B1850

CIRCUIT DESCRIPTION
The driver seat module monitors the positions of most of the seat adjuster motors using hall effect type position sensors. The hall effect position sensors are supplied with battery positive reference and ground circuits from the driver seat module. The position sensor signal circuits are supplied battery positive voltage through a resistor then monitored within the driver seat module. During adjuster motor operation the hall effect position sensor provides a single pulse for every adjuster motor shaft rotation. The driver seat module counts the pulses from the position sensor signal circuits to determine the adjuster motor positions when storing or recalling memory seat position settings.

CONDITIONS FOR RUNNING THE DTC
The system voltage must be between 9.0-16.0 volts.

CONDITIONS FOR SETTING THE DTC
The driver seat module does not detect position sensor movement during adjuster motor operation.

ACTION TAKEN WHEN THE DTC SETS
- The affected seat adjuster motor will operate approximately 1 revolution and stop each time the adjuster switch is activated.
- The memory recall functions for the seat motor with a current status DTC will be disabled.
- When the fault is no longer present a history status DTC will be stored, and memory operation will be restored.

CONDITIONS FOR CLEARING THE DTC
- The DTC will be current for as long as the fault is present.
- When the fault is no longer present the DTC will be a history status code.
- The history DTC will be cleared after 100 error free ignition cycles, or by using the scan tool clearing DTCs feature.

TEST DESCRIPTION

Steps 1-4:

Steps 5-9:

Steps 10-13:

The numbers below refer to the step numbers on the diagnostic table.
3. During this test the driver seat module must see an active switch input before power will be supplied the position sensor.
4. During this test the driver seat module must see an active switch input before power will be supplied the position sensor.
5. During this test the driver seat module must see an active switch input before power will be supplied the position sensor.