WOMS
B code body Medium severity

B1620 Wiper Rear Low Limit Input Circuit Open

The OBD2 code B1620 indicates that there is an open circuit in the rear wiper low limit input, meaning the vehicle's system is not receiving the expected signal from the rear wiper's low position sensor

Definition

The OBD2 code B1620 indicates that there is an open circuit in the rear wiper low limit input, meaning the vehicle's system is not receiving the expected signal from the rear wiper's low position sensor

Common causes

  • Faulty rear wiper switch
  • Damaged wiring or connectors
  • Defective rear wiper motor
  • Poor ground connection
  • Malfunctioning body control module (BCM)

Common misdiagnoses

  • Faulty rear wiper motor
  • Bad wiper switch
  • Damaged wiring or connectors
  • Malfunctioning body control module (BCM)
  • Incorrectly installed or defective rear wiper relay
  • Issues with the main fuse or power supply
  • Faulty ground connection

Troubleshooting steps

  1. 1. Check the Vehicle's Manual

    Refer to the vehicle's service manual for specific information about the rear wiper system and the B1620 code. This can provide insights into the wiring diagrams and component locations

  2. 2. Visual Inspection

  3. 3. Inspect the wiring harness and connectors related to the rear wiper system for any signs of damage, corrosion, or loose connections

  4. 4. Look for frayed wires, broken connectors, or any signs of wear that could cause an open circuit

  5. 5. Test the Rear Wiper Motor

  6. 6. Check the rear wiper motor for proper operation. You can do this by applying direct power to the motor to see if it functions

  7. 7. If the motor does not operate, it may need to be replaced

  8. 8. Check the Limit Switch

  9. 9. The rear wiper system may have a limit switch that signals the position of the wiper. Test the switch for continuity using a multimeter

  10. 10. If the switch is faulty, it may need to be replaced

  11. 11. Inspect the Control Module

  12. 12. The Body Control Module (BCM) or another control module may be responsible for the rear wiper operation. Check for any fault codes in the module and ensure it is functioning correctly

  13. 13. If the module is suspected to be faulty, it may need to be reprogrammed or replaced

  14. 14. Check for Short Circuits

  15. 15. Use a multimeter to check for any short circuits in the wiring that could affect the rear wiper circuit

  16. 16. Ensure that the circuit is not shorted to ground or to another circuit

  17. 17. Clear the Code

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

  19. 19. Consult a Professional

  20. 20. 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 make and model. By following these troubleshooting steps, you should be able to identify and resolve the issue related to the B1620 code