B1798 – Lamp Turn Signal Front Output Circuit Failure

The ODBII code B1798 indicates a malfunction in the front turn signal output circuit, typically related to a failure in the circuit that controls the front turn signal lamps.

The severity of ODBII code B1798 is moderate.

Common Causes For: B1797 Lamp Headlamp Low-Beam Circuit Short To Ground

• Faulty turn signal relay
• Damaged wiring or connectors
• Short circuit in the turn signal circuit
• Faulty turn signal switch
• Burned-out front turn signal bulb
• Corroded or loose electrical connections
• Malfunctioning body control module (BCM)

Common misdiagnosis for B1798 Lamp Turn Signal Front Output Circuit Failure

• Faulty turn signal switch
• Bad wiring or connections
• Defective body control module (BCM)
• Malfunctioning relay
• Burnt-out bulbs
• Grounding issues
• Incorrectly installed aftermarket lighting
• Faulty fuse

Common Troubleshooting Steps

The OBD-II code B1798 indicates a “Lamp Turn Signal Front Output Circuit Failure.” This code typically relates to issues with the front turn signal circuit in a vehicle. Here are some common troubleshooting steps to diagnose and resolve the issue:

• Check the Turn Signal Bulbs:: Inspect the front turn signal bulbs for any signs of damage or burnout. Replace any faulty bulbs.
• Inspect the Turn Signal Socket:: Examine the bulb socket for corrosion, damage, or poor connections. Clean or replace the socket if necessary.
• Check Wiring and Connectors:: Inspect the wiring harness and connectors leading to the turn signal for any signs of damage, fraying, or loose connections. Repair or replace any damaged wiring.
• Test the Turn Signal Relay:: Locate the turn signal relay in the fuse box and test it for proper operation. Replace the relay if it is faulty.
• Examine the Fuse:: Check the fuse associated with the turn signal circuit. If the fuse is blown, replace it and see if the issue persists.
• 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.
• Inspect the Body Control Module (BCM):: The BCM controls various lighting functions, including turn signals. Check for any faults in the BCM and ensure it is functioning correctly.
• Perform a Visual Inspection:: Look for any signs of water intrusion or damage in the areas where the wiring and components are located.
• Test the Circuit:: Use a multimeter to test the voltage and ground at the turn signal connector. Ensure that the circuit is receiving power and that the ground is solid.
• Consult Wiring Diagrams:**
• Refer to the vehicle’s wiring diagrams to understand the circuit layout and identify any potential issues in the wiring path. 1
• Reset the Code:**
• After performing repairs, clear the code using an OBD-II scanner and take the vehicle for a test drive to see if the code returns. If the issue persists after following these steps, it may be necessary to consult a professional mechanic or technician for further diagnosis and repair.