B1622 – Wiper Rear Low Limit Input Circuit Short To Ground

The ODBII code B1622 indicates a malfunction in the rear wiper system, specifically that the low limit input circuit is shorted to ground, which may prevent the rear wiper from functioning properly.

The severity of ODBII code B1622 is generally considered moderate.

Common Causes For: B1621 Wiper Rear Low Limit Input Circuit Short To Battery

• Damaged wiring or connectors in the rear wiper circuit.
• Short circuit in the rear wiper motor.
• Faulty rear wiper switch.
• Corroded or loose connections.
• Malfunctioning body control module (BCM).
• Water intrusion or moisture in the electrical components.

Common misdiagnosis for B1622 Wiper Rear Low Limit Input Circuit Short To Ground

• Faulty rear wiper motor
• Damaged wiring or connectors
• Malfunctioning body control module (BCM)
• Incorrectly installed or faulty wiper switch
• Short circuit in the wiring harness
• Corroded or loose ground connections
• Issues with the front wiper system affecting the rear wiper circuit

Common Troubleshooting Steps

The OBD-II code B1622 indicates a problem with the rear wiper low limit input circuit, specifically a short to ground. Here are some common troubleshooting steps to diagnose and resolve this issue:

• Visual Inspection:
• Check the wiring and connectors associated with the rear wiper system for any visible damage, fraying, or corrosion.
• Look for any signs of water intrusion or moisture that could affect the electrical components.
• Check the Rear Wiper Motor:
• Inspect the rear wiper motor for any signs of damage or wear.
• Ensure that the motor is properly connected and that the connectors are secure.
• Test the Circuit:
• Use a multimeter to check the continuity of the rear wiper low limit input circuit. Disconnect the connector from the rear wiper motor and test the circuit for continuity to ground.
• If there is continuity when the circuit should be open, there may be a short to ground somewhere in the wiring.
• Inspect the Ground Connections:
• Check the ground connections for the rear wiper motor and associated circuits. Ensure they are clean and secure.
• A poor ground connection can cause erratic behavior and trigger fault codes.
• Check for Shorts:
• Inspect the wiring harness for any signs of shorts to ground. Look for areas where the insulation may be damaged or where wires may be pinched or chafed against metal surfaces.
• Test the Wiper Switch:
• If applicable, test the rear wiper switch for proper operation. A faulty switch can send incorrect signals to the wiper motor.
• Scan Tool Data:
• Use an OBD-II scanner to check for any additional codes that may be present. Sometimes, multiple codes can provide more context for the issue.
• Monitor live data to see if the rear wiper motor is receiving the correct signals when the switch is activated.
• Repair or Replace Components:
• Based on your findings, repair any damaged wiring or connectors.
• If the rear wiper motor or switch is found to be faulty, replace them as necessary.
• Clear the Code:
• After making 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 Service Manual:
• If the issue persists, consult the vehicle’s service manual for specific wiring diagrams and troubleshooting procedures related to the rear wiper system. By following these steps, you should be able to identify and resolve the issue related to the B1622 code. If you’re not comfortable performing these steps, consider seeking assistance from a qualified mechanic.