B1813 – OBD-II DTC

OBD-II DTC B1813 – Lamp Backup Switch Input Circuit Short To Ground

DTC B1813 meaning

DTC B1813 refers to a diagnostic trouble code indicating a short to ground in the lamp backup switch input circuit. This code is part of the On-Board Diagnostics II (OBD-II) system, which monitors various vehicle components and systems for faults. The lamp backup switch is responsible for signaling the vehicle’s backup lights when the transmission is in reverse. A short to ground means that there is an unintended connection between the circuit and the ground, which can lead to improper functioning of the backup lights.

DTC B1813 symptoms

Common symptoms associated with DTC B1813 may include:

• Backup lights not functioning
• Illumination of the check engine light or warning light on the dashboard
• Possible issues with the vehicle’s reverse gear engagement
• Other electrical issues in the vehicle related to the backup light circuit

DTC B1813 causes

Several factors can lead to the occurrence of DTC B1813, including:

• Damaged wiring or connectors in the lamp backup switch circuit
• Faulty lamp backup switch
• Corrosion or poor connections in the circuit
• Short circuits caused by aftermarket modifications or repairs

DTC B1813 seriousness

The seriousness of DTC B1813 can vary depending on the specific vehicle and its use. However, it is generally considered a moderate issue because:

• It affects the functionality of the backup lights, which are crucial for safety when reversing.
• It may indicate underlying electrical problems that could affect other systems.
• Ignoring the issue could lead to further electrical failures or complications.

How to diagnose DTC B1813

To diagnose DTC B1813, follow these steps:

1. Use an OBD-II scanner to confirm the presence of the DTC B1813.
2. Inspect the wiring and connectors associated with the lamp backup switch for any visible damage or corrosion.
3. Test the lamp backup switch for proper operation using a multimeter.
4. Check for any short circuits in the wiring by performing continuity tests.
5. Review any recent repairs or modifications that may have affected the circuit.

How to fix DTC B1813 step-by-step instructions

To fix DTC B1813, follow these step-by-step instructions:

1. Disconnect the vehicle’s battery to ensure safety while working on the electrical system.
2. Inspect and repair any damaged wiring or connectors in the lamp backup switch circuit.
3. Replace the lamp backup switch if it is found to be faulty.
4. Ensure all connections are clean and secure, eliminating any corrosion.
5. Reconnect the battery and clear the DTC using an OBD-II scanner.
6. Test the backup lights to ensure they are functioning correctly.

How to erase DTC B1813

To erase DTC B1813 from the vehicle’s computer, follow these steps:

1. Connect an OBD-II scanner to the vehicle’s diagnostic port.
2. Turn on the vehicle’s ignition without starting the engine.
3. Navigate to the option to clear or erase trouble codes on the scanner.
4. Confirm the action to erase the DTC B1813.
5. Disconnect the scanner and start the vehicle to ensure the code does not reappear.

Recommended tools for OBD-II diagnostics

Explore our expert picks: The Best OBD2 Scanners for 2025

Easy-to-use Multimeter for reliable diagnostics: AstroAI Auto-ranging Multimeter

Some of the links on this page may be affiliate links, which means we may earn a small commission if you make a purchase. This helps us keep our DTC database up to date and provide valuable content for free. We only recommend products that we have tested and believe to be the best in their class.