B1021low severityBody
TPMS Sensor Frequency Mismatch
on 2020 GMC Acadia 3.6L V6 · FWD
What this code means
One or more TPMS sensors are transmitting on a different frequency than the vehicle receiver expects.
Symptoms
- TPMS warning light on
- Some sensors not reading
- New sensor not recognized
Common causes
- Aftermarket sensor with wrong frequency
- European/Asian frequency sensor on US vehicle
- Mixed sensor brands
- Incorrect replacement sensor part number
Diagnostic steps
- Verify sensor frequency with TPMS tool
- Check sensor part number compatibility
- Compare sensor frequency to vehicle specification
- Test each sensor individually
Repair notes
Replace mismatched sensors with correct frequency sensors. US vehicles typically use 315 MHz, European/Asian use 433 MHz.
Other Body codes on this vehicle
B0001
Driver Frontal Stage 1 Deployment Control
B0002
Driver Frontal Stage 2 Deployment Control
B0003
Passenger Frontal Stage 1 Deployment Control
B0004
Passenger Frontal Stage 2 Deployment Control
B0005
Driver Knee Airbag Deployment Circuit
B0006
Passenger Knee Airbag Deployment Circuit
B0007
Rear Left Side Airbag Deployment Circuit
B0008
Rear Right Side Airbag Deployment Circuit
B0009
Rear Center Airbag Deployment Circuit
B0010
Driver Side Airbag Deployment