Programming And Operating The Seats Using The Memory

Fig 1: View Of Programming And Operating The Seats Using The Memory

Courtesy of VOLVO CARS CORPORATION

Programming

There are four buttons for programming seat positions:

three memory buttons called 1, 2 and 3
a programming button, MEM.

To program in a new seat position:

move the seat to the desired position
press MEM and one of the memory buttons at the same time.

Moving

To move the seat to the programmed position:

press the desired memory button and hold it in until the seat stops.

The button must be kept depressed for the seat to move. The seat stops if the button is released.

The seat stops moving when the position of the seat matches the position programmed into the memory. If another button is pressed the seat will stop moving. The seat will not move if no position is programmed.

The vehicle has door mirrors with memory. When the desired memory button is pressed, the mirrors are set to the programmed position. Information is sent from the power seat module, left (PSL) (3/26) to the power seat module, right (PSR) (3/27) and driver door module (DDM) (3/127) to set the door mirrors to the programmed position. The memory positions of the door mirrors are stored in the driver's door module (DDM) (3/126) and passenger door module (PDM). The door mirror position stored is the position of the mirrors when the seat position was programmed. The position of the door mirror on the driver's side is stored in the driver door module (DDM). The position of the door mirror on the passenger side is stored in the passenger door module (PDM).

When the seat is run, a maximum of two motors are activated at the same time. If all motors need to operate to reach the programmed position, there is an order of priority. Motor 1 (front-rear adjustment) and motor 2 (backrest adjustment) operate first.

Each seat motor has a Hall sensor which detects the present position of the seat. When one of the stepper motors for the seat is run, the control module counts the number of pulses from the Hall sensor. The Hall sensor counts the number of revolutions made by the motor by detecting a magnet on the motor shaft. This creates a pulse for each revolution of the motor.

When a seat position is stored, the information about the number of pulses counted from each motor is stored in a memory.

When one of the memory buttons is pressed in, the control module calculates which motors need to be run and in which direction to obtain the desired position.