High-Low Shift Motor

Fig 1: Identifying High-Low Shift Motor Components

Courtesy of ISUZU MOTOR CO.

When the TOD switch is changed to the 4L (or TOD) position from the TOD (or 4L) position, the TOD control unit drives the high-low shift motor according to the signal. The transfer is shifted to low range from high range (or to high range from low range) by the shift motor.

The high-low shift motor can run, only when the operation meets the following conditions to prevent an unexpected shift between high and low range by a operation error.

1. The car stops. (less than 2 km/h or 1.2 mph and less than 1500 rpm.)
2. The AT selector position is neutral.
3. The brake is applied. (brake switch is on.)

The shift motor has a built-in encoder which watches motor rotation position. The control unit controls the rotation of the shift motor based on the position code detected by the encoder.

The encoder position plate turns together with the shift shaft and switches on or off the current from the 4 (four) fixed contact points on the case, then the control unit recognizes the rotation position of the shift motor.