B1021low severityBody

TPMS Sensor Frequency Mismatch

on 2015 Kia Forte 1.8L I4 · 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

  1. Verify sensor frequency with TPMS tool
  2. Check sensor part number compatibility
  3. Compare sensor frequency to vehicle specification
  4. 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

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