WOMS
B code body Medium severity

B1894 Wiper Rear Motor Speed Sense Circuit Failure

The OBD2 code B1894 indicates a failure in the rear wiper motor speed sense circuit, which means there is a problem with the signal that monitors the speed of the rear wiper motor

Definition

The OBD2 code B1894 indicates a failure in the rear wiper motor speed sense circuit, which means there is a problem with the signal that monitors the speed of the rear wiper motor

Common causes

  • Faulty rear wiper motor
  • Damaged wiring or connectors
  • Poor ground connection
  • Failed wiper motor speed sensor
  • Corroded terminals
  • Short circuit in the circuit
  • Open circuit in the wiring harness
  • Malfunctioning body control module (BCM)

Common misdiagnoses

  • Faulty rear wiper motor
  • Bad wiring or connectors
  • Malfunctioning body control module (BCM)
  • Incorrectly diagnosed windshield wiper switch
  • Issues with the front wiper system
  • Battery or charging system problems
  • Faulty ground connections

Troubleshooting steps

  1. 1. Check the Vehicle's Manual

    Refer to the vehicle's service manual for specific information regarding the rear wiper motor and the associated wiring diagrams

  2. 2. Visual Inspection

    Inspect the rear wiper motor and its wiring harness for any visible damage, corrosion, or loose connections

  3. 3. Check the connectors for signs of wear or damage

  4. 4. Test the Rear Wiper Motor

    Use a multimeter to test the rear wiper motor for proper operation. You can apply direct power to the motor to see if it functions correctly

  5. 5. If the motor does not operate when powered directly, it may need to be replaced

  6. 6. Check the Speed Sense Circuit

    Inspect the speed sense circuit for continuity. Use a multimeter to check for any breaks or shorts in the wiring

  7. 7. Ensure that the circuit is not grounded or shorted to another circuit

  8. 8. Examine the Wiper Control Module

    If applicable, check the wiper control module for faults. This module may be responsible for sending signals to the rear wiper motor

  9. 9. Test the module for proper operation and replace it if necessary

  10. 10. Scan for Additional Codes

    Use an OBD-II scanner to check for any additional trouble codes that may provide more context or indicate related issues

  11. 11. Inspect the Fuse

    Check the fuse associated with the rear wiper motor. If the fuse is blown, replace it and see if the issue persists

  12. 12. Check for Ground Issues

    Ensure that the rear wiper motor has a good ground connection. A poor ground can lead to erratic behavior or failure

  13. 13. Clear the Code

    After performing repairs or replacements, clear the trouble code using an OBD-II scanner and take the vehicle for a test drive to see if the code returns

  14. 14. Consult a Professional

    If the issue persists after performing these steps, it may be best to consult a professional mechanic or technician who has experience with your specific vehicle model. By following these troubleshooting steps, you should be able to identify and resolve the issue related to the B1894 code