B1814 – OBD-II DTC

OBD-II DTC B1814 – Wiper Rear Motor Down Relay Coil Circuit Failure

DTC B1814 meaning

DTC B1814 refers to a fault in the rear wiper motor down relay coil circuit. This diagnostic trouble code indicates that the vehicle’s onboard diagnostic system has detected an issue with the electrical circuit that controls the rear wiper motor’s downward operation. The rear wiper motor is responsible for clearing the rear windshield, and any malfunction in this circuit can affect its performance.

DTC B1814 symptoms

Common symptoms associated with DTC B1814 may include:

• Rear wiper motor not functioning
• Intermittent operation of the rear wiper
• Rear wiper motor running continuously
• Inability to control the rear wiper speed or position
• Dashboard warning lights illuminated

DTC B1814 causes

Several factors can lead to the occurrence of DTC B1814, including:

• Faulty rear wiper motor
• Defective relay or relay circuit
• Wiring issues such as shorts, opens, or corrosion
• Faulty body control module (BCM)
• Poor electrical connections

DTC B1814 seriousness

The seriousness of DTC B1814 can vary based on the vehicle’s usage and conditions. While it may not pose an immediate safety risk, a malfunctioning rear wiper can reduce visibility in adverse weather conditions, potentially leading to dangerous driving situations. It is advisable to address this issue promptly to ensure proper vehicle operation.

How to diagnose DTC B1814

To diagnose DTC B1814, follow these steps:

1. Use an OBD-II scanner to confirm the presence of DTC B1814.
2. Inspect the rear wiper motor and relay for visible damage or wear.
3. Check the wiring and connectors for signs of corrosion or loose connections.
4. Test the relay operation using a multimeter to ensure it is functioning correctly.
5. Verify the voltage and ground at the rear wiper motor connector.
6. Check the body control module for any related fault codes.

How to fix DTC B1814 step-by-step instructions

To fix DTC B1814, follow these step-by-step instructions:

1. Clear the DTC using an OBD-II scanner.
2. Inspect and repair any damaged wiring or connectors in the rear wiper motor circuit.
3. Replace the rear wiper motor if it is found to be faulty.
4. Replace the relay if it fails the testing procedure.
5. Ensure all connections are secure and free of corrosion.
6. Recheck the system by operating the rear wiper and monitoring for any new DTCs.

How to erase DTC B1814

To erase DTC B1814, follow these steps:

1. Connect an OBD-II scanner to the vehicle’s diagnostic port.
2. Turn the ignition key to the “On” position without starting the engine.
3. Navigate to the “Erase Codes” or “Clear DTCs” option on the scanner.
4. Confirm the action to clear the trouble codes.
5. Disconnect the scanner and start the vehicle to verify that the code does not reappear.

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