What does it mean?
B2152 is a Body (airbags, seat belts, body electronics) fault code. It indicates: Driver's MPCS Unit Internal (EEPROM) Error .
Symptoms
- Rear part of the seat cushion will not raise or lower, or moves in one direction only
- Memory recall starts and then stops partway, leaving the seat in the wrong position
- New positions cannot be stored
- Motor clicks or hums without any movement
- Seat moves normally with the manual switch but not with memory recall
- The code sets again as soon as the affected motor is operated
Likely causes
- Position sensor or hall element inside the rear vertical motor worn or failed
- Object jammed under the seat stopping the motor part way through its travel
- Seat mechanism or lift links binding because of dirt, corrosion or lost grease
- Harness under the seat stretched, pinched or chafed by the seat sliding fore and aft
- Connector under the seat unplugged or damaged during cleaning or trim work
- Corroded terminals after a spill or damp carpet
- Learned end stop values lost, so the module compares against invalid limits
- Memory module internal fault, considered only after the motor and wiring check out
How to fix it
- Confirm the manufacturer definition and the pin assignment for this motor
- Slide the seat fully forward and back and remove anything trapped underneath
- Watch the rear vertical position value in live data through the whole travel and look for dropouts or a value stuck at a limit
- Inspect the loom under the seat over its full travel for stretching, pinching and chafing
- Check the connector for corrosion and make sure it is fully latched
- Measure supply, ground and signal at the motor connector while operating the switch
- Free or lubricate the mechanism, or replace the motor and sensor assembly if the count does not change as the seat moves
- Perform the seat position relearn or calibration procedure, then store and recall each memory setting to verify