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Home >> Mazda >> 2021 >> 6 Signature >> Repair and Diagnosis >> External Pages >> Different car >> Section 64 (On-Board Diagnostic - Front Body Control Module (FBCM)) >> DTC U0231-68: Communication Error With Humidity Sensor/Auto Light Sensor/Rain Sensor >> Notes
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DTC U0231-68: Communication Error With Humidity Sensor/Auto Light Sensor/Rain Sensor: Notes

WARNING: This page is about a different car, the 2018 Mazda 6. However, it is still accessible from the selected car via links, so may be relevant.
DTC U0231:68 (FRONT BODY CONTROL MODULE (FBCM)) DETECTION CONDITION AND POSSIBLE CAUSE

Description Communication Error With Humidity Sensor/Auto Light Sensor/Rain Sensor
Detection condition
  • Front body control module (FBCM) could not receive the signals from the humidity sensor/auto light sensor/rain sensor for 5 s or more with the ignition switched ON (engine off or on).
Fail-safe
  • Control is continued at the normal value right before malfunction.
Possible cause
  • Humidity sensor/auto light sensor/rain sensor connector or terminal malfunction
  • Front body control module (FBCM) connector or terminal malfunction
  • Short to ground in wiring harness between humidity sensor/auto light sensor/rain sensor terminal C and front body control module (FBCM) terminal 2G
  • Short to power supply in wiring harness between humidity sensor/auto light sensor/rain sensor terminal C and front body control module (FBCM) terminal 2G
  • Open circuit in wiring harness between humidity sensor/auto light sensor/rain sensor terminal C and front body control module (FBCM) terminal 2G
  • Humidity sensor/auto light sensor/rain sensor malfunction
  • Front body control module (FBCM) malfunction
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