OBD-II DTC C1749 – Trailer Input Circuit Failure
DTC C1749 meaning
DTC C1749 refers to a “Trailer Input Circuit Failure.” This diagnostic trouble code indicates that the vehicle’s onboard diagnostic system has detected an issue with the circuit responsible for receiving signals from the trailer. This can affect various functions, including trailer lights and braking systems.
DTC C1749 symptoms
Common symptoms associated with DTC C1749 may include:
- Inoperative trailer lights
- Malfunctioning trailer brakes
- Warning lights on the dashboard
- Inconsistent trailer connection notifications
DTC C1749 causes
Several factors can lead to the occurrence of DTC C1749, including:
- Faulty wiring or connectors in the trailer input circuit
- Corrosion or damage to the trailer connector
- Defective trailer control module
- Issues with the vehicle’s body control module
- Improperly connected or malfunctioning trailer
DTC C1749 seriousness
The seriousness of DTC C1749 can vary based on the specific symptoms and the vehicle’s intended use. It is important to address this code promptly, as it can lead to:
- Increased risk of trailer-related accidents
- Inability to safely tow a trailer
- Potential damage to the vehicle’s electrical system
How to diagnose DTC C1749
To diagnose DTC C1749, follow these steps:
- Use an OBD-II scanner to confirm the presence of the code.
- Inspect the trailer connector and wiring for visible damage or corrosion.
- Check the vehicle’s body control module for any related codes.
- Test the trailer control module for proper operation.
- Verify the integrity of the trailer input circuit using a multimeter.
How to fix DTC C1749 step-by-step instructions
To fix DTC C1749, follow these steps:
- Repair or replace any damaged wiring or connectors in the trailer input circuit.
- Clean any corrosion found on the trailer connector.
- Replace the trailer control module if it is found to be defective.
- Ensure that the trailer is properly connected and functioning.
- Clear the DTC using an OBD-II scanner and test the system to ensure the issue is resolved.
How to erase DTC C1749
To erase DTC C1749, follow these steps:
- Connect an OBD-II scanner to the vehicle’s diagnostic port.
- Access the diagnostic menu and select the option to clear or erase trouble codes.
- Confirm the action and wait for the scanner to complete the process.
- Disconnect the scanner and perform a test drive to ensure the code does not reappear.