B2115

DTCs B2115, B2120:

CIRCUIT DESCRIPTION
The Memory Seat Module (MSM) receives inputs from the seat and lumbar position sensors during memory recall, memory set, and easy exit functions. The potentiometers in the position sensors vary in resistance as the motor moves the seat and lumbar support. The MSM receives a variable voltage input depending on the resistance of the potentiometer. During memory set, the MSM records the voltage across all seat and lumbar potentiometers (only seat voltages are recorded for easy exit). During memory recall, the MSM moves the seat and lumbar motors until the voltage across each potentiometer matches the voltages stored. For the easy exit function, the MSM moves only the seat motors until the voltages match what the MSM has recorded in memory for the easy exit. During normal operation, the seat and lumbar position sensors are checked against out-of-range limits.

CONDITIONS FOR SETTING THE DTCS
Every 300 milliseconds the MSM checks the potentiometers (position sensors). If any of the potentiometer inputs goes out of range (0.25 V to 4.75 V), this Diagnostic Trouble Codes (DTC) will be set.

ACTION TAKEN WHEN THE DTC SETS
When a potentiometer sensor DTC is set as current, the Memory Seat Module will disable the affected motor during Memory Recall or Easy Exit operations. The motor will remain enabled for manual positioning.

CONDITIONS FOR CLEARING THE MIL/DTC
This DTC will be automatically cleared when the module does not detect a potentiometer out-of-range condition.

DIAGNOSTIC AIDS
A scan tool may be used to monitor Memory Seat Module sensor inputs.

TEST DESCRIPTION
The MSM contains software programs that perform periodic self tests. The entire diagnostic function is done within the MSM. Diagnostic results are reported over the Class 2 Data Link upon request from a scan tool.