What does it mean?
B2120 is a Body (airbags, seat belts, body electronics) fault code. It indicates: Adjustable Pedal Sensor .
Symptoms
- Passenger memory SET function will not store a position
- No confirmation feedback when the SET button is pressed
- Adjustable pedals will not move, or only move in one direction
- Memory recall moves the seat but leaves the pedals in the wrong place
- Fault sets again as soon as the code is cleared
- Occasional dead spot where the pedals stop partway through their travel
Likely causes
- Switch contacts held closed by dirt, wear or a liquid spill in the switch pack
- Trim panel or a loose clip pressing on the switch after a previous repair
- Switch input wire shorted to ground under the seat or in the door boot
- Adjustable pedal position sensor with a worn resistive track producing a dead spot
- Pedal assembly motor or screw drive jammed, holding the sensor out of range
- Connector at the pedal assembly loose or corroded from footwell moisture
- Poor ground for the memory module, distorting all measured inputs
- Memory or body module input failure once the wiring is proven
How to fix it
- Confirm the manufacturer definition and the pin assignments for this application
- Observe the SET switch state with nobody touching it, a constantly active state proves a stuck input or grounded wire
- Sweep the adjustable pedal through its full travel and look for drops or spikes in the position value
- Remove the trim and free the switch, then recheck the live data
- Unplug the switch to see whether the input clears, that separates a bad switch from a grounded harness
- Inspect the loom at the pedal assembly and along the seat rail for chafing and stretched wire
- Measure supply, ground and signal at the pedal sensor connector
- Repair or replace the faulty switch, sensor or wire, then store and recall a memory position to confirm the repair