B1620 – Wiper Rear Low Limit Input Circuit Open

The ODBII 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.

The severity of ODBII code B1620 is generally considered moderate.

Common Causes For: B1619 Wiper Rear Low Limit Input Circuit Failure

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

Common misdiagnosis for B1620 Wiper Rear Low Limit Input Circuit Open

• 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

Common Troubleshooting Steps

The OBD-II code B1620 indicates a problem with the rear wiper low limit input circuit, specifically that the circuit is open. This can be caused by various issues, including wiring problems, faulty components, or issues with the control module. Here are some common troubleshooting steps to diagnose and resolve the issue:

• 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.
• Visual Inspection:
• Inspect the wiring harness and connectors related to the rear wiper system for any signs of damage, corrosion, or loose connections.
• Look for frayed wires, broken connectors, or any signs of wear that could cause an open circuit.
• Test the Rear Wiper Motor:
• Check the rear wiper motor for proper operation. You can do this by applying direct power to the motor to see if it functions.
• If the motor does not operate, it may need to be replaced.
• Check the Limit Switch:
• The rear wiper system may have a limit switch that signals the position of the wiper. Test the switch for continuity using a multimeter.
• If the switch is faulty, it may need to be replaced.
• Inspect the Control Module:
• 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.
• If the module is suspected to be faulty, it may need to be reprogrammed or replaced.
• Check for Short Circuits:
• Use a multimeter to check for any short circuits in the wiring that could affect the rear wiper circuit.
• Ensure that the circuit is not shorted to ground or to another circuit.
• Clear the Code:
• 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.
• 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 make and model. By following these troubleshooting steps, you should be able to identify and resolve the issue related to the B1620 code.