Power front seats without memory
The driver's seat without a position memory function works in all ignition power modes. Driver's seat without memory function only works when the ignition is set to power mode 6 (ignition).
Power for front passenger seat operation is supplied from the AJB through the passenger seat power relay to the passenger seat control switch box. Power for driver's seat operation is supplied directly from the AJB to the driver's seat control switch box. The power supply to the front passenger seat and the driver's seat is controlled by the CJB. When the seat control switch is pressed, the seat switch box sends voltage to the appropriate seat adjustment motor. Each seat adjustment switch has two pins. Both contacts are normally grounded.
The driver and passenger seat switch boxes are also connected in circuit with the battery power management timer relay located in the CJB and controlled by the CJB. The battery wattage control timer relay allows adjustment of the driver's and front passenger's seat within 10 minutes after the engine is turned off and in the appropriate ignition power mode. The 10-minute timer is reset if the appropriate ignition power mode is maintained and the driver's door is opened or closed. Operation of the driver's and front passenger's seat is immediately inhibited when the vehicle is centrally locked.
When the seat adjustment motor control switch is pressed, one of the pins is energized and the other pin remains grounded. Pressing the seat adjustment motor control switch in the opposite direction reverses voltage and ground, causing the motor to rotate in the opposite direction. In the event of a mechanism sticking, the internal thermal relay cuts off the voltage supply to the motor.
Power driver's seat with position memory
Driver's seat with memory function works when the ignition is set to power mode 4 (food accessories) and in power mode 6 (ignition), and does not work in mode 9 (engine starting).
The power to operate the memory driver's seat is supplied directly from the AJB to the seat control module. The memory seat switch block is connected to the seat control module, which controls the operation and stored position of the individual seat adjustment motors. The power seat control module is connected via the medium speed CAN bus to the CJB and the left and right door control modules.
The seat control module is also connected in circuit with the battery wattage regulator timer relay located in the CJB and controlled by the CJB. The battery wattage regulator timer relay allows seat adjustment for up to 10 minutes after the engine is turned off and in the appropriate ignition power mode. The 10-minute timer is reset if the appropriate ignition power mode is maintained and the driver's door is opened or closed. Operation of the driver's seat is immediately inhibited when the vehicle is centrally locked.
Requests to move the exterior mirrors to recall a stored position are transmitted via the medium speed CAN bus by the seat control module to the front door control modules. The front door control modules directly control the storage and recall of the stored exterior mirror positions. For more information, see the chapter: Rear-view mirrors (501-09 Rear-view mirrors, Description and operation).
Seat control module
The seat control module has driver selectable functions and automatic control functions.
Driver selectable features
- Recalling seat and exterior mirror settings
- Direct seat adjustment
Recall function for seat and exterior mirror settings
The memory recall function sets the driver's seat to a memorized position and is activated when the memory button of the switch box is pressed. To limit the power consumption when calling up adjustments, only the 2 seat adjustment motors are switched on at the same time. To further minimize current loading when power is applied to the motors, each of the two running motors is initiated in phase with a 10 millisecond delay. First there is a longitudinal displacement of the seat and a change in the angle of the backrest, and then the height of the seat cushion is adjusted.
When the seat switch module memory button is pressed, the seat control module sends a message on the medium speed CAN bus to the front door control modules. The door control modules then activate the recall of the stored exterior mirror positions. The instrument cluster information center will display memory recall messages when this function is activated.
The memory recall function works with two separate modes; The operation of each mode depends on the state of the vehicle when the seat position memory button is pressed.
Operating modes of the settings call function:
One click mode
When the vehicle is stationary and the switch box memory button is pressed, the settings recall function will operate in one-touch mode. One-push mode allows the seat and exterior mirrors to immediately move to the requested position stored in the memory.
If you adjust the seat position or press the memory button while recalling settings in one-touch mode, the current recall of settings will be canceled and the seat (and exterior mirrors via medium-speed CAN bus) immediately stop moving. The seat will then move in the direction that the switch was pressed.
Memory recall is also canceled immediately if the vehicle starts moving before the seat reaches the requested position.
Proportional mode
If the vehicle is in motion and the memory button of the switch box is pressed, the setting recall function will operate in proportional mode. Proportional mode recalls seat position (and exterior mirrors) while the memory switch is held down. When the memory button is released, memory recall stops immediately until the seat has reached the intended memory position.
In order to reach the intended position stored in the memory while the vehicle is moving, it is necessary not to release the memory button until all movements of the seat and exterior mirrors have been completed.
Direct seat adjustment function
The direct seat adjustment function is activated by pressing the seat adjustment switch on the switch block (tilt, horizontal movement or height movement).
When any of the seat adjustment switches is pressed, the motor will adjust in that direction until the switch is released. Only two seat adjustment motors can operate at the same time.
Auto control functions
The seat control module has the following automatic control functions:
- Jamming Detection Mode
- Standby mode
- Battery monitoring mode
Jamming Detection Mode
The system detects a Seat Movement Motor Stuck if, with the motor running, there is no change in the feedback input from the appropriate sensor for 200 milliseconds while movement is occurring on that axis.
If a jammed mechanism is detected by the seat control module, movement along the corresponding axis is canceled, as in the case of recalling the position from the memory (recalling a setting from memory), and when you press the switch (direct seat adjustment).
For all manual movements during direct seat adjustment, the seat control module memorizes and stores in memory the point at which the binding occurs. If movement continues past the stored sticking point, the stored position is deleted from the memory of the seat control module. This happens in all cases when the mechanism is displaced beyond the memorized jamming point (e.g. when pressing the switch for more than 2 seconds).
If the motor stops due to a stall (for example, due to difficulty in moving the seat), after removing the obstacle, movement along this axis can be restarted in order to pass a new sticking point. To do this, press and hold the corresponding switch for more than 2 seconds. If the switch is not pressed in such a way as to pass a new sticking point, this position will be stored in the memory of the seat control module as a full movement along the corresponding axis.
If the motor stops due to a loss of communication with the sensor (sensor or wiring fault), movement along this axis can be restarted to pass the sticking point. To do this, click on the appropriate switch. To do this, press and hold the corresponding switch for more than 2 seconds. In this way, motor control can be maintained when the feedback signal from the encoder is lost.
If a pulse signal is received from the transducer after movement is resumed, movement will continue until the switch is released or until a stall occurs again due to a jammed mechanism. If the feedback does not resume, the motor will only run for 0.5 seconds and then stop until the switch is released and pressed again for more than 2 seconds, after which the motor will be activated again for 0.5 seconds, etc. This so-called "jog mode".
In the event of a malfunction of the medium speed CAN data bus, the seat will operate in "creep mode".
NOTE: For diagnostic purposes, when the seat is operated in "creep mode" the medium speed CAN bus indication appears and the seat control module or CJB or door control modules are not shown connected to the medium speed CAN bus.
Standby mode
The seat control module has a standby mode to reduce power consumption to the minimum required.
If the seat control module cannot enter standby mode due to motor operation, a reset request, or a switch being pressed, it will enter standby mode immediately after the operation is completed.
NOTE: If memory adjustments are recalled, adjustments to all axes will be completed before the seat control module enters standby mode, not just the one being performed by the currently running motor.
The seat control module will wake up when it detects CAN bus activity.
Battery monitoring mode
The seat control module monitors the input power to make sure the battery voltage is sufficient to crank the engine. If the battery voltage drops below 10.5 V, the seat control module will ignore all mirror and seat memory recall requests until the voltage exceeds 11.0 V.
When the battery voltage drops below 8.5 V, the seat control module ignores all requests to move the seat until the voltage is greater than 9.0 V.
If the battery voltage is greater than 16.5V, the seat control module ignores all requests to move the seat until the voltage falls below 16.0V.
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