Driver Power Seat The driver power seat is controlled by the driver seat module (DSM). The DSM does not need to be configured, however the drive seat does need to be calibrated when the DSM is installed. The driver seat regulator control switch provides voltage to the DSM when activated. The neutral position of each driver seat regulator control switch position is a ground state through the seat regulator control switch contacts. A voltage input causes the DSM to power the appropriate motor until the input is removed. Ground is the normal state of the motor circuits through the DSM and is not switched to control the motors. The DSM internally switches the appropriate line from ground to power to adjust the motors.
As the seat is adjusted, the DSM constantly monitors the motor position sensors to record the current seat position. The DSM will remove power from the motor upon termination of the seat regulator control switch input or if the DSM does not see movement from the motor by monitoring the position sensor. The DSM must be calibrated to the seat track it is controlling. For additional information, refer to Seat Calibration. Once the DSM is calibrated to the seat track, it will only allow movement within the calibrated range.
Seat Calibration The DSM is calibrated using a scan tool. The calibration procedure automatically powers the driver power seat through its full range of motion and records the full stop positions by monitoring the motor position sensors. Once the full stop positions or range of the seat have been recorded, the DSM will only operate within the calibrated range. Any input attempting to drive the seat beyond the calibrated range will be ignored. This calibration is used for all seat control functions including manual switch control and memory recall positioning. During the seat calibration, the DSM may identify a function that is inoperative, such as a position sensor not changing. If the DSM identifies a concern that has a related diagnostic trouble code (DTC), the DSM will set the related DTC at the end of the validation procedure.
The calibration procedure powers the seat track adjustments to the end of their travel, which is determined by the DSM seeing a change of state in the motor position sensors. If there is a concern with the seat track or motor position sensor that limits the travel, the DSM will interpret the stopping point as the end of travel and store the position. The DSM is not able to determine if the seat has moved to its full travel position. It is only capable of monitoring and storing the amount of travel seen by the position sensor changing states.
For additional information on carrying out the power seat calibration procedure, refer to the scan tool operating manual.
Memory Seat Memory seat positioning can be recalled with the memory switches on the driver door panel or a programmed remote keyless entry transmitter. In either case, the DSM receives a memory recall 1 or 2 command from the driver door module (DDM) over the SCP communication network. The memory recall switches are a hardwired input to the DDM. The DDM also receives the remote keyless entry transmitter signals. Once a valid memory recall command is received from the DDM, the DSM moves the drivers seat to the position stored in memory by powering the appropriate motors and monitoring the motor position sensors until the position is reached.
Easy Exit/Easy Entry The easy exit function moves the seat backwards about two inches when the ignition key is removed from the ignition switch. The DSM receives a key out command over the SCP communication network and powers the driver seat rearward. This function will not operate if the seat is less than the travel distance to the end of the track, or the function has been deactivated at the message center driver personality settings. The DSM will also cancel this operation if a valid input command is received, such as the seat regulator control switch or memory recall request.
The DSM will record the current seat position before powering the seat for a easy exit function. This recorded position will be used to return the seat to this position on the easy entry operation. During easy entry operation, the seat is returned to the position previous to the easy exit operation. Easy entry operation will be cancelled if a valid input command is received by the DSM.
Passenger Power Seat The passenger power seat motors are hardwired to the passenger seat regulator control switch. The circuits are normally at ground through the seat regulator control switch. The individual circuit is switched to power when the specific adjustment position is selected.
Heated Seats The driver and passenger heated seats share a common battery and ignition feed. A separate shared ignition source supplies the heated seat switches. When the heated seat switch is pressed with the ignition switch in RUN, a momentary voltage signal is sent to the heated seat module. The heated seat module then supplies power to the heating element circuit. The cushion element and seat backrest element are wired in series and powered by the same output. The heated seat module also will ground the separate indicator circuit at the heated seat switch to indicate an ON state. The heated seat module will remain on until the heated seat switch is pressed and a momentary voltage signal is received, or until 10 minutes expire. If the ignition source is removed from the module, the heated seat module will enter an off state and will not return to ON until the switch is once again pressed with the ignition switch in RUN. The heated seat module is designed to heat the seat to 37.5°C (99.5°F) and maintain the temperature until time-out or switched off. This temperature is maintained by the heated seat module monitoring the temperature sensor located in the seat cushion element, and adjusting the current flow to the heating elements.
Inspection and Verification
- Verify the customer concern by operating the system.
- Visually inspect for obvious signs of mechanical or electrical damage.
Visual Inspection Chart Mechanical Electrical
