way the valves are switched electrically. The ZF systems switch the ground side while the THM-R1 has the solenoids sharing a common ground and the control unit switches the positive side of the circuit.

Shift Solenoid Logic

Gear 1 2 3 4

MV1 (1-2/3-4) off on on off
MV2 (2-3) on on off off