B1819 – Wiper Rear Motor Up Relay Coil Circuit Open

The ODBII code B1819 indicates that there is an open circuit in the rear wiper motor up relay coil, which means the relay is not receiving the necessary electrical signal to operate the rear wiper motor properly.

The severity of ODBII code B1819 is moderate.

Common Causes For: B1818 Wiper Rear Motor Up Relay Coil Circuit Failure

• Faulty rear wiper motor relay
• Open circuit in the relay coil wiring
• Corroded or damaged connectors
• Faulty rear wiper motor
• Blown fuse in the wiper circuit
• Short circuit in the wiring harness
• Malfunctioning body control module (BCM)

Common misdiagnosis for B1819 Wiper Rear Motor Up Relay Coil Circuit Open

• Faulty rear wiper motor
• Bad wiper switch
• Damaged wiring or connectors
• Faulty body control module (BCM)
• Incorrectly installed or malfunctioning relay
• Grounding issues
• Battery or power supply problems
• Corroded terminals or connections

Common Troubleshooting Steps

The OBD-II code B1819 indicates a problem with the rear wiper motor up relay coil circuit, specifically that the circuit is open. Here are some common troubleshooting steps to diagnose and potentially resolve this issue:

• Check the Vehicle’s Manual: Refer to the vehicle’s service manual for specific information about the rear wiper motor relay and its circuit. This will provide you with wiring diagrams and component locations.
• Visual Inspection:
• Inspect the wiring and connectors associated with the rear wiper motor and relay for any signs of damage, corrosion, or loose connections.
• Look for frayed wires, broken connectors, or any other physical damage.
• Test the Relay:
• Locate the rear wiper motor relay in the fuse box or relay panel.
• Remove the relay and test it using a multimeter to check for continuity. If the relay is faulty, replace it.
• Check the Fuse:
• Inspect the fuse associated with the rear wiper motor circuit. If the fuse is blown, replace it and see if the issue persists.
• Test the Wiper Motor:
• Disconnect the rear wiper motor and test it directly by applying power to it. If the motor does not operate, it may need to be replaced.
• Check for Ground:
• Ensure that the rear wiper motor has a good ground connection. Use a multimeter to check for continuity between the motor ground terminal and the vehicle chassis.
• Inspect the Control Switch:
• Check the rear wiper control switch for proper operation. If the switch is faulty, it may not be sending the correct signal to the relay.
• 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.
• Perform a Circuit Test:
• Use a multimeter to perform a voltage drop test on the circuit. Check for proper voltage at the relay and motor when the wiper switch is activated.
• Consult a Professional:
• If the issue persists after performing these steps, it may be best to consult a professional mechanic or technician who can perform more advanced diagnostics. By following these steps, you should be able to identify the cause of the B1819 code and take appropriate action to resolve the issue.