LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Mazda >> 2021 >> 3 Select, 4D Hatchback, AWD >> Repair and Diagnosis (Single Page) >> Accessories & Equipment >> Drivers Assistance Systems - ADAS >> On-Board Diagnostic - Vehicle Control Module (1 Of 2) >> DTC B1B5A-49: Rear Side Ultrasonic Sensor (RH) Signal Circuit Malfunction [Vehicle Control Module] >> Outline
April 5, 2026: LEMON Manuals is launched! Read the announcement.

DTC B1B5A-49: Rear Side Ultrasonic Sensor (RH) Signal Circuit Malfunction [Vehicle Control Module]: Outline

DTC B1B5A:49 [VEHICLE CONTROL MODULE] DETECTION CONDITION AND POSSIBLE CAUSE

System malfunction location Rear side ultrasonic sensor (RH) signal circuit malfunction
Detection condition
  • The vehicle control module (VCM) detects that the parking assist unit (ultrasonic) determined that there is a malfunction in the rear side ultrasonic sensor (RH) signal circuit for 11 s.
Fail-safe (See DTC TABLE [VEHICLE CONTROL MODULE (US)] .)
Possible cause
  • Rear bumper malfunction
  • Rear side ultrasonic sensor (RH) connector or terminal malfunction
  • Parking assist unit (ultrasonic) connector or terminal malfunction
  • Short to ground in rear side ultrasonic sensor (RH) signal circuit
  • Short to power supply in rear side ultrasonic sensor (RH) signal circuit
  • Open circuit in rear side ultrasonic sensor (RH) signal circuit
  • Rear side ultrasonic sensor (RH) malfunction
  • Parking assist unit (ultrasonic) malfunction
G13718639Courtesy of MAZDA MOTORS CORP.